Introduction: Unicompartmental knee arthroplasty (UKA) remains a cost effective option for treatment of medial compartment osteoarthritis of the knee. In carefully selected patients survival rates exceed 90% survivorship at ten years. Main indications for revision include progressive osteoarthritis in other compartments, component loosening and polyethylene bearing failure. However, within those patients who have been revised, there is a cohort of patients who are revised early, usually under seven years. Mechanical mal-alignment has been cited recently as a reason for
The purpose of the study was to review and present a series of
Though retear rates following rotator cuff repair are well established, we set out to review current literature to determine when early retears occurred (defined as <12m following surgery), and examine which pre- and post-operative variables might affect outcome. Pubmed, Medline, and CINAHL were searched for literature published from 2011 to 2021 using specific search terms. The inclusion criteria were studies reporting retear rates within 12 months of initial surgical repair. Exclusionary criteria were studies that included partial thickness tears, and studies that did not use imaging modalities within 12 months to assess for retears. PRISMA guidelines were followed, identifying a total of 10 papers. A combined total of 3372 shoulders included (Mean age 56 −67 years). The most common modality used to identify early retears were ultrasound scan and MRI. 6 of the 10 studies completed imaging at 0-3 months, 6 studies imaged at 3-6 months and 6 studies imaged at 6-12 months. Across all studies, there was a 17% early retear rate (574 patients). Of these, 13% occurred by 3 months, whilst the peak for retears occurred at 3-6 months (82%) and 5% occurred at 6-12 months. The risk of retear was higher in larger tears and extensive tendon degeneration. All studies apart from one documented a return to work/sport at 6 months post-operatively. Postoperative rehabilitation does not appear to alter retear rate, although data is limited with only 1 of 10 studies allowing active range of movement before 6 weeks. Retorn tendons had poorer functional outcomes compared to intact tendons at 12m following initial repair. The majority of early retears occur at 3-6 months and this time period should be prioritised both in rehabilitation protocols and future research. Age, tear size, and tendon degeneration were found to influence likelihood of early retears.
The Oxford medial unicompartmental knee replacement has been shown to provide good long-tern results in numerous studies with survivorship at 10 years ranging from 82% to 100%. This prospective study describes the survival of 265 Oxford unicompartmental knee replacements implanted in one centre from 1995-2009. 8 were lost to follow up. 40 of the 265 knees were revised. For operation performed from1995-1999 the risk of revision at 5 years was 10%, operations from 2000-2004 the risk of revision was 15% and from 2005-2009 the risk of revision at 5 years was 36%. This study demonstrates that since 2005 there has been a significant increase in
Purpose of study. To assess the risk of early re—dislocation following closed reduction (CR) of the hip for idiopathic developmental dysplasia of the hip (DDH). Methods. Review of case notes and radiographs of all who underwent CR for DDH between January 2005 and January 2010 was undertaken. Parameters recorded included sex, side of dysplasia, age at the time of attempted reduction and concomitant complications. The main outcome measure was clinical and radiographic evidence of successful reduction.
Background: Unicondylar knee arthroplasty (UKA) are being expanded to include younger patients with more active lifestyles because of its minimally invasive nature. Prior to expanding this role, it is important to examine mode of failure and implication of conversion to TKA in the low demand elderly patients. Aim: To ascertain the modes of
Introduction: The Gemini stem (DePuy) is a titanium femoral stem with a modular cobalt chrome femoral head. It has a roughened proximal surface finish to enhance cement bonding and a distal centraliser. Purpose of the study: A retrospective assessment of the performance of the titanium cemented Gemini femoral component. Patients and Methods: 196 patients underwent a 204 total hip replacements using a titanium cemented Gemini stem and an uncemented cup. All the operations were performed by a lateral approach using modern cementing technique. Patients were assessed clinically (Harris hip score) and radiologically (standard AP and lateral x-rays). Results: 11 patients with incomplete clinical and radiological follow-up were excluded from the study, leaving 185 patients (193 hips). 36 patients died with their total hip prosthesis in situ. The average age was 71 years and primary diagnosis was OA in the majority. The average follow-up was 70 months (range 35– 121). 29 of the hips have been revised. A further 11 were recognized as radiological failures. In 24, aseptic loosening or a broken stem was an indication for the revision. Mean time to revision was 3.1 years (range 1.5 to 7). Discussion: Our results indicate that there is a high incidence of
