The clinical success and long-term outcomes of total knee arthroplasty (TKA) depend not only on the accuracy of femoral and tibial components positioning, but also on the restoration of a proper mechanical axis (MA). Coronal and rotational mal-alignment may affect significantly the final result of a knee replacement. Patient specific cutting guides and intra-operative Computer-Assisted Surgery (CAS) have recently been introduced as options to improve implant alignment during TKA. The purpose of this study was to compare the alignment accuracy and implant positioning of Patient Matched technique to CAS system in patients with primary TKA. A cohort of 68 consecutive patients who underwent TKA was enrolled for this study: 34 patients received a TKA using CAS system while 34 patients received a TKA using a MRI-based Patient Matched system. Mechanical axis and kinematics were digitally measured pre- and post-operatively in all knees using the intra-operative navigation system but data were blinded for the operating surgeon in the Patient Matched group. A post-operative CT-scan evaluation was performed in all patients to analyse the prosthetic components alignment (coronal, sagittal and axial alignment according to Perth Protocol from CT-scan). CT-scan measurements were used as landmarks as this tool is considered the gold standard. MA, posterior tibial slope (PTS) and femoral component rotation (FCR) in CAS group were compared to data of Patient Matched group. All patients also underwent a clinical evaluation with Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS) at 6 and 12 months of follow up. KSS, KOOS and range of motion were comparable in the two groups after surgery. Operative time was significantly shorter in the Patient Matched group. No differences were found regarding complications rate. Mean angles, respectively for CAS and Patient Matched groups, were the following: MA was 1,7° (SD 0,9°) vs 0.8° (SD 2.1°); PTS was 3.1° (SD 0.9°) vs 3.4° (SD 2.1°); FCR was 1.5° (SD 2.2°) vs 1.36° (DS 1.2°). The outcomes of the CT scan evaluation were the following: MA was 1.5° (SD 0.8°) vs 1.0° (DS 1.5°); PTS was 2.3° (SD 0.8°) vs 3.0° (SD 2.6°); FCR was 0.4° (SD 0.8°) vs 0.2° (SD 0.3°). MA was within 3° of neutral alignment in 94% of patients for CAS group and in 97% of knees for Patient Matched group. After a short follow up, there weren't statistically significant differences between CAS and Patient Matched techniques as regards clinical and functional scores. Both the systems achieved the goal of neutral alignment within 3° of varus and valgus. We only observed greater precision for Patient Matched technique in optimizing femoral component rotation. Actually it is unpredictable if this difference may determine long term effects. Patient Matched technique and CAS for TKA surgery will certainly continue to have an impact in the future. Studies are needed to define which technique is better, in terms of long term results, failure rate and cost-effectiveness

Introduction. Neck of femur (NoF) fractures have an inherent 6.5% 30-day mortality as per National hip fracture database(2019). Several studies have demonstrated a higher mortality rate in covid positive NoFs but have been unable to demonstrate whether there are risk factors that contribute to the risk of mortality in this patient group or whether COVID is solely responsible for the higher mortality. Aims. To assess risk factors that are concurrently present in a fracture NoF cohort that may contribute to higher mortality in COVID positive patients. Methods. A cross sectional, retrospective study was performed for a period of 1 year starting from 1st March 2020. All surgically treated neck of femur fracture patients having an isolated intra/extracapsular fracture were included in the study. Data fields recorded- patient demographics, date and time of admission, ward discharge, surgery, mode of surgery (fixation/arthroplasty), prehospital AMTS score, residential status and mobility, ASA grade as per anaesthetist's records, date of death (if deceased), cause of death (as per death certificate/ postmortem / coroner's report). Analysis of mortality was carried out by creating a matched comparison group for each risk factor as well as some combinations. Results. 344 patients were surgically treated for a neck of femur fracture in our DGH during the period of 1st March 2020 to 28th February 2021. 46 patients did not receive a COVID swab (reasons unknown) and were excluded from the study. 35 patients had a COVID-19 RT PCR positive test during their hospital stay and 264 patients remained negative. There were 12 deaths in COVID positive patients (34%) and 53 deaths in COVID negative patients (20%) within the time frame of the study. For each risk factor matched group COVID was seen to confer higher mortality in general. There was no mortality in ASA 1 or 2 patients. Mortality rates in matched groups for age and ASA revealed 23.8% mortality in COVID positive as opposed to 17.3% in COVID negative for ASA 3 and 33.3% mortality in COVID positive vs. 28% in ASA 4. 11 out of the 12 COVID positive patients who died had an AMTS score >6. No correlation was seen between COVID positive deaths and preinjury residential status, type of fracture or surgery offered, or preinjury mobility. The average length of hospital stay was much higher for COVID positive patients (19.5days) as compared to 9.5 days for COVID negative patients. Conclusion. Matched group analysis show that there is a 37.5% increase in COVID positive neck of femur fracture mortality in ASA 3 patients, the same number falls to 17.8% for ASA 4 patients. These figures are much lower compared to other studies in the UK. There is a need to understand the real cause of death in this subset and to improve death certification so that we can differentiate between patients whose mortality is ‘due to’ or ‘With’ COVID

