This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed.Aims
Methods
The primary aim of this study is to assess the survival of the uncemented hydroxyapatite (HA) coated Trident II acetabular component as part of a hybrid total hip arthroplasty (THA) using a cemented Exeter stem. The secondary aims are to assess the complications, joint-specific function, health-related quality of life, and radiological signs of loosening of the acetabular component. A single-centre, prospective cohort study of 125 implants will be undertaken. Patients undergoing hybrid THA at the study centre will be recruited. Inclusion criteria are patients suitable for the use of the uncemented acetabular component, aged 18 to 75 years, willing and able to comply with the study protocol, and provide informed consent. Exclusion criteria includes patients not meeting study inclusion criteria, inadequate bone stock to support fixation of the prosthesis, a BMI > 40 kg/m2, or THA performed for pain relief in those with severely restricted mobility.Aims
Methods
Impaired fracture repair in patients with type 2 diabetes mellitus (T2DM) is not fully understood. In this study, we aimed to characterize the local changes in gene expression (GE) associated with diabetic fracture. We used an unbiased approach to compare GE in the fracture callus of Zucker diabetic fatty (ZDF) rats relative to wild-type (WT) littermates at three weeks following femoral osteotomy. Zucker rats, WT and homozygous for leptin receptor mutation (ZDF), were fed a moderately high-fat diet to induce T2DM only in the ZDF animals. At ten weeks of age, open femoral fractures were simulated using a unilateral osteotomy stabilized with an external fixator. At three weeks post-surgery, the fractured femur from each animal was retrieved for analysis. Callus formation and the extent of healing were assessed by radiograph and histology. Bone tissue was processed for total RNA extraction and messenger RNA (mRNA) sequencing (mRNA-Seq).Aims
Methods
Intertrochanteric fractures are common, accounting for nearly 30% of all fracture related admissions. Some have suggested that these fractures should be treated in community hospitals so as not to tax the resources of Level One trauma centers. Since many factors predictive of fixation failure are related to technical aspects of the surgery, the purpose of this study was to compare radiographic parameters after fixation comparing trauma fellowship trained surgeons to non-fellowship trained community surgeons to see if these fractures can be treated successfully in either setting. Using our hospital system's trauma database, we identified 100 consecutive patients treated with cephalomedullary nails by traumatologists, and 100 consecutive patients treated by community surgeons. Quality of reduction, neck shaft angle (NSA), tip-to apex distance (TAD) were compared. The mean TAD for the trauma group was 10mm compared to 21mm for the community group (p<0.001). The mean postoperative NSA for the trauma group was 133 degrees compared to 127 degrees for the community group (p<0.001). The mean difference in the NSA of the fractured side compared to the normal hip was 2.5 degrees of valgus in the trauma group compared to 5 degrees of varus for the community group (p<0.001). There were 93 good reductions in the trauma group compared to 19 in the community group (p<0.001). There were no poor reductions in the trauma group and 49 poor reductions in the community group (p<0.001). Fellowship trained traumatologists achieved significantly more accurate reductions and implant placement during cephalomedullary nailing of intertrochanteric hip fractures.
To identify variables independently associated with same-day discharge (SDD) of patients following revision total knee arthroplasty (rTKA) and to develop machine learning algorithms to predict suitable candidates for outpatient rTKA. Data were obtained from the American College of Surgeons National Quality Improvement Programme (ACS-NSQIP) database from the years 2018 to 2020. Patients with elective, unilateral rTKA procedures and a total hospital length of stay between zero and four days were included. Demographic, preoperative, and intraoperative variables were analyzed. A multivariable logistic regression (MLR) model and various machine learning techniques were compared using area under the curve (AUC), calibration, and decision curve analysis. Important and significant variables were identified from the models.Aims
Methods
The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after total knee arthroplasty (TKA). A retrospective cohort of 5,857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models.Aims
Methods
This systematic review aims to compare the precision of component positioning, patient-reported outcome measures (PROMs), complications, survivorship, cost-effectiveness, and learning curves of MAKO robotic arm-assisted unicompartmental knee arthroplasty (RAUKA) with manual medial unicompartmental knee arthroplasty (mUKA). Searches of PubMed, MEDLINE, and Google Scholar were performed in November 2021 according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “unicompartmental”, “knee”, and “arthroplasty”. Published clinical research articles reporting the learning curves and cost-effectiveness of MAKO RAUKA, and those comparing the component precision, functional outcomes, survivorship, or complications with mUKA, were included for analysis.Aims
Methods
Return to sport following undergoing total (TKA) and unicompartmental knee arthroplasty (UKA) has been researched with meta-analyses and systematic reviews of varying quality. The aim of this study is to create an umbrella review to consolidate the data into consensus guidelines for returning to sports following TKA and UKA. Systematic reviews and meta-analyses written between 2010 and 2020 were systematically searched. Studies were independently screened by two reviewers and methodology quality was assessed. Variables for analysis included objective classification of which sports are safe to participate in postoperatively, time to return to sport, prognostic indicators of returning, and reasons patients do not.Aims
Methods
Golf is a popular pursuit among those requiring total hip arthroplasty (THA). The aim of this study was to determine if participating in golf is associated with greater functional outcomes, satisfaction, or improvement in quality of life (QoL) compared to non-golfers. All patients undergoing primary THA over a one-year period at a single institution were included with one-year postoperative outcomes. Patients were retrospectively followed up to assess if they had been golfers at the time of their surgery. Multivariate linear regression analysis was performed to assess the independent association of preoperative golfing status on outcomes.Aims
Methods