Introduction. Total hip prostheses which use a ceramic head within a metal liner are a relatively recent introduction. As such, survivorship rates from independent centres alongside explant analysis are rare. The early experience with this novel ceramic-on-metal (CoM) bearing couple is reported. Methods and Materials. All CoM hips implanted between 2008 and 2009 at a single hospital by a single surgeon were reviewed. Radiographs were analysed using EBRA software to determine acetabular cup inclination and anteversion angles. Blood metal ion concentrations were measured using inductively coupled plasma mass spectroscopy (ICPMS). Explants were measured for bearing surface and taper wear using a high precision co-ordinate measuring machine. The roughness of the articulating surfaces was measured with a non-contact profilometer. Results. In 54 patients 56 CoM hips were implanted. Mean (range) age was 64 years (34-87). There were 41 females and 15 males. Patients were followed-up for a mean of 1.5 years. Three hips were revised at mean of 1.2 years (2 female, 1 male) with a further 3 listed for revision under 1.5 years giving an overall failure rate of 10.7%. All these patients reported with pain. X-rays of failed devices showed a characteristic pattern of femoral stem loosening. Serum cobalt and chromium were less than 2 micrograms/L. Explant analysis of the three revised hips showed wear at the liner rim in each case. In two of these cases the wear extended completely around the circumference. The wear volumes were 4.1, 2.0 and 2.3mm3 respectively. The ceramic heads were unworn but some transfer of metal could be seen visually. There was no significant wear or deformation at the taper junctions. Typical ceramic head roughness values were 3nm Ra and so most of the surface area of the heads remained in a pristine condition. Discussion. The very high
Introduction:. Prompted by the success of hip and knee arthroplasty, total ankle replacement (TAR) has become increasingly popular as a treatment for end stage arthritic complaints of the ankle. Glazebrook et al proposed a three grade classification of complications to assist prediction of early implant failure. We have compared the experience of a tertiary referral centre in the UK to Glazebrook's proposed system. Method:. A retrospective review of the Sheffield Foot and Ankle Unit TAR database was performed from 1995 to 2010. All complications were recorded and categorised using Glazebrook's proposed system. Glazebrook described eight main complications of increasing severity. Low grade complications; Post operative bone fracture, Intra-operative bone fracture and wound healing problems were very unlikely to lead to revision. Medium grade complications; technical error and subsidence, lead to failure < 50% of the time. High grade complications; deep infection, aseptic loosening and implant failure lead to revision > 50% of the time. Results:. 217 TAR were implanted in 198 patients with a minimum follow up of 30 months. The complication rate was 23% with a revision rate of 17%. All complications recorded in our study except intraoperative bone fracture and wound healing had a failure rate of at least 50%. Conclusion:. The proposed classification system of Glazebrook et al was the first step towards an international system of classifying TAR complications. Most complications associated with TAR have a significant impact on the lifespan of a TAR. Glazebrook et al's proposed three tier system did not reliably reflect our experience. We would categorise complications as either high or low risk for
Open debridement, irrigation with implant retention and antibiotic treatment (DAIR) is an accepted approach for early prosthetic joint infections (PJI). Our aim was to design a score to predict patients with a higher risk of failure. From 1999 to 2014 early (<90 days) PJIs without signs of loosening of the prosthesis were treated with DAIR and were prospectively collected and retrospectively reviewed. The primary end-point was
The aim was to identify frequency and pattern of
The Charnley Elite femoral component was first introduced in 1992 as a new design variant of the original Charnley femoral component (De Puy, Leeds, UK) with modified neck and stem geometry. The original component had undergone few changes in nearly forty years and has excellent long-term results. Early migration of the new stem design was determined by Roentgen Stereophotogrammetric Analysis (RSA)1. Rapid early migration of a component relative to the bone, measured by RSA, is predictive of subsequent aseptic loosening for a number of femoral stems. As there was rapid early migration and rotation of the Charnley Elite stem, we predicted that the long-term results would be poor. An outcome assessment is indicated as stems of this type are still being implanted. One hundred Charnley Elite stems, implanted in our centre between 1994 and 1997 were included in a prospective, cross-sectional follow-up study. Outcome measures include validated clinical scores (Charnley hip score, Harris hip score and Oxford hip score) and radiological scores (Gruen classification) as well as revision rates over the past 10 years. The clinical follow-up supports the RSA predictions of
Over the past ten years we have seen a move to less invasive surgical approaches and simplification of OR procedures; hence, there has been a renewed interest in the use of rectangular wedge-taper design hip stems. I present a personal series of over five hundred Accolade (Stryker) stems with a high (6%)
The Kinemax Plus knee replacement has a reported 10 year survival of around 96%. However we found the survival rate of this implant in our cohort to be 75% at 9 years. No abnormalities were found for clinical and radiological parameters. At reoperation the most striking feature was that of significant ultra-high molecular weight polyethylene (UHMWPE) failure. Oxidative and structural analysis of the polyethylene components was therefore undertaken. Ten Kinemax Plus tibial inserts were analysed; one was a shelf-aged unused implant, the others were explants. An FTIR analysis of the data showed that oxidation is present in all samples. The degree of oxidation however varied with depth and location. Except for a sharp oxidative peak approximately half way into the sample, the shelf aged samples had a fairly constant level of oxidation. The retrieved implants had an overall higher level of oxidation in both bearing and non-bearing regions. The latter had less of a variation in oxidation which implies that in vivo loading exaggerates the degree of oxidation. In the non-articulating regions oxidation of the explants was found to peak often at the region of about 40% from the bottom surface in all retrieved samples. By contrast, most articulating region had two oxidative peaks; one occurring at approximately 1–1.5mm from the surface, which is consistent with findings on subsurface oxidation, and another occurring about 2–3mm from the bottom surface. SEM imaging provided evidence for the presence of fusion defects by indicating grain boundaries through-out the explants. This indicates a compromised material which is more susceptible to damage. Fatigue loading of the implant has also been seen to produce a subsurface stress maximum at approximately 1 to 2mm below the articulating surface. It is thought that maximum contact stresses within this region cause Type 1 and Type 2 defects to open or become more pronounced. This in turn will increase the local concentration of oxygenating material as it will be present in these defects and voids where surface areas are greater for oxidative reaction. We therefore hypothesise that these fusion defects are the cause for the
