Background. Patterns of opioid overprescribing following arthroplasty likely developed given that poor pain control can diminish patient satisfaction, delay disposition, and lead to complications. Recently, interventions promoting responsible pain management have been described however most of the existing literature focuses on opioid naive patients. We sought to describe the effect of an educational intervention on prescribing for opioid tolerant patients. Methods. As the start to a quality improvement initiative to reduce opioid overprescribing, a departmental grand rounds was conducted. Prescribing data, for the year before and after this intervention, were retrospectively collected for all opioid tolerant patients undergoing primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA). Opioid prescribing data was standardized to mean morphine equivalents (MME). Segmented time series regression was utilized to estimate the change in opioid prescribing associated with the intervention. Results. A total of 508 opioid tolerant patients underwent TKA and 342 opioid tolerant patients underwent THA at our institution during the study period. The intervention was associated with a statistically significant decrease of 468 mean MME (23%) from 2,062 to 1,594 (P=0.005)in TKA patients and 594 mean MME (28%) from 2,159 to 1,565 (P=0.003) in THA patients. There were no readmissions for pain control during the study period. Conclusions. This study demonstrates an educational intervention is associated with decreased opioid prescribing to opioid tolerant arthroplasty patients. While the effective management of these patients is challenging, surgeon education should be a key focus to optimizing their care. Level of Evidence. Level III, retrospective cohort study. Keywords. Primary Arthroplasty; Opioid Tolerant; Analgesics, Opioid; Practice Patterns, Physicians; Quality Improvement; Pain, Postoperative

Metal-on-metal (MOM) retrieval studies have demonstrated that CoCr bearings used in total hip arthroplasty (THA) and resurfacing (RSA) featured stripe wear damage on heads, likely created by rim impact with CoCr cups. 1-3. Such subluxation damage may release quantities of large CoCr particles that would provoke aggressive 3. rd. -body wear. With RSA, the natural femoral neck reduces the head-neck ratio but avoids risk of metal-to-metal impingement (Fig. 1). 4. For this study, twelve retrieved RSA were compared to 12 THA (Table 1), evaluating, (i) patterns of habitual wear, (ii) stripe-wear damage and (iii) 3. rd. -body abrasive scratches. Considering RSA have head/neck ratios much lower than large-diameter THA, any impingement damage should be uniquely positioned on the heads. Twelve RSA and THA retrievals were selected with respect to similar diameter range and vendors with follow-up ranging typically 1–6 years (Table 1). Patterns of habitual wear were mapped to determine position in vivo. Stripe damage was mapped at three sites: polar, equatorial and basal. Wear patterns were examined using SEM and white light interferometry (WLI). Graphical models characterized the complex geometry of the natural femoral neck in coronal and sagittal planes and provided RSA head-neck ratios. 4. Normal area patterns of habitual wear were similar on RSA and THA bearings. The wear patterns showing cup rim-breakout proved larger for RSA cups than THA. Polar stripes presented in juxtaposition to the polar axis in both RSA and THA (Fig. 1). As anticipated, basal stripes on RSA occurred at steeper cup-impingement angles (CIA) than THA. The micro-topography of stripe damage was similar on both RSA and THA heads. Some scratches were illustrative of 3. rd. -body wear featuring raised lips, punctuated terminuses, and crater-like depressions (Fig. 2). Neck narrowing observed following RSA procedures may be a consequence of impingement and subluxation due to the small head-neck ratios. However, lacking a metal femoral neck, such RSA impingement would not result in metal debris being released. Nevertheless it has been suggested that cup-to-head impingement produced large CoCr particles and also cup “edge wear” as the head orbits the cup rim. 4. Our study showed that impingement had occurred as evidenced by the polar stripes and 3. rd. -body wear by large hard particles as evidenced by the wide scratches with raised lips. We can therefore agree with the prior study, that 2-body and 3rd-body wear mechanisms were present in both RSA and THA retrievals

Fractures of the distal radius are common, and form a considerable proportion of the trauma workload. We conducted a study to examine the patterns of injury and treatment for adult patients presenting with distal radius fractures to a major trauma centre serving an urban population.