Non-operative management of AIS can present practical and psychological challenges, as effective bracing requires a considerable investment of time in adolescence which is a formative point of physical and emotional development. The management team lacks input from the psychological team and thus, it would be prudent for the spinal teams to appreciate and deal with the psychosocial effects associated with bracing. We sought to investigate how bracing as a part of non-operative management of idiopathic scoliosis, is perceived among adolescents. We performed a search of CINAHL, Medline, AMED, PsychARTICLES, Psychology and Behavioral Sciences Collection and PsychINFO databases to identify qualitative research investigating the thoughts, feelings and experiences and attitudes of those undergoing bracing for AIS. Keywords used were (((“adoles∗” OR “young pe∗”) AND “idiopathic scoliosis”) AND “brac∗”) AND (“perce∗” OR “experience∗” OR “perspective∗” OR “attitude∗”). Ten research articles were identified using our search strategy. Only one article addressed our research question specifically. This reported that almost all adolescent patients experienced psychological difficulties during treatment and received most of their support from family and friends rather than health professionals. Our interpretation of the literature on this subject has yielded three recommendations for service providers. First, the policy ought to change to ensure that psycholological support is engrained within the treatment process; second, more information and advice must be given to patients and their families; and third, health professionals should appreciate and directly address in their consultations the psychological difficulties involved in brace wearing and the need for adequate support.Abstract
Total elbow arthroplasty (TEA) usage is increasing owing to expanded surgical indications, better implant designs, and improved long-term survival. Correct humeral implant positioning has been shown to diminish stem loading in vitro, and radiographic loosening in in the long-term. Replication of the native elbow centre of rotation is thought to restore normal muscle moment arms and has been suggested to improve elbow strength and function. While much of the focus has been on humeral component positioning, little is known about the effect of positioning of the ulnar stem on post-operative range of motion and clinical outcomes. The purpose of this study is to determine the effect of the sagittal alignment and positioning of the humeral and ulnar components on the functional outcomes after TEA. Between 2003 and 2016, 173 semi-constrained TEAs (Wright-Tornier Latitude/Latitude EV, Memphis, TN, USA) were performed at our institution, and our preliminary analysis includes 46 elbows in 41 patients (39 female, 7 male). Patients were excluded if they had severe elbow deformity precluding reliable measurement, experienced a major complication related to an ipsilateral upper limb procedure, or underwent revision TEA. For each elbow, saggital alignment was compared pre- and post-operatively. A best fit circle of the trochlea and capitellum was drawn, with its centre representing the rotation axis. Ninety degree tangent lines from the intramedullary axes of the ulna and humerus, and from the olecranon tip to the centre of rotation were drawn and measured relative to the rotation axis, representing the ulna posterior offset, humerus offset, and ulna proximal offset, respectively. In addition, we measured the ulna stem angle (angle subtended by the implant and the intramedullary axis of the ulna), as well as radial neck offset (the length of a 90o tangent line from the intramedullary axis of the radial neck and the centre of rotation) in patients with retained or replaced radial heads. Our primary outcome measure was the quickDASH score recorded at the latest follow-up for each patient. Our secondary outcome measures were postoperative flexion, extension, pronation and supination measured at the same timepoints. Each variable was tested for linear correlation with the primary and secondary outcome measures using the Pearson two-tailed test. At an average follow-up of 6.8 years (range 2–14 years), there was a strong positive correlation between anterior radial neck offset and the quickDASH (r=0.60, p=0.001). There was also a weak negative correlation between the posterior offset of the ulnar component and the qDASH (r=0.39, p=0.031), and a moderate positive correlation between the change in humeral offset and elbow supination (r=0.41, p=0.044). The ulna proximal offset and ulna stem angle were not correlated with either the primary, or secondary outcome measures. When performing primary TEA with radial head retention, or replacement, care should be taken to ensure that the ulnar component is correctly positioned such that intramedullary axis of the radial neck lines up with the centre of elbow rotation, as this strongly correlates with better function and less pain after surgery.
Hemiarthroplasty is a common procedure that is an attractive alternative to total arthroplasty because it conserves natural tissue, allows for quicker recovery, and has a lower cost. One significant issue with hemiarthroplasties is that they lead to accelerated wear of the opposing native cartilage, likely due to the high stiffness of the implant. The purpose of this study was to investigate the range of currently available biomaterials for hemiarthroplasty applications. We employed a finite-element (FE) model of a radial head implant against the native capitellum as our joint model. The FE model was developed in ABAQUS v6.14 (Dassault Systèmes Simulia Corp., Providence, RI, USA). A solid axisymmetric concave implant with seven different materials and the native radial head were evaluated, six modelled as elastic materials with different Young's moduli (E) and Poisson's Ratios (ν), and one modelled as a Mooney-Rivlin hyperelastic material. The materials investigated were CoCr (E=230 GPa, ν = 0.3), PEEK (E=3.7 GPa, ν = 0.36), HDPE (E=2.7 GPa, ν = 0.42), UHMWPE (E=0.69 GPa, ν = 0.49), Bionate 75D (E=0.288 GPa, ν = 0.39), Bionate 55D (E=0.039 GPa, ν = 0.45), and Bionate 80A (modelled as a Mooney-Rivlin hyperelastic material). A load of 100 N was applied to the radius through the center of rotation representing a typical load through the radius. The variable of interest was articular contact stress on the capitellum. The CoCr implant had a maximum contact stress over 114% higher than the native radial head. By changing the material to lower the stiffness of the implant, the maximum contact stress was 24%, 70%, 105%, 111%, 113%, and 113% higher than the native radial head for Bionate 80A, Bionate 55D, Bionate 75D, UHMWPE, HDPE, and PEEK respectively. This work shows that lowering implant stiffness can reduce the contact stress on cartilage in hemiarthroplasty implants. By changing the material below a Young's modulus of ∼100 MPa elevated stresses on the capitellum can be markedly reduced and hence potentially reduce or prevent degenerative changes of the native articulating cartilage. Low stiffness implant materials are not a novel concept, but to date there have been few that investigate materials (such as Bionate) as a potential load bearing material for implant applications. Further work is required to assess the efficacy of these materials for articular bearing applications.