Introduction. In the lower extremity, lymphedema is characterized by fluid buildup and swelling which can lead to fibrosis of the skin and recurring soft-tissue infections. Risk factors include obesity, older age, lower extremity surgery, and radiotherapy. There is currently a paucity of data examining the impact of lymphedema in primary total knee arthroplasty (TKA). The purpose of this study was to review outcomes following primary TKA performed in patients with lymphedema compared to a matched cohort with primary osteoarthritis. Methods. Over a 19-year period (1998–2016), 144 patients underwent primary TKA with a preceding diagnosis of ipsilateral lymphedema (Table 1). There were 114 (79%) females, a mean age of 69 years, and mean BMI of 37.1 kg/m2. Mean follow-up was 7-years (range 2–17 years). A blinded analyst completed a 1:2 match of patients with lymphedema to a group of patients without lymphedema undergoing primary TKA for osteoarthritis during the same period. Matching criteria included sex, age, date of surgery, and BMI. Matched controls included 228 (79%) females along with a mean age and BMI of 69 and 36.4 kg/m2. The mean follow-up for the comparison cohort was 8 years (range 2–18 years). There were no significant differences between groups on the evaluated baseline parameters. Results: Patients with a history of lymphedema were at a significantly increased risk of revision TKA (HR 7.60, P<0.001), reoperation for any cause (HR 2.87, P<0.001), and postoperative infection (HR 6.19, P<0.001). Patients with lymphedema were also at increased risk for periprosthetic fracture (p=0.04) and tibial component loosening (p=0.01). Morbid obesity increased the risk of reoperation (HR 2.11, p=0.02) and trended toward increased risk of revision TKA (HR 2.29, p=0.059) and infection (HR 2.37, p=0.06). Discussion: Patients with lymphedema are at significantly increased risk of revision, reoperation, and infection following primary TKA. This data highlights the need for appropriate patient counseling in this population and optimization of lymphedema management before and after TKA. Results. Patients with a history of lymphedema were at a significantly increased risk of revision TKA (HR 7.60, P<0.001), reoperation for any cause (HR 2.87, P<0.001), and postoperative infection (HR 6.19, P<0.001). Patients with lymphedema were also at increased risk for periprosthetic fracture (p=0.04) and tibial component loosening (p=0.01). Morbid obesity increased the risk of reoperation (HR 2.11, p=0.02) and trended toward increased risk of revision TKA (HR 2.29, p=0.059) and infection (HR 2.37, p=0.06). Discussion. Patients with lymphedema are at significantly increased risk of revision, reoperation, and infection following primary TKA. This data highlights the need for appropriate patient counseling in this population and optimization of lymphedema management before and after TKA. For any figures or tables, please contact authors directly

Most hip replacements are performed in an in-patient setting; however, there has been a shift in recent years in Canada towards doing more on an outpatient basis. In 2021–2022, 15.6% of hip replacements were performed as day surgeries compared to 0.7% in 2018–2019. This analysis will assess patient reported outcome measures of patients who had inpatient versus outpatient hip replacement surgery between 2018 and 2021.

We analysed a retrospective sample of 4917 adult patients who had an elective primary unilateral hip replacement. Preoperative and three-month postoperative PROMs were completed - the Oxford Hip Score, EQD5L and patient satisfaction with the outcome were recorded. Patients who had an outpatient procedure were matched 1:1 with patients who are admitted to hospital for surgery based on age, sex and pre-COVID versus the COVID (March 15, 2020 as the start). Preoperative PROMs and Charlson Comorbidity Index were collected. T-tests and chi-square tests were used to assess the differences.