We undertook a retrospective cohort study to identify all patients treated at our major trauma centre for a distal radius fracture between 1 June 2018 and 1 May 2021. We reviewed the medical records and imaging for each patient to examine patterns of injury and treatment. We undertook a binomial logistic regression to produce a predictive model for operative fixation or inpatient admission.

Overall, 571 fractures of the distal radius were treated at our centre during the study period. A total of 146 (26%) patients required an inpatient admission, and 385 surgical procedures for fractures of the distal radius were recorded between June 2018 and May 2021. The most common mechanism of injury was a fall from a height of one metre or less. Of the total fractures, 59% (n = 337) were treated nonoperatively, and of those patients treated with surgery, locked anterior-plate fixation was the preferred technique (79%; n = 180).

The epidemiology of distal radius fractures treated at our major trauma centre replicated the classical bimodal distribution described in the literature. Patient age, open fractures, and fracture classification were factors correlated with the decision to treat the fracture operatively. While most fractures were

Metastatic bone disease (MBD) is a significant contributor to diminished quality of life in cancer patients, often leading to pathologic fractures, hypercalcaemia, intractable bone pain, and reduced functional independence. Standard of care management for MBD patients undergoing orthopaedic surgery is multi-disciplinary, includes regular surgical follow-up, case by case assessment for use of bone protective medications, and post-operative radiation therapy to the operative site. The number of patients in southern Alberta receiving standard of care post-operative management is currently unclear. Our aim is to develop a database of all patients in southern Alberta undergoing orthopaedic surgery for MBD and to assess for deficiencies and opportunities to ensure standard of care for this complex patient population.

Patients were identified for database inclusion by a search query of the Alberta Cancer Registry of all patients with a diagnosis of metastatic cancer who underwent surgery for an impending or pathologic fracture in the Calgary, South and Central Alberta Zones. Demographic information, primary cancer history, previous local and systemic treatments, anatomical location of MBD event(s), surgical fixation techniques, and post-operative care details were collected. The rate of standard of care post-operative treatment was evaluated. A comparison of outcomes between tertiary urban centres and rural centres was also completed. Survival was calculated from time of first operation to date of death. Univariate and multivariate analyses were performed to identify the impact of post-operative care variables on survival amongst patients surviving longer than one month.

We identified 402 patients who have undergone surgical treatment for MBD in southern Alberta from 2006-2018. Median age at time of surgery was 66.3 years and 52.7% of patients were female. Breast, lung, prostate, renal cell and multiple myeloma were the most common primary malignancies (n=328, 81.6%). Median post-operative survival was 6.8 months (95%CI: 5.7-8.3). 203 patients (52.5%) were treated with post-operative radiotherapy and 159 patients (50.8%) had post-operative surgical follow-up. Only 39 patients (11.3%) received bone protective agents in the peri-operative period. On multivariate survival analysis, post-operative surgical follow-up was associated with improved survival (p<0.001). Patients were treated at nine hospitals across southern Alberta with most patients treated in an urban center (65.9%). Post-operative survival was significantly longer amongst patients treated in an urban center (9.0 months, 95%CI: 6.9-12.3 versus 4.3 months, 95%CI: 3.4-5.6, p<0.001).

The burden of MBD is significant and increasing. With treatment occurring at multiple provincial sites, there is a need for standardized, primary disease-specific peri- and post-operative protocols to ensure quality and efficacious patient care. To provide evidence informed treatment recommendations, we have developed a database of all patients in southern Alberta undergoing orthopaedic surgery for MBD. Our results demonstrate that many patients were not treated according to post-operative standard of care recommendations. Notably, half of the included patients did not have documented surgical follow-up, post-operative radiation treatment was low and only 11% were actively treated with bone protective agents. This data justifies the need for established surgical MBD care pathways and provides reference data to benchmark prospective QA and QI outcomes in this patient population.