Essex-Lopresti injuries are often unrecognized acutely with resulting debilitating adverse effects. Persistent axial forearm instability may affect load transmission at both the elbow and wrist, resulting in significant pain. In the setting of both acute and chronic injuries metallic radial head arthroplasty has been advocated, however there is little information regarding their outcome. The purpose of this study was to assess the efficacy of a radial head arthroplasty to address both acute and chronic Essex-Lopresti type injuries. A retrospective review from 2006 to 2016 identified 11 Essex-Lopresti type injuries at a mean follow-up of 18 months. Five were diagnosed and treated acutely at a mean of 11 days (range, 8 to 19 days) from injury, while 6 were treated in a delayed fashion at a mean of 1.9 years (range, 2.7 months to 6.2 years) from injury with a mean 1.5 (range, 0 to 4) prior procedures. The cohort included 10 males with a mean age was 44.5 years (range, 28 to 71 years). A smooth stem, modular radial head arthroplasty was used in all cases. Outcomes included range of motion and radiographic findings such as ulnar variance, capitellar erosion, implant positioning and implant lucency using a modification of the method described by Gruen. Reoperations, including the need for ulnar shortening osteotomy, were also recorded. Three patients in each group (55%) reported persistent wrist pain. The mean ulnar variance improved from +5 mm (range, 1.8 to 7 mm) to +3.7 mm (range, 1 to 6.3 mm) at the time of final follow-up or prior to reoperation. Three (50%) patients in the chronic group underwent a staged ulnar shortening osteotomy (USO) to correct residual ulnar positive variance and to manage residual wrist pain. There were no reoperations in the acute group. Following USO, the ulnar variance in those three cases improved further to +3.5, +2.1, and −1.1 mm. No radial head prostheses required removal. Capitellar erosion was noted in five (45%) elbows, and was rated severe in one, moderate in two, and mild in two. Lucency about the radial head prosthesis stem was noted in eight (73%) cases, and rated as severe in 2 (18%), based on Gruen zones. Treatment of acute and chronic Essex-Lopresti lesions with radial head arthroplasty often results in persistent wrist pain. In the chronic setting, a planned USO was often necessary to restore axial forearm stability after radial head arthroplasty. Essex-Lopresti lesions represent a rare clinical entity that are difficult treat, particularly in the chronic setting. Early recognition and management with a smooth stem modular radial head arthroplasty may provide improved outcomes compared to chronic reconstruction.
The role of anconeus in elbow stability has been a long-standing debate. Anatomical and electromyographic studies have suggested a potential role as a stabilizer. However, to our knowledge, no clinical or biomechanical studies have investigated its role in improving the stability of a lateral collateral ligament (LCL) deficient elbow. Seven cadaveric upper extremities were mounted in an elbow motion simulator in the varus position. An LCL injured model was created by sectioning of the common extensor origin, and the LCL. The anconeus tendon and its aponeurosis were sutured in a Krackow fashion and tensioned to 10N and 20N through a transosseous tunnel at its origin. Varus-valgus angles and ulnohumeral rotations were recorded using an electromagnetic tracking system during simulated active elbow flexion with the forearm pronated and supinated. During active motion, the injured model resulted in a significant increase in varus angulation (5.3°±2.9°, P=.0001 pronation, 3.5°±3.4°, P=.001 supination) and external rotation (ER) (8.6°±5.8°, P=.001 pronation, 7.1°±6.1°, P=.003 supination) of the ulnohumeral articulation compared to the control state (varus angle −2.8°±3.4° pronation, −3.3°±3.2° supination, ER angle 2.1°±5.6° pronation, 1.6°±5.8° supination). Tensioning of the anconeus significantly decreased the varus angulation (−1.2°±4.5°, P=.006 for 10N in pronation, −3.9°±4°, P=.0001 for 20N in pronation, −4.3°±4°, P=.0001 for 10N in supination, −5.3°±4.2°, P=.0001 for 20N in supination) and ER angle (2.6°±4.5°, P=.008 for 10N in pronation, 0.3°±5°, P=.0001 for 20N in pronation, 0.1°±5.3°, P=.0001 for 10N in supination, −0.8°±5.3°, P=.0001 for 20N in supination) of the injured elbow. Comparing anconeus tensioning to the control state, there was no significant difference in varus-valgus angulation except with anconeus tensioning to 20N with the forearm in supination which resulted in less varus angulation (P=1 for 10N in pronation, P=.267 for 20N in pronation, P=.604 for 10N in supination, P=.030 for 20N in supination). Although there were statistically significant differences in ulnohumeral rotation between anconeus tensioning and the control state (except with anconeus tensioning to 10N with the forearm in pronation which was not significantly different), anconeus tensioning resulted in decreased external rotation angle compared to the control state (P=1 for 10N in pronation, P=.020 for 20N in pronation, P=.033 for 10N in supination, P=.001 for 20N in supination). In the highly unstable varus elbow orientation, anconeus tensioning restores the in vitro stability of an LCL deficient elbow during simulated active motion with the forearm in both pronation and supination. Interestingly, there was a significant difference in varus-valgus angulation between 20N anconeus tensioning with the forearm supinated and the control state, with less varus angulation for the anconeus tensioning which suggests that loads less than 20N is sufficient to restore varus stability during active motion with the forearm supinated. Similarly, the significant difference observed in ulnohumeral rotation between anconeus tensioning and the control state suggests that lesser degrees of anconeus tensioning would be sufficient to restore the posterolateral instability of an LCL deficient elbow. These results may have several clinical implications such as a potential role for anconeus strengthening in managing symptomatic lateral elbow instability.
Previous biomechanical studies of lateral collateral ligament (LCL) injuries and their surgical repair, reconstruction and rehabilitation have primarily relied on gravity effects with the arm in the varus position. The application of torsional moments to the forearm manually in the laboratory is not reproducible, hence studies to date likely do not represent forces encountered clinically. The aim of this investigation was to develop a new biomechanical testing model to quantify posterolateral stability of the elbow using an in vitro elbow motion simulator. Six cadaveric upper extremities were mounted in an elbow motion simulator in the varus position. A threaded screw was then inserted on the dorsal aspect of the proximal ulna and a weight hanger was used to suspend 400g, 600g, and 800g of weight from the screw head to allow torsional moments to be applied to the ulna. An LCL injured (LCLI) model was created by sectioning of the common extensor origin, and the LCL. Ulnohumeral rotation was recorded using an electromagnetic tracking system during simulated active and passive elbow flexion with the forearm pronated and supinated. A repeated measures analysis of variance was performed to compare elbow states (intact, LCLI, and LCLI with 400g, 600g, and 800g of weight). During active motion, there was a significant difference between different elbow states (P=.001 pronation, P=.0001 supination). Post hoc analysis showed that the addition of weights did not significantly increase the external rotation (ER) of the ulnohumeral articulation (10°±7°, P=.268 400g, 10.5°±7.1°, P=.156 600g, 11°±7.2°, P=.111 800g) compared to the LCLI state (8.4°±6.4°) with the forearm pronated. However, with the forearm supinated, the addition of 800g of weight significantly increased the ER (9.2°±5.9°, P=.038) compared to the LCLI state (5.9°±5.5°) and the addition of 400g and 600g of weights approached significance (8.2°±5.7°, P=.083 400g, 8.7°±5.9°, P=.054 600g). During passive motion, there was a significant difference between different elbow states (P=.0001 pronation, P=.0001 supination). Post hoc analysis showed that the addition of 600g and 800g but not 400g resulted in a significant increase in ER of the ulnohumeral articulation (9.3°±7.8°, P=.103 400g, 11.2°±6.2°, P=.004 600g, 12.7°±6.8°, P=.006 800g) compared to the LCLI state (3.7°±5.4°) with the forearm pronated. With the forearm supinated, the addition of 400g, 600g, and 800g significantly increased the ER (11.7°±6.7°, P=.031 400g, 13.5°±6.8°, P=.019 600g, 14.9°±6.9°, P=.024 800g) compared to the LCLI state (4.3°±6.6°). This investigation confirms a novel biomechanical testing model for studying PLRI. Moreover, it demonstrates that the application of even small amounts of torsional moment on the forearm with the arm in the varus position exacerbates the rotational instability seen with the LCL deficient elbow. The effect of torsional loading was significantly worse with the forearm supinated and during passive elbow motion. This new model allows for a more provocative testing of elbow stability after LCL repair or reconstruction. Furthermore, this model will allow for smaller sample sizes to be used while still demonstrating clinically significant differences. Future biomechanical studies evaluating LCL injuries and their repair and rehabilitation should consider using this testing protocol.