The inpatient group on average was older, female and had a lower preoperative PROMs score and more comorbidities than the outpatient group. With cohort matching the sample consisted of 1244 patients. The inpatient and outpatient groups have similar Oxford scores, postoperative EQ-5D-5L scores and the proportion satisfied with their surgical results. The Oxford postoperative score was slightly higher in the outpatient group compared to the inpatient group; however, this is not clinically significant.

We observed that outpatient protocols have no difference in patient satisfaction, self-reported functional outcomes and self-reported health-related quality of life three months after a hip replacement. Day surgery protocols represented potential solution to the challenges caused by the expected increase in demand for hip replacements. Our results demonstrated that patients do well clinically with day surgery procedures and there does not appear to be any detrimental effect on PROMs.

There is no agreement as to the superiority or specific indications for cast treatment, percutaneous pinning or open fracture fixation for Bennett's fractures of the thumb metacarpal. We undertook this study to compare the outcomes of treatment for patients treated for Bennett's fracture in the medium term.

We reviewed 33 patients treated in our unit for a bennett's fracture to the thumb metacarpal with closed reduction and casting. Each patient was matched with a patient treated surgically. Patients were matched for sex, age, Gedda grade of injury and hand dominance. Patients were reviewed at a minimum of 5-years and 66-patients were reviewed in total. Patients were examined clinically and also asked to complete a DASH questionnaire score and the brief Michigan hand questionnaire. Follow up plain radiographs were taken of the thumb and these were reviewed and graded for degenerative change using the Eaton-Littler score.

Sixty-six patients were included in the study, with 33 in the surgical and non-surgical cohorts respectively. The average age was 39 years old. In each cohort, 12/33 were female, 19/33 were right-handed with 25% of individuals injuring their dominant hand. In each coort there were 16 Grade 1 fractures, 4 Grade 2 and 13 Grade 3 fractures. There was no difference between the surgically treated and cast-treatment cohorts of patients when radiographic arthritis, pinch grip, the brief Michigan Hand Questionnaire and pain were assessed at final review. The surgical cohort had significantly lower DASH scores at final follow-up. There was no significant difference in the normalised bMHQ scores.

Our study was unable to demonstrate superiority of either operative or non-operative fracture stabilization. Patients in the surgical cohort reported superior satisfaction and DASH scores but did not demonstrate any superiority in any other objectively measured domain.

Abstract

The reverse total shoulder replacement (rTSR) has excellent clinical outcomes and prosthesis longevity, and thus, the indications have expanded to a younger age group. The use of a stemless humeral implant has been established in the anatomic TSR; and it is postulated to be safe to use in rTSR, whilst saving humeral bone stock for younger patients. The Lima stemless rTSR is a relatively new implant, with only one paper published on its outcomes.

This is a single-surgeon retrospective matched case control study to assess short term outcomes of primary stemless Lima SMR rTSR with 3D planning and Image Derived Instrumentation (IDI), in comparison to a matched case group with a primary stemmed Lima SMR rTSR with 3D planning and IDI.

Outcomes assessed: ROM, satisfaction score, PROMs, pain scores; and plain radiographs for loosening, loss of position, notching. Complications will be collated. Patients with at least 1 year of follow-up will be assessed.

With comparing the early radiographic and clinical outcomes of the stemless rTSR to a similar patient the standard rTSR, we can assess emerging trends or complications of this new device.

41 pairs of stemless and standard rTSRs have been matched, with 1- and 2-year follow up data. Data is currently being collated. Our hypothesis is that there is no clinical or radiographical difference between the Lima stemless rTSR and the traditional Lima stemmed rTSR.

This study aimed to verify the hypothesis that an antibiotic loaded hydrogel, defensive antimicrobial coating (DAC), reduces overall complication and infection rates when used for high-risk primary and revision total hip arthroplasty (THA).

This was a retrospective study matched cohort study of 238 patients, treated with cementless implants with and without DAC. A sub-group analysis of patients undergoing 2nd stage revision THA for prosthetic joint infection (PJI) was also conducted. Re-infection rates within 2 years, complications necessitating surgical intervention and radiographic analysis for aseptic loosening was assessed.