The purpose of this study was to determine whether there have been changes in the complexity of femoral fragility fractures presenting to our Dunedin Orthopaedic Department, New Zealand, over a period of ten years.

Patients over the age of 60 presenting with femoral fragility fractures to Dunedin Hospital in 2009 −10 (335 fractures) were compared with respect to demographic data, incidence rates, fracture classification and treatment details to the period 2018-19 (311 fractures). Pathological and high velocity fractures were excluded.

The gender proportion and average age (83.1 vs 83.0 years) was unchanged. The overall incidence of femoral fractures in people over 60 years in our region fell by 27% (p<0.001). Intracapsular fractures (31 B1 and B2) fell by 29% (p=0.03) and stable trochanteric fractures by 56% (p<0.001). The incidence of unstable trochanteric fractures (31A2 and 31A3) increased by 84.5% from 3.5 to 6.4/10,000 over 60 years (p = 0.04). The proportion of trochanteric fractures treated with an intramedullary (IM) nail increased from 8% to 37% (p <0.001). Fewer intracapsular fractures were treated by internal fixation (p<0.001) and the rate of acute total hip joint replacements increased from 13 to 21% (p=0.07). The incidence of femoral shaft fractures did not change significantly with periprosthetic fractures comprising 70% in both cohorts.

While there has been little difference in the numbers there has been a decrease in the incidence of femoral fragility fractures likely due to the increasing use of bisphosphonates. However, the incidence of unstable trochanteric fractures is increasing. This has led to the increased use of IM nails which are increasingly used for stable fractures as well.

The increasing complexity of femoral fragility fractures is likely to have an impact on implant use, theatre time and cost.

This study aimed to evaluate the month-to-month prevalence of antibiotic dispensation in the 12 months before and after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and to identify factors associated with antibiotic dispensation in the month immediately following the surgical procedure.

In total, 4,115 THAs and TKAs performed between April 2013 and June 2019 from a state-wide arthroplasty referral centre were analysed. A cross-sectional study used data from an institutional arthroplasty registry, which was linked probabilistically to administrative dispensing data from the Australian Pharmaceutical Benefits Scheme. Multivariable logistic regression was carried out to identify patient and surgical risk factors for oral antibiotic dispensation.

Oral antibiotics were dispensed in 18.3% of patients following primary TKA and 12.0% of patients following THA in the 30 days following discharge. During the year after discharge, 66.7% of TKA patients and 58.2% of THA patients were dispensed an antibiotic at some point. Patients with poor preoperative health status were more likely to have antibiotics dispensed in the month following THA or TKA. Older age, undergoing TKA rather than THA, obesity, inflammatory arthritis, and experiencing an in-hospital wound-related or other infectious complications were associated with increased antibiotic dispensation in the 30 days following discharge.

A high rate of antibiotic dispensation in the 30 days following THA and TKA has been observed. Although resource constraints may limit routine wound review for all patients by a surgeon, a select cohort may benefit from timely specialist review postoperatively. Several risk factors identified in this study may aid in identifying appropriate candidates for such changes to follow-up care.

Arthroscopic hip surgery is increasingly common in Australia. Hip arthroscopy is indicated for a range of diagnostic and therapeutic purposes, including labral tears, capsular laxity and femoral-acetabular impingement (FAI). Despite this, previous cohort studies aiming to characterise hip pathology seen on arthroscopic examination are mostly limited to patients with known diagnoses of FAI. Therefore, little is known of the native articular wear patterns encountered in other disease states. Therefore, we aimed to define common osteochondral wear patterns for a cohort of patients managed via hip arthroscopy.

We retrospectively analysed intraoperative data for 1127 patients managed via hip arthroscopy between 2008 and 2013, for either therapeutic or diagnostic purposes. Intraoperative data was categorized by location (A-E as defined by Fontana et al. 2016) and chondral damage (0-4 scale as defined by Beck et al. 2005) with respect to both acetabulum and femoral head.