Joint hemiarthroplasty replaces one side of a synovial joint and is a viable alternative to total joint arthroplasty when one side of the joint remains healthy. Most hemiarthroplasty implants used in current clinical practice are made from stiff materials such as cobalt chrome or ceramic. The substitution of one side of a soft cartilage-on-cartilage articulation with a rigid implant often leads to damage of the opposing articular cartilage due to the resulting reductions in contact area and increases in cartilage stress. The improvement of post-operative hemiarthroplasty articular contact mechanics is of importance in advancing the performance and longevity of hemiarthroplasty. The purpose of the present study was to investigate the effect of hemiarthroplasty surface compliance on early in-vitro cartilage wear and joint contact mechanics. Cartilage wear tests were conducted using a six-station pin-on-plate apparatus. Pins were manufactured to have a hemispherical radius of curvature of 4.7 mm using either Bionate (DSM Biomedical) having varying compliances (80A [E=20MPa], 55D [E=35MPa], 75D [E=222MPa], n=6 for each), or ceramic (E=310GPa, n=5). Cartilage plugs were cored from fresh unfrozen bovine knee joints using a 20 mm hole saw and mounted in lubricant-containing chambers, with alpha calf serum diluted with phosphate buffer solution to a protein concentration of 17 g/L. The pins were loaded to 30N and given a stroke length of 10 mm for a total of 50,000 cycles at 1.2 Hz. Volumetric cartilage wear was assessed by comparing three-dimensional cartilage scans before and during wear testing. A two-way ANOVA was used for statistical analysis. To assess hemiarthroplasty joint contact mechanics, 3D finite element modelling (ABAQUS v6.12) was used to replicate the wear testing conditions. Cartilage was modeled using neo-Hookean hyper-elastic material properties. Contact area and peak contact stress were estimated. The more compliant Bionate 80A and 55D pins produced significantly less volumetric cartilage wear compared with the less compliant Bionate 75D and ceramic pins (p 0.05). In terms of joint contact mechanics, the more compliant materials (Bionate 80A and 55D) had significantly lower maximum contact stress levels compared to the less compliant Bionate 75D and ceramic pins (p < 0 .05). The results of this study show a relationship between hemiarthroplasty implant surface compliance and early in vitro cartilage wear, where the more compliant surfaces produced significantly lower amounts of cartilage wear. The results of the joint contact mechanics analysis showed that the more compliant hemiarthroplasty materials produced lower maximum cartilage contact stresses than the less compliant materials, likely related to the differences in wear observed. More compliant hemiarthroplasty surfaces may have the potential to improve post-operative cartilage contact mechanics by increasing the implant-cartilage contact area while reducing peak contact stress at the implant-cartilage interface, however, such materials must be resistant to surface fatigue and longer-term cartilage wear/damage must be assessed.
There are comparatively few randomized studies evaluating knee arthroplasty prostheses, and fewer still that report longer-term functional outcomes. The aim of this study was to evaluate mid-term outcomes of an existing implant trial cohort to document changing patient function over time following total knee arthroplasty using longitudinal analytical techniques and to determine whether implant design chosen at time of surgery influenced these outcomes. A mid-term follow-up of the remaining 125 patients from a randomized cohort of total knee arthroplasty patients (initially comprising 212 recruited patients), comparing modern (Triathlon) and traditional (Kinemax) prostheses was undertaken. Functional outcomes were assessed with the Oxford Knee Score (OKS), knee range of movement, pain numerical rating scales, lower limb power output, timed functional assessment battery, and satisfaction survey. Data were linked to earlier assessment timepoints, and analyzed by repeated measures analysis of variance (ANOVA) mixed models, incorporating longitudinal change over all assessment timepoints.Aims
Methods
Aims
Patients and Methods
Periprosthetic joint infections (PJI) are increasing in prevalence and are recognised as one of the most common modes of failure of joint replacements. Osteomyelitis arising from PJI is challenging to treat, difficult to cure and increases patient mortality 5-fold. PJI can have subtle symptoms and lie dormant or go undiagnosed for many years, suggesting persistent bacterial infection.
Our goal is to repurpose drugs to block the growth of lung metastases, the lethal process in osteosarcoma. We therefore screened the NCI-panel of 114 FDA-approved oncology drugs to identify agents that potently reduce growth of osteosarcoma spheroids (sarcospheres). We first developed a system to routinely generate large numbers of highly-uniform spherical sarcospheres (1/well) with a 400um diameter, to most closely simulate micrometatases. Our primary drug screen (Z’-factor=0.70+0.10) utilized sarcospheres from three highly-metastatic human osteosarcoma cell lines (LM7, 143B, and MG63.3) in the presence and absence of MAP chemotherapeutics. Dose-response experiments with 13 of the most effective drugs confirmed initial results and allowed comparison with each drug's toxicity on normal human osteoblasts and normal small airway epithelial cells. Romidepsin, a HDAC inhibitor (HDACi), had the most favorable toxicity/efficacy ratios (TD50/IC50=57–580, depending on cell line). The only other HDACi in the panel of FDA-approved drugs (vorinostat) also ranked highly in the screen. Since newer HDACi's may have improved toxicity/efficacy ratios, we compared romidepsin and vorinostat with the three other HDACi's that are FDA-approved (belinostat, panobinostat, and valproic acid) plus one that is in clinical trials (entinostat). Romidepsin (Cmax/IC50=36–360) and belinostat (Cmax/IC50=14–20) reduced sarcosphere growth at clinically-achievable levels, in the presence or absence of MAP. Importantly, both romidepsin and belinostat were synergistic with MAP (BLISS scores=5–15). Propidium iodide staining showed that both romidepsin and MAP substantially induced cell death throughout the sarcospheres. Our results strongly support future studies to determine effects of romidepsin and belinostat on growth of lung metastases
Dunkin Hartley guinea pigs, a commonly used animal model of osteoarthritis,
were used to determine if high frequency ultrasound can ensure intra-articular
injections are accurately positioned in the knee joint. A high-resolution small animal ultrasound system with a 40 MHz
transducer was used for image-guided injections. A total of 36 guinea
pigs were anaesthetised with isoflurane and placed on a heated stage.