Objective The aim of this study was to prospectively study the effectiveness of external fixation for war injuries during the recent Gulf conflict. Patients and Methods We studied all patients seen at 202 Field Hospital, which received the majority of patients who had external fixators applied by the British Armed Forces. Results Fifteen patients had external fixators applied with follow-up available for 14 (15 external fixators). Of the 15, 13 (87%) required early revision or removal due to complications of the injury or the fixator. Seven required early removal at a mean of 9.1 days (range 1–19). Six required early revision at a mean of 5.9 days (range 1–22). Instability was a problem with 10 fixators (67%). Seven fixators were revised and 3 were removed. Pin loosening was noted with 5 fixators (33%) involving twelve pins. The cause was multifactorial, but was related to injury severity and frame design. A significant pin track infection developed at 14 pin sites (3 fixators – 20%). All 3 fixators were removed after a mean of 15.5 days (range 14–19). Only 2 fixators did not require early removal or revision. Conclusion We have demonstrated a high
Introduction: The Charnley Elite femoral component was first introduced in 1992 as a new design variant of the original Charnley femoral component (De Puy, Leeds, UK) with modified neck and stem geometry. The original component had undergone few changes in nearly forty years and has excellent long-term results. Early migration of the new stem design was determined by Roentgen Stereophotogrammetric Analysis (RSA). Rapid early migration of a component relative to the bone, measured by RSA, is predictive of subsequent aseptic loosening for a number of femoral stems. As there was rapid early migration and rotation of the Charnley Elite stem, we predicted that the long-term results would be poor. An outcome assessment is required as stems of this type are still being implanted. Materials and method: One hundred Charnley Elite stems, implanted in our centre between 1994 and 1997 were included in a prospective, cross-sectional follow-up study. Outcome measures include validated clinical scores (Charnley hip score, Harris hip score and Oxford hip score) and radiological scores (Gruen classification) as well as revision rates over the past 10 years. Results: The preliminary analysis results are given. The mean time to follow-up was 8.28 years. 20 patients have died due to causes unrelated to their operations. 10 patients had stem revisions: 9 for aseptic loosening and 1 for a peri-prosthetic fracture. This indicates a significant 10% failure rate of the prosthesis in less than 10 years. Preliminary clinical scores in the patients who had not undergone any subsequent surgery were adequate (Oxford Hip Score mean average of 23.9). Thirteen percent of radiographs analysed had evidence of loosening, giving an overall loosening rate of 14% at 8 years. Discussion and conclusion: The clinical follow-up supports the RSA predictions of
Aims: We have been alerted due to a high and
A higher than expected failure rate of the Zimmer Durom acetabular component has been reported. A study by Zimmer did not reveal a design defect. This study investigated impaction deformation of two cup designs. Eleven Durom cups and modular heads (Zimmer, Warsaw, IN) were retrieved at an average of 13.9 months. The Birmingham Hip Resurfacing (Smith &
Nephew, Memphis, TN) served as a control. Cups were impacted into a two-point acetabular loading model made of 30 grade urethane foam (Sawbones, Vashon, WA). A coordinate measuring machine with 2 micron (um) accuracy was used to map the inside diameters of the cups before, during and after impaction. Machinist’s dye was used to check head-cup contact. The Durom porous coating was essentially devoid of tissue ingrowth. Two heads used with size 62/56 Duroms had equatorial wear stripes. The outside diameter of the Durom was 2.93±0.03mm larger than the nominal diameter. Dome wall thickness was 3.23±0.07mm for the Durom and 6.08±0.65mm for the BHR (n=11). Inside diameters of all cups had less than 10um deviation from roundness before impaction and after removal from the model. The mean diametral deformation of the Durom was 89.8±14.8um, significantly greater than the BHR, 57.2±25.0um (p<
0.002). Non-impacted cups exhibited polar contact—circular areas of dye at the dome with no contact near the rim. Duroms with greater deformation exhibited linear contact—a 2cm band of dye extending from rim to rim with no contact on either side of the band. The Durom is a relatively thin-walled acetabular component with low clearance and an aggressive rim flare. Impaction of this cup into an acetabular model resulted in deformation which approached the diametral clearance. Maximal deformation with larger cups and warping of the articular surface correlated with observed wear stripes. The absence of residual cup deformation indicated deformation is a dynamic phenomenon which can be detected only under conditions simulating in vivo use. It is likely that impaction deformation, with consequent friction and wear, contributed to the
Aims: To determine the pathological changes in the femur following resurfacing hip arthroplasty and identify possible causes of