Data for 1127 patients were included. Location of acetabular chondral pathology was variable with locations C₁ and D₁ representing the most common regions of damage. Labral tears predominated in locations C and D. Femoral chondral pathology was evenly distributed. The degree of femoral chondral injury was predominantly grade 1, whilst acetabular wear was evenly distributed.

Large proportions of wear were observed at the peripheral superior and anterior regions of the lunate surface of the acetabulum in keeping with prior works. However, we observed higher rates of central wear and lower rates of grade 4 acetabular damage extending into superior/posterior zones, in our cohort.

Our work characterises common articular wear patterns encountered at the time of hip arthroscopy. Further inquiry into the natural history of osteochondral lesions is needed to better understand and manage these conditions.

The external fixator is an invaluable device when treating acute complex trauma and in limb reconstruction. It is therefore important to ensure its efficient and safe application to avoid complications. A lot of research has been done to evaluate the factors around external fixator stability, pin site infections and more is still being done to understand pin loosening. The purpose of this study was to evaluate other factors that may contribute in external fixator pin loosening. The aim was to evaluate if the different Schanz pin insertion techniques contribute to pin loosening.

Two tibia diaphyses from two cadavers were each divided into three sections. Three different drilling techniques were repeated in each of the sections. A total of 36 Schanz pins were inserted and a section cut out of the bone in front of the pins was done allowing visual inspection of the pin hole for features of thread stripping. These features were predefined as thread pattern disruption, smoothening and shallow imprint on the cortex.

Evidence of pin thread stripping was seen in all of the pin insertion techniques. The first method where the hole was pre-drilled and pin inserted with the drill showed 100% thread stripping. The second method of pre-drilling and hand insertion showed the least amount with 16.7% of pin stripping noted and 66.7% pin thread stripping was observed when inserting the pin with power without pre-drilling the pilot hole using the third method.

Different pin insertion techniques result in varying amounts of pin thread stripping. The most amount of thread stripping occurs when a Schanz pin is inserted with power after pre-drilling. This finding, although not measured scientifically, supports the current recommendation of pre-drilling and manual insertion of the pin. In future, more scientific measurement are necessary to quantify these findings and assess their clinical significance.

INTRODUCTION

Controversy exists regarding the ability of unicompartmental knee arthroplasty (UKA) to restore native knee kinematics, with some studies suggesting native kinematics are restored in most or all patients after UKA^1–3, while others indicate UKA fails to restore native knee kinematics^4,5. Previous analysis of UKA articular contact kinematics focused on the replaced compartment^2,5, neglecting to assess the effects of the arthroplasty on the contralateral compartment which may provide insight to future pathology such as accelerated degeneration due to overload⁶ or a change in the location of cartilage contact⁷. The purpose of this study was to assess the ability of medial UKA to restore native knee kinematics, contact patterns, and lateral compartment dynamic joint space. We hypothesized that medial UKA restores knee kinematics, compartmental contact patterns, and lateral compartment dynamic joint space.

Introduction

Polymicrobial infections are expected to complicate the treatment of bone and joint infections. Septic nonunions often occur after initial open fractures, which prophylactically receive broad-spectrum antibiotics. However, no data that describes frequencies of polymicrobial infections and pathogens evident in course of the treatment of septic nonunions is published. Therefore, this study aims at investigating the frequency and pathogen types in polymicrobial infections.

Musculoskeletal tumours are relatively rare and as such, they are not well known by the population and by general practicioners. We observed that an important proportion of our patients has seen major delays at diferent stages of their referral pathway. It is well recognised that such delays can cause avoidable loss of function, local and systemic recurrence and increase in health system costs. The main objective of this study was to prospectively assess the referral paterns of our patients to pinpoint the causes of the delays. This should allow the formation of strategies to minimise delas and their impact. The secondary objective was to assess the performance of our centre in comparaison to other centre with the goal of improving quality of care.

