In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimise exposure on the wards. In order to maintain throughput of elective cases, our hospital was forced to convert as many cases as possible to same day procedures rather than overnight admission. In this retrospective analysis we review the cases performed as same day arthroplasty surgeries compared to the same period 12 months previous.

We conducted a retrospective analysis of patients undergoing total hip and knee arthroplasties in a three month period between October and December in 2019 and again in 2020, in the middle of the SARS-CoV-2 pandemic. Patient demographics, number of out-patient primary arthroplasty cases, length of stay for admissions, 30-day readmission and complications were collated.

In total, 428 patient charts were reviewed for the months of October-December of 2019 (n=195) and 2020 (n=233). Of those, total hip arthroplasties comprised 60% and 58.8% for 2019 and 2020, respectively. Demographic data was comparable with no statistical difference for age, gender contralateral joint replacement or BMI. ASA grade I was more highly prevalent in the 2020 cohort (5.1x increase, n=13 vs n=1). Degenerative disc disease and fibromyalgia were less significantly prevalent in the 2020 cohort. There was a significant increase in same day discharges for non-DAA THAs (2x increase) and TKA (10x increase), with a reciprocal decrease in next day discharges. There were significantly fewer reported superficial wound infections in 2020 (5.6% vs 1.7%) and no significant differences in readmissions or emergency department visits (3.1% vs 3.0%).

The SARS-CoV-2 pandemic meant that hospitals and patients were hopeful to minimise the exposure to the wards and to not put strain on the already taxed in-patient beds. With few positives during the Coronavirus crisis, the pandemic was the catalyst to speed up the outpatient arthroplasty program that has resulted in our institution being more efficient and with no increase in readmissions or early complications.

Aims

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimize exposure on wards. In order to maintain throughput of elective cases, our hospital (St Michaels Hospital, Toronto, Canada) was forced to convert as many cases as possible to same-day procedures rather than overnight admission. In this retrospective analysis, we review the cases performed as same-day arthroplasty surgeries compared to the same period in the previous 12 months.

Aims

While preoperative bloodwork is routinely ordered, its value in determining which patients are at risk of postoperative readmission following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is unclear. The objective of this study was to determine which routinely ordered preoperative blood markers have the strongest association with acute hospital readmission for patients undergoing elective TKA and THA.

Aims

The rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA.

Over 300,000 total hip arthroplasties (THA) are performed annually in the USA. Surgical Site Infections (SSI) are one of the most common complications and are associated with increased morbidity, mortality and cost. Risk factors for SSI include obesity, diabetes and smoking, but few studies have reported on the predictive value of pre-operative blood markers for SSI. The purpose of this study was to create a clinical prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of THA based on commonly ordered pre-operative lab markers and using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

All adult patients undergoing an elective unilateral THA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was used to determine coefficients, with manual stepwise reduction. Receiver Operating Characteristic (ROC) curves were also graphed. The SSI prediction model included the following covariates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphate, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. Since the data met logistic assumption requirements, bootstrap estimation was used to measure internal validity. The area under the ROC curve for final derivations along with McFadden's R-squared were utilized to compare prediction models.

A total of 130,619 patients were included with the median age of patients at time of THA was 67 years (mean=66.6+11.6 years) with 44.8% (n=58,757) being male. A total of 1,561 (1.20%) patients had a superficial or deep SSI (overall SSI). Of all SSI, 45.1% (n=704) had a deep SSI and 55.4% (n=865) had a superficial SSI. The incidence of SSI occurring annually decreased from 1.44% in 2011 to 1.16% in 2016. Area under the ROC curve for the SSI prediction model was 0.79 and 0.78 for deep and superficial SSI, respectively and 0.71 for overall SSI. CHF had the largest effect size (Odds Ratio(OR)=2.88, 95% Confidence Interval (95%CI): 1.56 – 5.32) for overall SSI risk. Albumin (OR=0.44, 95% CI: 0.37 – 0.52, OR=0.31, 95% CI: 0.25 – 0.39, OR=0.48, 95% CI: 0.41 – 0.58) and sodium (OR=0.95, 95% CI: 0.93 – 0.97, OR=0.94, 95% CI: 0.91 – 0.97, OR=0.95, 95% CI: 0.93 – 0.98) levels were consistently significant in all clinical prediction models for superficial, deep and overall SSI, respectively. In terms of pre-operative blood markers, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI.