Sterile needles were inserted directly into the knee joint medially,
while the transducer was placed on the lateral surface, allowing
the femur, tibia and fat pad to be visualised in the images. B-mode
cine loops were acquired during 100 µl. We assessed our ability
to visualise 1) important anatomical landmarks, 2) the needle and
3) anatomical changes due to the injection. Objective
Methods
Recently there has been interest in an alternative method of aligning a total knee arthroplasty (TKA) referred to as kinematic alignment. The theoretical appeal of this method is that alignment of each patient's knee can be individualized through the use of preoperative imaging and computer software, with the goal of achieving pre-arthritic alignment through restoration of the axes of rotation of each particular knee. Clinical studies have evaluated the outcomes of this new alignment technique, but to date there have been no randomized controlled trials comparing kinematic alignment to mechanical alignment. This randomized controlled trial was conducted to compare kinematically aligned and mechanically aligned TKA outcomes of knee pain, function and motion at two years' post-op, along with a comparison of limb, knee, and implant alignment of the two methods. Forty-four patients were surgically treated with kinematically aligned TKA (figure 1) with the use of patient specific guides, and forty-four patients were surgically treated with mechanically aligned TKA with the use of conventional instruments. All patients underwent CT long leg scanograms after surgery, and outcomes data were collected at a minimum of 2 years. The patient, radiographic evaluator, and clinical evaluator were blinded as to the alignment method.Introduction:
Methods and Materials:
The coronoid and collateral ligaments are key elbow stabilizers. When repair of comminuted coronoid fractures is not possible, prosthetic replacement may restore elbow stability. A coronoid prosthesis has been designed with an extended tip in an effort to augment elbow stability in the setting of residual collateral ligament insufficiency. The purpose of this biomechanical study, therefore, was to compare an anatomic coronoid replacement with an extended tip implant both with and without ligament insufficiency. Two coronoid prostheses were designed and developed based on CT-derived images adjusted for cartilage thickness: an anatomical implant and an extended-tip implant. Passive elbow extension was performed in 7 cadaveric arms in the varus and valgus positions. Varus-valgus laxity of the ulna relative to the humerus was quantified with a tracking system with an intact coronoid, a 40% coronoid deficiency, an anatomical prosthesis, and an extended prosthesis, with the collateral ligaments sectioned and repaired.Purpose
Method
Limited information is available regarding the functional outcomes of radial head fractures managed with open reduction and internal fixation (ORIF). The purpose of this study was to determine the functional outcomes of radial head fractures treated with ORIF. Fifty-two patients, with a mean age of 4412 years, who were treated with radial head ORIF were evaluated at a mean of 4.42.4 years. Thirty were isolated radial head fractures (Group A), 13 (Group B) were associated with a complex fracture-dislocation (terrible triad variants), and 5 (Group C) were associated with a proximal ulnar fracture (Monteggia/trans-olecranon variants). Fourty-four were partial articular fractures and 8 were complete articular fractures. Outcomes were assessed with physical and radiographic examination, and validated self-reported questionnaires.Purpose
Method
Radial head implant over-lengthening, a common cause of capitellar wear and clinical failure, is difficult to diagnose using radiographs of the injured elbow. The purpose of this study was to determine if a novel measurement technique based on contralateral elbow radiographs, termed the RACER method, could be used to accurately estimate the magnitude of radial head implant over-lengthening. Part I of this study examined the side-to-side consistency of radiographic landmarks used in the measurement technique. Part II of this study validated the technique using simulated radial head implant over-lengthening in a cadaveric model. Part I: A side-to-side comparison of elbow joint dimensions was performed in 50 patients (100 radiographs). Part II: Radial head prostheses of varying lengths (0,+2mm,+4mm,+6mm,+8mm) were implanted in 4 paired cadaveric specimens (8 elbows). Radiographs were obtained and measurements were performed by 2 examiners blinded to implant size to determine if contralateral radiographs could diagnose and provide a valid estimate of the magnitude of implant over-lengthening. Intra and inter-rater reliability was determined.Purpose
Method
There have been a number of described techniques for sizing the diameter of radial head implants. All of these techniques, however, are dependent on measurements of the excised native radial head. When accurate sizing is not possible due to extensive comminution or due to a previous radial head excision, it has been postulated that the proximal radioulnar joint (PRUJ) may be used as an intraoperative landmark for correct sizing. The purpose of this study was to: 1) determine if the PRUJ could be used as a reliable landmark for radial head implant diameter sizing when the native radial head in unavailable, and (2) determine the reliability of measurements of the excised radial head. Twenty-seven fresh-frozen denuded ulnae and their corresponding radial heads (18 males, 9 females) were examined. The maximum diameter (MaxD), minimum diameter (MinD) and dish diameter (DD) of the radial heads were measured twice, 3–5 weeks apart, using digital calipers. Two fellowship-trained upper extremity surgeons, an upper extremity fellow and a senior orthopedic resident were then asked to independently select a radial head implant diameter based on the congruency of the radius of curvature of the PRUJ to that of the radial head trial implants. The examiners were blinded to the native radial head dimensions. This selection was repeated 3–5 weeks later by two of the investigators. Correlation between radial head measurements and radial head implant diameter sizes was assessed using Pearsons correlation coefficient (PCC) and inter and intra-observer reliability were assessed using intra-class correlation coefficient (ICC).Purpose
Method
Current coronoid fracture classification systems are based on fragment size and configuration using plain radiographs and/or CT. During surgery, coronoid fracture fragments appear much larger than anticipated because cartilage is radiolucent and therefore not taken into account with preoperative imaging. The purpose of this study was to quantify the articular cartilage thickness of the coronoid process, with reference to coronoid fracture classifications. Twenty-four cadaveric ulnae were dissected, imaged, and analyzed using the OsiriX software program (3.6–64 bit, Geneva). Thirteen identifiable landmarks were chosen on the coronoid, olecranon and proximal radioulnar joint to measure articular cartilage thickness. Intra-observer and inter-observer reliability were calculated.Purpose
Method
The coronoid process is an integral component for elbow stability. In the setting of a comminuted coronoid fracture, where repair is not possible, a prosthetic device may be beneficial in restoring elbow stability. The hypothesis of this in-vitro biomechanical study was that an anatomic coronoid prosthesis would restore stability to the coronoid deficient elbow. A metal coronoid prosthesis was designed and developed based on CT-derived images adjusted for cartilage thickness. The kinematics and stability of eight fresh-frozen male cadaveric arms (mean age 77.4 years, range 69–92 years) were quantified in the intact state; after collateral ligament sectioning and repair (control state); after a simulated 40% transverse coronoid fracture; and after implantation of a coronoid prosthesis. Elbow flexion was simulated passively with the arm oriented in the varus position and the forearm in pronation. Varus-valgus angulation (VV) and internal-external rotation (IE) of the ulna relative to the humerus were quantified with an electromagnetic tracking system (Flock of Birds, Ascension Technologies, Burlington, VT, static accuracy: 1.8mm position, 0.5 orientation).Purpose