Prospective follow up data is available for 457 patient referred to our musculoskeletal oncology team between july 2011 and november 2014. Every patients filled questionnaires on their initial referral patterns. Site specific function and quality of life are evaluated at baseline and at subsequent follow-up (six months, one year, three years and five years).

The average delay between the first symptoms and the first medical consultation with a general practitioner was 37 weeks (CI: 27–46). The average delay between the first medical consultation and the referral to orthopaedic oncology was 54 weeks (CI: 43–65). The delay between the first consultation with a general practitioner and the first radiologic test was 31 weeks (CI: 22–39). The delay between the first radiologic test and the referral to orthopaedic oncology was 28 weeks (CI 24–32). The delay between the referral to orthopaedic oncology and the first appointment to our centre was three weeks (CI 2–4). Before the referral to our center, 23% of the patients met two general practitioners and 10% met with 3 or more general practitioner. Fifty-two pervent of the patients had a consultation with a specialist and 19% saw two or more specialists.

It is imperative to raise awareness of musculoskeletal tumours and indication for early referral in general practitioners. One of the main problems in our actual referral patern is early access to appropriate imaging. The creation of a referral program with specific guidelines is, in our opinion, the best way to significantly reduce the delays for appropriate management of patients with suspiscion of musculoskeletal tumours.

Kinematics of the knee change during the full range of flexion [1]. The lateral femoral condyle (LFC) rolls back progressively through the entire range of flexion. The medial femoral condyle (MFC) does not move back during the first 110 degrees, but from 110 to 160 degrees it moves back by 10mm. This dual arc makes anatomical knee design a challenging task. In medial rotation, during flexion, the MFC stays in place, but the LFC moves forward in extension and backward in flexion. In lateral rotation the LFC stays still while the MFC moves back and forward in flexion and extension. During central rotation both condyles move reciprocally. However the knee is stable against an anteriorly or posteriorly directed force. It is important that all these degrees of freedom and stability are reproduced in total knee replacement (TKR) design.

Furthermore, the two femoral condyles together form a spiral. Like the threads of a screw in a nut they allow medio-lateral translation of the femur [2] in the tibial reference frame. During flexion the knee centre moves laterally nearly 20% of the width of the tibial plateau and in extension the femur translates medially. This medio-lateral translation occurs in the natural normal knee joint. This has special significance in knee design because the natural femur (along with the trochlea) moves laterally in flexion, allowing the patella to be sited laterally, while most regular TKRs drive the patella medially. In order to test this anomaly we studied patellar maltracking in vivo and in cadavers.

In vivo tracking studies using a patellar tracker during total knee replacement demonstrated average patellar maltracking of 10mm with regular TKR designs. Experiments on 22 cadaveric limbs using loaded quadriceps mechanism and trackers on the femur, tibia and patella, showed that in the natural knee the patella tracked medially by an average of 5mm. In regular TKRs the patella tracked medially. Compared to a normal knee, the patella in these designs maltracked on average by 10mm. Spiral condyles applied to the same bone cuts in the cadavers allowed the patella tracking to return to the expected lateral position in flexion.

This has application to total knee replacement design. Unless the spiral design is incorporated in the condyles, patellar maltracking is inevitable and is likely to cause lateral knee pain and stiffness post-operatively.

Introduction

Corrosion products from modular taper junctions of hip prostheses have been implicated in adverse local tissue reactions after THR. Numerous factors have been proposed as the root causes of this phenomenon, including implant design and materials, manufacturing variables, intraoperative assembly, and patient lifestyle. As significant taper damage only occurs in a few percent of cases of THR, we have addressed this complication using a “forensic” examination of retrieval specimens to gain insight into the factors initiating the cascade leading to irreversible damage of the modular interface. In this study we report the categorization of over 380 retrievals into groups having shared damage patterns, metallic composition, and interface surface geometries to isolate the genesis of mechanically-assisted corrosion and its relation to intraoperative assembly, manufacturing, and postoperative loading.