In this large NSQIP database study, we were able to create an SSI prediction model and identify risk factors for predicting acute superficial, deep and overall SSI after THA. To our knowledge, this is the first clinical model whereby pre-operative hyponatremia (in addition to hypoalbuminemia) levels have been predictive of SSI after THA. Although the model remains without external validation, it is a vital starting point for developing a risk prediction model for SSI and can help physicians mitigate risk factors for acute SSI post THA.

Distracted driving is now the number one cause of death among teenagers in the United States of America according to the National Highway Traffic Safety Administration. However, the risks and consequences of driving while distracted spans all ages, gender, and ethnicity. The Distractions on the Road: Injury eValuation in Surgery And FracturE Clinics (DRIVSAFE) Study aimed to examine the prevalence of distracted driving among patients attending hospital-based orthopaedic surgery fracture clinics. We further aimed to explore factors associated with distracted driving.

In a large, multi-center prospective observational study, we recruited 1378 adult patients with injuries treated across four clinics (Hamilton, Ontario, Toronto, Ontario, Calgary, Alberta, Halifax, Nova Scotia) across Canada. Eligible patients included those who held a valid driver's license and were able to communicate and understand written english. Patients were administered questions about distracted driving. Data were analyzed with descriptive statistics.

Patients average age was 45.8 years old (range 16 – 87), 54.3% male, and 44.6% female (1.1% not disclosed). Of 1361 patients, 1358 self-reported distracted driving (99.8%). Common sources of distractions included talking to passengers (98.7%), outer-vehicle distractions (95.5%), eating/drinking (90.4%), music listening/adjusting the radio (97.6%/93.8%), singing (83.2%), accepting phone calls (65.6%) and daydreaming (61.2%). Seventy-nine patients (6.3%), reported having been stopped by police for using a handheld device in the past. Among 113 drivers who disclosed the cause of their injury as a motor vehicle crash (MVC), 20 of them (17%) acknowledged being distracted at the time of the crash. Of the participants surveyed, 729 reported that during their lifetime they had been the driver in a MVC, with 226 (31.1%) acknowledging they were distracted at the time of the crash.

Approximately, 1 in 6 participants in this study had a MVC where they reported to be distracted. Despite the overwhelming knowledge that distracted driving is dangerous and the recognition by participants that it can be dangerous, a staggering amount of drivers engage in distracted driving on a fairly routine basis. This study demonstrates an ongoing need for research and driver education to reduce distracted driving and its devastating consequences.

Total knee arthroplasty (TKA) is the most commonly performed elective orthopaedic procedure. With an increasingly aging population, the number of TKAs performed is expected to be ∼2,900 per 100,000 by 2050. Surgical Site Infections (SSI) after TKA can have significant morbidity and mortality. The purpose of this study was to construct a risk prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of a TKA based on commonly ordered pre-operative blood markers and using audited administrative data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

All adult patients undergoing an elective unilateral TKA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was conducted to estimate coefficients, with manual stepwise reduction to construct models. Bootstrap estimation was administered to measure internal validity. The SSI prediction model included the following co-variates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphatase, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. To compare clinical models, areas under the receiver operating characteristic (ROC) curves and McFadden's R-squared values were reported.