Method
Capitellum hemiarthroplasty is an emerging concept. The current metallic capitellar implants have spherical surface shapes, but the native capitellum is not spherical. This study evaluated the effect of capitellar implant shape on the contact mechanics of the radiocapitellar joint when articulating with the native radial head. Eight paired radii and humeri were potted in a custom jig. Articular casts were made with medium-viscosity resin while 85 N of axial load was applied to the reduced radiocapitellar joint at 0, 45, and 90 of elbow flexion, and at neutral, 50 pronation and 50 supination at each flexion angle. The native radiocapitellar articulation was compared to capitellar hemiarthroplasties of two surface designs (anatomical and spherical). Contact area and shape (circularity) were determined. Circularity was defined as the ratio of the minor axis and major axis of the shape.Purpose
Method
Release of tight lateral structures is an integral part of balancing the valgus knee during knee replacement surgery. The posterolateral capsule is released through an inside-out technique. The common peroneal nerve is in close proximity to the capsule during this step. This study was undertaken to determine the distance of the nerve and the safe level for the posterolateral release. MR scans of the knee of 100 patients were evaluated. The age range of selected patients was 50 to 70 years. The distance of the nerve was measured to the closest point on the posterolateral capsule. Two separate measurements were taken - one 9mm above the joint line indicating the distal femoral resection level and the other 9mm distal to the joint line indicating the level of tibial resection. A third point was at the joint line level. The position of the nerve was also recorded in relation to the cross section of the femur/tibia on a ‘clock-like’ reference.Purpose of the study
Methods
Rapid prototyping (RP), especially useful in surgical specialities involving critical three-dimensional relationships, has recently become cheaper to access both in terms of file processing and commercially available printing resources. One potential problem has been the accuracy of models generated. We performed computed tomography on a cadaveric human patella followed by data conversion using open source software through to selective-laser-sintering of a polyamide model, to allow comparative morphometric measurements (bone No significant differences in the dimensional measurements could be demonstrated. These data provide us with optimism as to the accuracy of the technology, and the feasibility of using RP cheaply to generate appropriate models for operative rehearsal of intricate orthopaedic procedures.
Hip resurfacing arthroplasty is an established and effective intervention for osteoarthritis of the hip in the young active patient, relying on the principle of femoral bone-stock preservation. A recognised mode of failure is neck thinning leading to radiological evidence of neck collapse and clinical failure. We report on a series of these slow-neck-failure patients and highlight the increased incidence of this phenomenon in post-menopausal female patients. This is a single operator, single implant series; 172 cases were identified from databases at our institution. 76 were female, mean (SD) age 52 (7) years. 96 were male, mean (SD) age 51(12) years. 15 (8.7%) patients required revision. 12 (80%) were female, 9 (75%) of these were due to slow neck failure. In the men one patient developed ALVAL requiring removal of his bilateral hip resurfacings, the other failure mode was early femoral neck failure. Mean time to failure was 6 months in men and 37 months in women. This difference in failure rates is also seen in the NJR figures. This review confirms the relatively high incidence of premature failure in post-menopausal females. NICE guidance in 2003, currently under review, stated that resurfacing is indicated in male patients up to 65 and female patients up to 60. As a result of this study we are currently advising post-menopausal patients that this risk of early failure may make total hip replacement a preferable option to resurfacing arthroplasty.
Osteonecrosis (ON) is a disease that ultimately results in bone collapse. We investigated the correlation between SNPs and osteonecrosis. In this study, 109 patients with systematic lupus erythematosus (SLE) (21 with and 88 without osteonecrosis) were collected for genotype analysis of 7 genes including Introduction
Methods
Osteonecrosis (ON) is one of the most debilitating skeletal disorders. Most patients with ON of the femoral head eventually require surgery, usually total hip arthroplasty, within a few years of disease onset. Previous reports have shown that alendronate reduces osteoclastic activity and reduces the incidence of femoral head collapse in osteonecrotic hips. A randomized study to examine the ability of alendronate to delay or prevent femoral head collapse was performed. From June 2005 to December 2006, sixty four patients were enrolled and randomly assigned to alendronate or placebo. Five patients were excluded from the analysis because of their failure to adhere to the study protocol. Disease progression was evaluated using radiographs and magnetic resonance imaging (MRI).Introduction
Methods
A longer stay in the hospital after primary total hip replacement is consistent with an increased morbidity and slower recovery for patients. In addition, it is among the more costly aspects of a total joint replacement. A process, which reduces the length of stay following this procedure and synchronically maintains the high standards of safe care would certainly improve the clinical practice and provide financial benefits. Our objective was to evaluate the efficiency of a holistic perioperative, accelerated recovery programme following this procedure and in particular to assess its impact in the shot term patient’s recovery, morbidity, complications, readmission rate and cost savings for the NHS. Eighty-nine patients participated in our rapid recovery programme, which is a comprehensive approach to patient care, combining individual pre-operative patient education, pain management, infection control, continuous nursing and medical staff motivation as well as intensive physiotherapy in the ward and the community. Forty-eight male and 41 female patients with an average age of 69 (range-50 to 87) underwent a total hip replacement in an NHS District General Hospital. The average BMI was 28 (range-18 to 39) and the average ASA 2.3 (range-1 to 4). The procedure was performed by 3 different surgeons using the same operative standards. A standardised post-operative protocol was followed and the patients were discharged when they were medically fit and had achieved the ward physiotherapy requirements. They were then daily followed up by a community orthopaedic rehabilitation team in patient’s own environment as long as it was required. The average length of stay was reduced from 7.8 days to 5. There was no increase in complications–or readmissions rate while there were significant cost savings. The waiting list for this surgery was reduced and the patient’s satisfaction was high. The rapid recovery programme for primary total hip replacement surgeries has been proved to be an efficient method of reducing the length of stay in hospital and consequently the financial costs while it ensures the safe and effective peri-operative management of patients.