Spinal fractures are common following underbody blast. Most injuries occur at the thoracolumbar junction, and fracture patterns suggest the spine is flexed at the moment of injury. However, current mechanistic descriptions of vertebral fractures are based on low energy injuries, and there is no evidence to correlate fracture pattern with posture at the loading rates seen in blast injury.

The T12-L1 segment of 4 human spines was dissected to preserve the paraspinal ligaments and potted in polymethylmecrylate. The specimens were impacted with a 14 kg mass at 3.5m/s in a drop tower; two specimens were impacted in neutral posture, one in flexion, and one in extension. A load cell measured the load history. CT scans and dissection identified the injury patterns.

Each specimen sustained a burst fracture. The neutral specimens demonstrated superior burst fractures, the flexed specimen demonstrated a superior burst fracture with significant anterior involvement, and the extended specimen showed a posterior vertebral body burst fracture.

At high loading rates, the posture of the spine at the moment of injury appears to affect the resulting fracture. This supports understanding the behaviour of the spine in blast injury and will allow improved mitigation system design in the future.

Introduction & Aims

The traditional method of soft-tissue balancing during TKA is subjective in nature, and stiffness and instability are common indications for revision, suggesting that TKA balancing by subjective assessment is suboptimal. This study examines the intraoperative mediolateral loads measured with a nanosensor-enabled tibial insert trial and the sequential balancing steps used to achieve quantitative balance. Data obtained from a prospective multicenter study was assessed to determine the effect of targeted ligament release on intra-articular loading, and to understand which types of releases are necessary to achieve quantified ligament balance.

Introduction

Robotically-assisted unicondylar knee arthroplasty (UKA) is intended to improve the precision with which the components are implanted, but the impact of alignment using this technique on subsequent polyethylene surface damage has not been determined. Therefore, we examined retrieved ultra-high-molecular-weight polyethylene UKA tibial inserts from patients who had either robotic-assisted UKA or UKA performed using conventional manual techniques and compared differences in polyethylene damage with differences in implant component alignment between the two groups. We aimed to answer the following questions: (1) Does robotic guidance improve UKA component position compared to manually implanted UKA? (2) Is polyethylene damage or edge loading less severe in patients who had robotically aligned UKA components? (3) Is polyethylene damage or edge loading less severe in patients with properly aligned UKA components?

Over the last decade, there has been a growing body of level I evidence supporting non-operative management (focused on early range of motion and weight bearing) of acute Achilles tendon ruptures. Despite this emerging evidence, there have been very few studies evaluating its uptake. Our primary objective was to determine whether the findings from a landmark Canadian trial assessing the optimal management strategy for acute Achilles tendon ruptures influenced the practice patterns of orthopaedic surgeons in Ontario, Canada over a 12-year time period. As a second objective we examined whether patient and provider predictors of surgical repair utilisation differed before and after dissemination of the landmark trial results.

Using provincial health administrative databases, we identified Ontario residents 18 years of age and older with an acute Achilles tendon rupture from April 2002 to March 2014. The proportion of surgically repaired ruptures was calculated for each calendar quarter and year. A time-series analysis using an interventional autoregressive integrated moving average (ARIMA) model was used to determine whether changes in the proportion of surgically repaired ruptures were chronologically related to the dissemination of results from a landmark Canadian trial by Willits et al. (first quarter, 2009). Spline regression was then used to independently identify critical time-points of change in the surgical repair rate to confirm our findings. A multivariate logistic regression model was used to assess for differences in patient and provider predictors of surgical repair utilisation before and after the landmark trial.