The total number of patients undergoing TKA were 210,524 with a median age of 67 years (mean age of 66.6 + 9.6 years) and the majority being females (61.9%, N=130,314). A total of 1,674 patients (0.8%) had a SSI within 30 days of the index TKA, of which N=546 patients (33.2%) had a deep SSI and N=1,128 patients (67.4%) had a superficial SSI. The annual incidence rate of overall SSI decreased from 1.60% in 2011 to 0.68% in 2016. The final risk prediction model for SSI contained, smoking (OR=1.69, 95% CI: 1.31 – 2.18), previous/current steroid use (OR=1.66, 95% CI: 1.23 – 2.23), as well as the pre-operative lab markers, albumin (OR=0.46, 95% CI: 0.37 – 0.56), blood urea nitrogen (BUN, OR=1.01, 95% CI: 1 – 1.02), international normalized ratio (INR, OR=1.22, 95% CI:1.05 – 1.41), and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98;). Area under the ROC curve for the final model of overall SSI was 0.64. Models for deep and superficial SSI had ROC areas of 0.68 and 0.63, respectively. Albumin (OR=0.46, 95% CI: 0.37 – 0.56, OR=0.33, 95% CI: 0.27 – 0.40, OR=0.75, 95% CI: 0.59 – 0.95) and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98, OR=0.96, 95% CI: 0.93 – 0.99, OR=0.97, 95% CI: 0.96 – 0.99) levels were consistently significant in all prediction models for superficial, deep and overall SSI, respectively. Overall, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI.

To our knowledge, this is the first prediction model for acute SSI post TKA whereby hyponatremia (and hypoalbuminemia) are predictive of SSI. This prediction model can help fill an important gap for predicting risk factors for SSI after TKA and can help physicians better optimize patients prior to TKA.

The purpose of this investigation is to assess the rate of wear the effect once the “bedding in period”/ poly creep had been eliminated. Creep is the visco-elastic deformation that polyethylene exhibits in the first 6–12 weeks. We also assessed the wear pattern of four different bearing couples in total hip arthroplasty (THA): cobalt-chrome (CoCr) versus oxidized zirconium (OxZir) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) versus highly-crosslinked polyethylene (XLPE) acetabular liners.

This was a randomized control study involving 92 patients undergoing THA. They were randomized to one of four bearing couples: (1) CoCr/UHMWPE (n= 23), (2) OxZir/UHMWPE (n=21), (3) CoCr/XLPE (n=24), (4) OxZir/XLPE (n=24). Patients underwent a posterior approach from one of three surgeons involved in the study. All patients received a porous-coated cementless acetabular shell and a cylindrical proximally coated stem with 28 mm femoral heads. Each patient was reviewed clinically and radiographically at six weeks, three and 12 months, two, five and 10 years after surgery. Standardized anteroposterior and lateral radiographs were taken. All polyethylene wear was measured by an independent blinded reviewer. Linear and volumetric wear rates were measured on radiographs using a validated computer software (Polyware Rev. 5). Creep was defined as the wear at 6 or 12 weeks, depending on if there was a more than 10% difference between both measurements. If a greater than 10% difference occurred than the later period's wear would be defined as creep.

72 hips were included in analysis after exclusion of seven revisions, three deaths and 10 losses to follow-up. The annual linear wear rates (in mm/y) at 10 years were (1) 0.249, (2) 0.250, (3) 0.074 and (4) 0.050. After adjusting for creep these rates become were (1) 0.181, (2) 0.142, (3) 0.040 and (4) 0.023. There is statistical differences between raw and adjusted linear wear rates for all bearing couples. The percentage of the radiographically measured wear at 10 years due to creep is (1) 30% (2) 44%, (3) 58.5% and (4) 51.5% with significant differences in couples with XLPE versus those with UHMWPE. There was no significant correlation between age, gender, cup size, tilt, planar anteversion and the linear or volumetric wear rates.

The linear wear rate of both UHMWPE and XLPE are even lower thxdsxzan previously described when creep is factored out. XLPE has again demonstrated far superior linear wear rates at 10 years than UHMWPE. There were no significant differences in wear rate at 10 years between CoCr and OxZir, this may be due to an underpowered study. XLPE exhibits proportionally more creep than UHMWPE within the first 6–12 weeks and accounts for more of the total wear at 10 years as measured radiographically at the end period.