It is established good practice that joint replacements should have regular follow-up and for the past seven years at the North Hampshire Hospital a local joint register has been used for this purpose and we compare this with results of the Swedish and UK national registries. Since March 1999, all primary and revision knee arthroplasties performed at North Hampshire Hospital, Basingstoke have been prospectively recorded onto a database set up by one of the senior authors (JMB). Data from patients entered in the first six years of the register were analysed. All patients have at least one year clinical and radiological review then a minimum of yearly postal follow-up. As of 31/12/2006, 2854 knee replacement procedures had been performed under the care of 13 consultants. OA was the most common diagnosis in over 75% of knees. 5.2% of patients had died and 4.6% were lost to follow-up. Our revision burden was 3.5% and we had a revision rate of 1.4% for primary total knee replacements. Audit of data for revisions and patello-femoral replacements has enabled us to change our practices. Mean length of stay was 7.2 days for primary total knee arthroplasty versus 4.0 days for unicompartmental knee arthroplasty and 5.4 days for patellofemoral replacement and mean flexion at discharge was 88.4, 93.7 and 88.7 degrees respectively. WOMAC and Oxford scores at 2 years had improved from a mean of 52 and 21 pre-operatively to 74 and 39 respectively for primary total knee arthroplasty. Our costs are estimated at approximately £35 per patient for their lifetime on the register. Compared to other registries:
Our dataset is more complete and comprehensive Our costs are less All patients have a unique identifier (at least 19% of UKNJR data is anonymous) Our audit loops have been closed
Stress shielding (i.e. reduction in bone strains) in the distal ulna is commonly noted following ulnar head replacement arthroplasty. Optimal design parameters for distal ulnar implants, including the length of the stem, are currently unknown. The purpose of this study was to investigate the effect of stem length on bone strains along the length of the ulna. Strain gauges were applied to each of eight cadaveric ulnae to measure bending loads at six locations along each ulna’s length (approximately 1.5, 2.5, 4.0, 6.0, 8.0, and 13.0cm from the ulnar head). The proximal portion of each bone was secured in a custom-designed jig. A materials testing machine applied loads (5–30N) to the ulnar head while native strains were recorded. The ulnar head was removed and the loading procedure repeated for cemented stainless steel stems 3 and 7cm in length, according to a previously reported technique (Austman et al, CORS 2006). Other stem lengths between 3 and 7cm were tested in 0.5cm intervals with a 20N load applied only. Data were analyzed using a two-way repeated measures ANOVA (á=0.05). In general, distal bone strains increased as stem length decreased (e.g. average microstrains at the second distal-most gauges: 138±13 (7cm), 147±15 (6cm), 159±21 (5cm), 186±40 (4cm), 235±43 (3cm)). The native strains were different from all stem lengths for the four distal-most gauges (p<
0.05). No differences were found between any stem length and the native bone at the two proximal-most gauges. The 3cm stem replicated the native strains more closely than the 7cm, over all applied loads (e.g. average microstrains at the third gauge level for a 25N load: 357±59 (native), 396±74 (3cm), 257±34 (7cm)). No stem length tested matched the native strains at all gauge locations. The 3cm stem results were closer to the native strains than the 7cm stem for all loads at gauges overtop of the stem. Overall, the 3cm stem produced the highest strains, and thus would likely result in less distal ulnar bone resorption after implantation. These results suggest that shorter (approximately 3cm) stems should be considered for distal ulnar implants to potentially reduce stress shielding, although this must be balanced by adequate stem length for fixation.
All patients were evaluated prior to surgery. The patients with coexisting inflammatory disease or peri-prosthetic fracture were also evaluated. A hip was diagnosed as infected on the basis of positive intra operative microbiology samples three or more out of five and or histological evidence.
To determine the ten-year survivorship of the Original M E Muller Straight Stem Total Hip Replacement System with emphasis on the longevity of the femoral component in accordance with guidelines published by the National Institute of Clinical Excellence, 266 consecutive hip arthroplasties using the above prosthesis were performed by the senior author between 1983 and 1992. 24 patients were lost to follow-up. Of the remaining 242 patients 80 were male and 162 female. The mean age was 67.49 years. The diagnosis for the majority of patients was osteoarthritis of the hip joint. Pre-operative planning was carried out and the patients were scored using Charnley’s modification of the d’ Aubigne and Postel numerical grading system A mono-bloc stem with a 32-millimeter head used via the trans gluteal approach recommended by Muller. Following discharge serial follow-up consisted of both clinical and radiological evaluation. The data was prospectively stored on a Microsoft access database. The survival of the prosthesis using revision for aseptic loosening as an end-point was calculated by actuarial analysis. 135 patients attended their ten-year follow-up. 97% of patients had good to excellent pain relief and improvement in movement of the joint following surgery. 38% had good to excellent mobility with the remaining having restricted mobility due to associated co-morbid factors. Only in 3% of patients was mobility restricted as a result of the arthroplasty. 7 revisions were carried out for aseptic loosening, all as a result of failure of the acetabular component. The cumulative survival for this hip replacement system was 95.9% and that for the femoral component was 100% at 10 years. The Muller Straight Stem femoral component is based on a press-fit concept and gives predictable long-term results when recommended surgical technique is followed. This series confirms the reliability of the stem design and satisfies the NICE guidelines.