From the second quarter of 2002 to the first quarter of 2010 the surgical repair rate remained constant at ∼21%, however, by the first quarter of 2014 it fell to 6.5%. A statistically significant decrease in the rate of surgical repair (P<0.001) was observed after the results from a landmark Canadian trial were presented at a major North American conference (February 2009). Both teaching and non-teaching hospitals demonstrated a decline in the surgical repair rate over the study period, however, only the decrease seen at non-teaching hospitals was found to be significantly associated with the dissemination of landmark trial results (P<0.001). All other predictors of surgical repair utilisation remained unchanged in the before-and-after analysis with the exception of patients 30 years of age and younger having a higher odds of undergoing surgical repair after the trial when compared to those 51 years of age and older.

The current study demonstrates that large, well-designed randomised trials, such as the one conducted by Willits et al. can significantly change the practice patterns of orthopaedic surgeons. Moreover, the decline in surgical repair rate observed at both teaching and non-teaching hospitals suggests both academic and non-academic surgeons readily incorporate high quality evidence in to their practice.

There are limited recent epidemiological data pertaining to the patterns of skeletal injury around the knee joint in adult patients. Data on fractures of the distal femur, proximal tibia and patella have been individually reported. We aimed to describe the collective epidemiological characteristics of all fractures around the knee.

We conducted a retrospective analysis of a prospectively collected fracture database from an institution serving 545,000 adults. The demographic and injury details for all patients suffering fractures of the distal femur, proximal tibia and patella were analysed. Fractures were classified according to the AO (distal femur, patella) and Schatzker (proximal tibia) systems.

A total of 173 fractures occurred in 170 patients (60% women), representing 6.7% of all lower limb fractures. There were 36 distal femoral fractures, 82 proximal tibial fractures (metaphyseal, plateau or bony avulsions) and 55 patella fractures.

Each fracture type displayed distinct epidemiological characteristics. Injuries of the distal femur occurred in older women. A proportion of tibial plateau fractures occurred in young men following high-energy trauma, but a greater number were encountered by older men and women following low-energy injury. The majority of fractures around the knee were caused by a simple fall from standing, followed by road traffic accidents, and falls from height.

When compared with historical data from our unit, the incidence of fractures around the knee has increased. The median age of affected patients has also risen, and this is particularly true for fractures of the distal femur and tibial plateau.

The epidemiological characteristics of fractures around the knee joint in our adult population are presented. Low-energy trauma in the elderly is likely to constitute an increasing proportion of knee injuries in the future, and this has implications for the provision of trauma services in our region.

Our knowledge of the trabecular framework is restricted to a two dimensional study of trabecular framework of the proximal femur. The author has been studying the trabecular pattern of all bones of the lower limb, including the pelvis, for the past 25 years.

The material for the study included cadaveric bones: 10 innominate bones, three hundred femora, 50 tibia, 30 talus, 30 calcanei. 5mm, sections in coronal, sagittal, transverse, (and in proximal femur - oblique) plane were obtained of the cadaveric bones. These were studied by naked eye observation, with a magnifying glass, after obtaining high resolution photographs, and radiographs of sections.

The most constant feature has been the arcuate arrangement of trabeculae as a reflection of joint mobility. In the proximal femur this was observed in three planes while around the knee, and ankle + foot it was observed only in the sagittal plane. The trabeculae are aligned in a fashion similar to the Meyer - Cullmann model of a loaded beam fixed at one end. This reflects response to movements in three planes in the hip, and in sagittal plane around knee and ankle. It was also observed that trabeculae are continuous across joints indicating lines of stress at individual joints.

The author concludes that it is essential to study trabeculae in three dimensional perspective in order to design implants for various regions. This study will also help in designing of components for joint replacement.

Purpose

Intra-articular fractures of the distal radius are common injuries. Their pathogenesis involves a complex combination of forces, including ligament tension, bony compression and shearing, leading to injury patterns that challenge the treating surgeon. The contribution of the radiocarpal and radioulnar ligaments to articular fracture location has not previously been described. Computed tomography (CT) scanning is an important method of evaluating intra-articular distal radius fractures, revealing details missed on plain radiographs and influencing treatment plans.