A randomized trial was designed to compare the outcome of ceramic-on-ceramic with ceramic on conventional polyethylene. These patients have been followed for 15 years.

58 hips in 57 patients under 60 years of age were randomized into one of two groups. Patients were blinded to the type of hip they received. Both groups of patients were treated routinely with prophylactic peri-operative antibiotics and low molecular weight Heparin. All patients were seen at six weeks, three months and annually after surgery. Clinical and radiologic assessment was carried out at each visit.

Fifty-eight hips were available for analysis, 28 in the CoP group and 29 patients in the CoC group. Mean age of both groups was less than 45 years.

There were seven revisions (16%) among the 58 patients enrolled in the study. In the CoP group four patients underwent revision with head and liner exchange for eccentric polyethylene wear 16 years post-implantation. In the CoC group one patient had a cup revision at 15 years for acute aseptic instability of the acetabulum; two additional patients in the CoC group had femoral head exchange, one for fracture and one for trunnion corrosion. Both occurred 14 years after the index surgery.

Functional outcome scores showed no difference between the two groups at 15 years. Radiographically there was a statistically difference in wear between the two groups.

This study demonstrates that both ceramic-on-ceramic and ceramic-on-polyethylene produce satisfactory functional results with low revision rates in young patients.

Several implants have a proven track record of durability and function in patients over many years. As manufacturers' patents expire it is understandable that cheaper generic copies would be considered. There is currently no established, independent method of determining design equivalence between generic and branded orthopaedic implants.

We acquired 10 boxed, as manufactured components consisting of the generic OptiStem XTR model (n=5) and branded Exeter (n=5) femoral stems. Two examiners were blinded to the implant design and independently measured the mass, volume, trunnion surface topography, roughness, trunnion cone angle, CCD angle and femoral offset using peer-reviewed methods. We then compared the stems using these parameters.

We found that the OptiStems (1) were lighter (p<0.001) (2) had a rougher trunnion surface (p<0.001) with a greater spacing and depth of the machined threads (p<0.001), (3) had greater trunnion cone angles (p=0.007) and (4) a smaller radius at the top of the trunnion (p=0.007). There was no difference for stem volume (p=0.643), CCD angle (p=0.788) or offset (p=0.993).

This study is the first independent investigation of the equivalence of a generic orthopaedic implant to its branded design. We found a clear difference in trunnion roughness, trunnion cone angle and radius, and implant mass when comparing the two generic and branded stem designs. All implants require standard regulatory processes to be followed. It does not appear feasible that generic implants can be manufactured to predictability guarantee the same performance as generic drugs.

We found a number of physical differences between the generic and branded implants. Whilst both designs are likely to work in clinical practice, they are different.

Aims

The aim of this study was to compare the design of the generic OptiStem XTR femoral stem with the established Exeter femoral stem.

In this review, we present the data of one of the largest non-designer, mid- to long-term follow ups of the AGC.

We present a total of 1538 AGC knees during a 15 year period, of which 902 were followed up by postal or telephone questionnaire focused on Oxford Knee Scores, Visual analogues of function and pain and survival analyses performed. Mean length of follow up was 10.4 years.

85.7% of patients had an Oxford knee score of between 0 and 40, with 71.2% scoring between 0–30.

65.6% of patients responded with a Visual Analogue Score (VAS) of 0 or 1 at rest (minimum pain 0) and 53.9% reporting VA scores of 0 or 1 while walking.

87.5% of patients reported Excellent or good functional reports at final follow up and 90.3% reporting excellent or good pain control compared to per-operative levels.

Survival analysis confirms excellent survivorship.

This large cohort and multi-surgeon trial reproduces the excellent results as demonstrated by the designer centre (Ritter et al.). Mid to long term outcome sows excellent function and analgesia. Complication rates are low and the necessity for revision remains low.