This in-vitro study was conducted to determine the effect of rotator cuff tears on joint kinematics. A shoulder simulator produced unconstrained active abduction of the humerus. Three sequential 1cm lesions were created, the first two in the supraspinatus tendon and the third in the subscapularis tendon. The plane of abduction moved posteriorly and became more abnormal throughout abduction as the size of the tear increased. It is concluded that in order to generate the same motions achieved by the intact joint other muscle groups must be employed, inevitably resulting in altered joint loading. This in-vitro study was conducted to determine the effect of simulated progressive tears of the rotator cuff on active glenohumeral joint kinematics. Five cadaveric shoulders were tested using a shoulder simulator designed to produce unconstrained active motion of the humerus. Forces were applied to simulate loading of the supraspinatus, subscapularis, infraspinatus/teres minor, anterior, middle, and posterior deltoid muscles based upon variable ratios of electromyographic data and average physiological cross-sectional area of the muscles. Three sequential 1cm lesions were created, the first two in the supraspinatus tendon and the third in the subscapularis tendon. Simulated active glenohumeral abduction was performed following the creation of each lesion. Five successive tests were performed to quantify repeatability. The plane of abduction moved posteriorly and became more abnormal throughout abduction as the size of the lesion increased (p=0.01) (Figure 1). In order to generate the same motions achieved with an intact rotator cuff other muscle groups must be employed, inevitably resulting in altered joint loading. A better understanding of the effects that rotator cuff tears have on the kinematics of the glenohumeral joint may result in the development of innovative rehabilitation strategies to compensate for this change in muscle balance and improve the clinical outcomes. Please contact author for diagram and/or graph.
Among two hundred and twenty hemivertebrae in our files we performed over a period of eighteen years sixty nine hemivertebrae (HV) excision. Only H.V. with evidence of curve progression were operated on. The technique was a one stage anterior and posterior approach plus convex anterior and posterior arthrodesis plus convex posterior instrumentation using in the more recents cases a baby C.D. Material: The location of the H.V. was thoraco-lumbar in twenty five cases, lumbar in twenty nine and lumbo-sacral in fifteen. Thirty two free, thirty six hemifused and only one fused H.V. were operated on. The sex ratio was 35 males and 34 females. Associarted malformations were numerous. If the rate of visceral associated malformations is rather the same whatever was the location of the H.V. ( 40% ) the number of associated spine malformations decrease from cranial to caudal ( 60% for thoraco-lumbar H.V. versus 13 % for lumbo-sacral H.V.) The mean age at surgery was 3Y 3M ( 1Y- 9Y) with a mean F.U. of 5Y ( 6M-18Y) for the 25 thoraco-lumbar H.V., respectively 3Y3M ( 1Y- 8Y3M) for the mean age at surgery and 5Y ( 1M-17Y5M) for the average F.U.for the 29 lumbar H.V. and 5Y1M (1M-10Y4M) for surgery and 7Y (1M-18Y3M) for F.U. for the remaining 15 lumbo-sacral H.V. Results: 8 complications were encountered: 4 hardware failures, 1 sepsis, 1 transient paresthesia of the tibial nerve, 1 partial loss of power in the tibialis anterior and 1 valgus deformity following fibular bone grafting. For the 25 thoraco-lumbar H.V. the average scoliosis Cobb angle pre operatively was 38° ( 18°/ 75°) and at F.U. 24° ( 0°/ 76°) . The mean kyphosis Cobb angle was 24° ( -20°/ 54°) pre operatively and 25° (-16°/60°) at F.U. For the 29 lumbar H.V. the mean scoliosis Cobb angle was 35° (16°/58°) pre operatively and 10° (0°/38°) at F.U.The average kyphosis Cobb angle was -2°( -45°/20°) pre operatively and -6° (-42°/22°) at F.U. For the remaining 15 lumbo-sacral H.V. the average scoliosis Cobb angle was 30° (18°/40°) pre operatively and 13° (2°/32°) at F.U. The mean kyphosis Cobb angle was -22°(-54°/0°) pre operatively and -25°(-64°/-8°) at F.U. H.V. excision is in our opinion the best procedure to treat thoraco-lumbar,lumbar and lumbo-sacral H.V. as far as there is evidence of curve progression. The appropriate age to perform this kind of surgery is before three years of age.
We wished to see if Orthopaedic Surgeons are using the current evidence with regard to the use of drains in knee arthroplasty. A questionnaire was faxed to UK members of BASK. We had a 71. 7% response rate (160 responses out of 223). For primary TKR, 89. 5% always use a drain. 42. 1% removed their drains at between 24 and 48 hours. The commonest reason for using drains was to prevent haematoma or haemarthrosis development. The study suggests that the majority of BASK members do not practice evidence based medicine with regard to the use of knee drains.
Primary TKR: Always 136(89.5%); Sometimes 13(8.5%), Never 3(2.0%). Revision TKR: Always 141(94.6%); Sometimes 3 (2.0%); Never 5(3.4%); Not applicable 3. Unicompartmental: Always 66(57.9%); Sometimes 28(24.6%); Never 20(17.5%); Not applicable 3.1. Hours drain removed at: <
24 hours 77(50.7%); 24–48 hours 64(42.1%); >
48 hours 4(2.6%); No answer 7(4.6%). Rationale for drain use: Prevent wound haematoma/haemarthrosis 74; personal reasons 27; to allow retransfusion 20; evidence based 12; despite evidence 5. 29.6% of the responders are currently using cell salvage drains, and a further 7.9% are keen to start using cell salvage drains when the circumstances in their hospitals change to allow them to do so.
The work of Sloof, Ling and Gie has established allografting as a modern technique in revision total hip arthroplasty. The use of allograft enhances the local bone stock and provides a secure fixation for cemented components. Its association with the problem of heterotopic ossification has not been previously considered. The records and x-rays of 114 patients after revision hip surgery were reviewed. All had been operated upon by three Consultant Orthopaedic Surgeons using standard techniques. 35 patients had undergone revision with impaction allografting of both the femur and acetabulum, 29 had allografting of the femur only, 18 of the acetabulum alone and the final 32 patients (acting as controls) had cemented revision arthroplasty without impaction allografting. Fresh frozen allograft was used in all cases and prepared using a bone mill. No patient was given radiation or Indomethacin after their revision surgery, even if they had pre-existing heterotopic ossification. The immediate pre-operative x-rays and x-rays at least a year post-revision were assessed independently by a musculoskeletal radiologist. He was blinded to the type of revision procedure and graded the heterotopic ossification according to the Brooker Classification. Our results report the incidence of heterotopic ossification after revision hip arthroplasty with fresh frozen allograft when compared with cemented revision arthroplasty from our unit and other studies.