We systematically reviewed the published literature on the complications of closing wedge high tibial osteotomy for the treatment of unicompartmental osteoarthritis of the knee. Publications were identified using the Cochrane Library, MEDLINE, EMBASE and CINAHL databases up to February 2012. We assessed randomised (RCTs), controlled group clinical (CCTs) trials, case series in publications associated with closing wedge osteotomy of the tibia in patients with osteoarthritis of the knee and finally a Cochrane review. Many of these trials included comparative studies (opening wedge versus closing wedge) and there was heterogeneity in the studies that prevented pooling of the results.

Accurate documentation of operative findings is a fundamentally important part of any procedure and forms part of the Royal College of Surgeons of England's guidelines to good care, especially to “ensure that there are legible operative notes (typed if possible) for every operative procedure.” However, many hospitals fall short of this guideline when it comes to arthroscopic procedures because of the difficulty in reproducing visually representative and easy-to-understand images. There is an inability to properly record and archive findings of arthroscopic procedures. We, along with the British Orthopaedic Association, have developed an interactive, free Web-based operative note template that allows the surgeon to draw findings on diagrams of the joints commonly undergoing arthroscopy, type the findings, and then print as many copies as required. The use of the forms has allowed for quicker, easier, and more accurate documentation of arthroscopic procedures. The forms can then be saved to a database and used as a research tool.

Purpose of Study

In this review, we present the data of one of the largest non-designer, mid- to long-term follow-ups of the AGC carried out by surgeons of differing grades and sub-specialty.

We review all litigation brought against English Orthopaedic departments involving children under the age of 16 and attempt to highlight areas where they might be avoided. The NHSLA (the National Health Service Litigation Authority) is a special Health Authority responsible for handling negligence claims made against NHS bodies in England. In addition to dealing with claims when they arise, there is an active risk management programme to help raise standards of care in the NHS and hence reduce the number of incidents leading to claims. By analysing the claims data, we have had the opportunity to see trends for which Trusts have litigation brought against them, how much this costs the Health Service and most importantly how this information can aid in clinical practice.

Between 1995 until 2005/06 there were 408 cases involving orthopaedics in England that had reached a conclusion. Of those considered in our study (341), by far the most common broad category for litigation is missed or delayed diagnosis of a condition 179 cases (57% of all litigation cases) with 44% (80 cases) of those being upper limb traumatic injuries. Humeral supracondylar fractures and elbow injuries constitute 24% (44 cases) of all missed diagnoses with each having an average total payout of £27,998. Missed or poorly managed developmental disorders of the hip (DDH or SUFE) also have large total payouts. Other common causes for litigation are intra-operative errors with poor results/complications for fixation of humeral supracondylar fractures again being the most common. Complications of plasters also represent 7.3% of all claims, all with high total payouts.

In assessing these trends, we suggest highlighting the potential for error during training of juniors and taking extra care during clinical practice. There are also implications identified for the planned provision of Orthopaedic care of children.

Every country has its own criteria for consent. In most, a written consent form is used to reflect patient understanding and permision for the procedure to happen.

While oral consent has as much legal sway as the written consent form, the presence of a signature acts as proof of discussion. All European hospitals should have a 100% compliance with patient’s signing consent forms, but their completion is often incomplete and inaccurate, have errors of omission and have lead to litigation, poor patient understanding and recall.

We (along witht the BOA) introduce an computer programme of procedure specific orthopaedic consent forms. They have been created for most common elective and trauma operations. The forms follow the UK Department of Health guidelines on consent and contain a brief explanation of the procedure, offer alternative therapies/consequences of not having the procedure (where appropriate), the serious risks and commonly occurring complications. They are written in layman’s English (aimed at a reading age of 14 years). Preliminary trials have also shown the time taken to print and complete a pre-designed form is much less than that of the current handwritten form, reducing errors of omission whilst still allowing discussion with the patient.

The forms are currently available as word documents from an easily navigable website. With a view towards European usage, the forms can be easily translated to other languages at minimal cost.

With support from the British Orthopaedic Association (BOA), the BOA medico-legal committee, the specialist societies and consultant users (via the website) we hope that the project will continue to evolve with a greater selection of procedural consent forms becoming available.

It is believed, from the evidence available, that this approach should decrease the incidence of patient misunderstanding, and the potential risk of successful litigation, while encouraging better communication between patients and surgeons.

The aim of this study was to discover if the ulnar styloid is sufficiently consistent in size, shape and position relative to other bony features of the ulna to be used as a reference in pre-operative planning of fixation of broken bones.

The comparison of size and shape (together known as form) between bones has recently been facilitated thanks to the advance of technologies designed to allow the comparison of the form of structures using anatomical landmarks.

This new class of methods is collectively known as geometric morphometrics. It eliminates the differences in location and rotation of landmark through registration that minimises the sum of squared deviations from each other after scaling. This is Procrustes registration. The residual size and shape information is amenable to statistical analysis. In the present application, the registered Procrustes landmarks are used to compute a mean (reference) shape. The individuals are then compared to this mean/ reference shape. Using principal components analysis (PCA) variations in shape are not only identi-fied, but also quantified. The identification of patterns of deviation from the mean shape is considerably enhanced through the use of 3-D visualistaions of the shape variations represented by the space of the PCA.

These analyses indicate that the ulnar styloid is suf-ficiently consistent in location to other anatomical landmarks that it could be used as a radiographic marker in preoperative planning.

More importantly, the analysis of this study indicates that the methods of geometric morphometrics are widely applicable to the analysis of 3-D variations in morphology facilitating the analysis and comparison of radiographs. A useful future application will be in the development of 3-D reference morphologies that will allow the surgeon to compare and contrast the morphology of a radiograph of a badly broken (comminuted) bone to a standard one. Eventually computer might assist the surgeon by geometrically and visually showing how and by how much the bone needs reduction. Similarly, applications to the the virtual comparison of diseased and healthy bones might allow quantative and visual comparisons that could aid diagnosis and planning.

Our study aims were to establish correlations between the incidence of patellofemoral pain and clinical, functional and radiographic outcomes in Total Knee Arthroplasty (TKR), using the Duracon prosthesis without patella resurfacing.

A consecutive cohort of 52 patients (71 knees) were reviewed at a special follow up clinic at a mean of 29 months. All operations were carried out by a single surgeon or under his direct supervision using a standard procedure. Patients were evaluated clinically and asked directly if they had anterior knee pain. American Knee Society Scores (AKSS) and knee alignment were assessed and patients completed SF-12 and WOMAC questionnaires. Standardised 45 degree skyline and standing lateral radiographs were taken and assessed by a single blinded observer, and patella tilt and displacement measured using Gomes’ method, and patella height measured using the Insall-Salvati ratio. Knees with patellofemoral pain underwent triple phase bone scintigraphy using Technetium 99m-MDP with vascular, blood pool and static (3 hour) imaging.

Significant patellofemoral pain was identified in 8 knees (11%), in 6 patients. This group had a reduced mean AKSS compared to knees without patellofemoral pain, although 50% still had a good to excellent outcome as judged by the AKSS. Only 2 knees with patellofemoral pain had abnormal alignment (2 and 12 degrees valgus). The mean SF-12 and WOMAC scores did not differ significantly between knees with patellofemoral pain and those without. Patella tilt and displacement were a common finding in this cohort, and could be as great as 17 degrees and 30% respectively without patellofemoral dysfunction. Paradoxically the mean values for these parameters were found to be reduced in knees with patellofemoral pain. Patella height did not substantially vary between knees with patellofemoral pain and those without. Bone scintigraphy of 7 of the knees with patellofemoral pain revealed a spectrum of activity from complete normality (3 knees) to tricompartmental increase in activity (2 knees). Increased activity localised to the patellofemoral articulation was evident in 2 knees.

We conclude that despite favourable overall results, the Duracon prosthesis fails to eliminate patellofemoral pain without patella resurfacing. This conflicts with excellent reported results using this anatomic prosthesis with patella resurfacing. The presence of patellofemoral pain correlates well with a poor AKKS, but the role of plain radiography and bone scintigraphy as investigative tools remains unclear.