The mean age was 68.3±11.5 years, with 39 (32.8%) Macpherson class A, 64 (53.8%) class B and 16 (13.4%) class C patients. 4 (3.4%) patients in the DAC group developed complications including 1 PJI and 1 delayed wound healing, while 13 (10.9%) patients in the control group developed complications including 5 PJIs and 3 delayed wound healing (p=0.032). PJI rates (p=0.136) and delayed wound healing rates (p=0.337) were not statistically significant. For 2nd stage revision THA for PJI there were 86 patients in the DAC group and 45 in the control group. 1 (1.2%) patient in the DAC group developed complications with no recurrences of infection or delayed wound healing, while 10 (22.2%) patients in the control group developed complications including 4 recurrent PJI and 1 delayed wound healing (p=0.003). Recurrent PJI rates were statistically significant (p=0.005) while delayed wound healing rates were not (p=0.165). Patients treated with DAC also had lower rates of aseptic loosening (0% vs 6.7%; p=0.015).

Antibiotic impregnated hydrogel coatings on cementless implants showed decreased complication rates after complex primary or revision THA. In 2nd stage revision THA for PJI, it was associated with reduced risk of re-infection and aseptic loosening.

Introduction

Ankle fractures in the elderly have been increasing with an ageing but active population and bring with them specific challenges. Medical co-morbidities, a poor soft tissue envelope and a requirement for early mobilisation to prevent morbidity and mortality, all create potential pitfalls to successful treatment. As a result, different techniques have been employed to try and improve outcomes. Total contact casting, both standard and enhanced open reduction internal fixation, external fixation and most recently tibiotalocalcaneal (TTC) nailing have all been proposed as suitable treatment modalities. Over the past five years popular literature has begun to herald TTC nailing as an appropriate and contemporary solution to the complex problem of high-risk ankle fragility fractures. We sought to assess whether, within our patient cohort, the outcomes seen supported the statement that TTC has equal outcomes to more traditional open reduction internal fixation (ORIF) when used to treat the high-risk ankle fragility fracture.

The 22 year survivorship of metal on metal hip resurfacing arthroplasty (RSA) is reported to be 94.3% with expert surgeons, in males with head sizes greater than 48mm. The 2023 National Joint Registry (NJR) report estimates survivorship of all RSA at 19 years to be 85%. This estimate includes all designs, head sizes and females. Our aim was to estimate the survivorship of RSA currently available for implantation (males only, head size >48mm, MatOrtho Adept or Smith and Nephew Birmingham Hip Resurfacing (BHR)) in those under 55 years, performed by all surgeons, compared to conventional THR.

We performed a retrospective analysis of the NJR. We included all males under 55 years who had undergone BHR or Adept RSA with head size greater than 48mm. Propensity score matching was used to produce two comparable groups of patients for RSA or conventional THR. We matched in a 3:1 ratio (THR:RSA) using sex, ASA, BMI group, age at primary procedure, surgeon volume, diagnosis and surgeon grade as covariates. The primary analysis was survivorship at 18 years. Time-to-revision was assessed using Kaplan-Meier curves. Cox's proportional hazard models were used to investigate between group differences.

4839 RSA were available for analysis. After matching the RSA and THR groups were well balanced in terms of covariates. Survivorship at 18 years was 93.7% (95% CI 89.9,96.2) in the RSA group and 93.9% (90.5,96.0) in the THR group. Despite these similar estimates the adjusted hazard ratio was 1.40 (95% CI 1.18, 1.67 p<0.001) in favour of THR.

Survivorship of the currently available RSA in males under 55 was 93.7% at 18 years, however THR survivorship was superior to RSA. These results, generalisable to UK practice, should be set against perceived benefits in functional status offered in RSA when counselling patients.

Background

Recurrent patellar dislocation in combination with cartilage injures are difficult injuries to treat with confounding pathways of treatment. The aim of this study is to compare the clinical and functional outcomes of patients operated for patellofemoral instability with and without cartilage defects.

Introduction

The Te Whatu Ora Southern catchment area covers the largest geographical region in New Zealand (over 62,000 km2) creating logistical challenges in providing timely access to emergency neck of femur (NOF) fracture surgery. Current Australian and New Zealand guidelines recommend that NoF surgery be performed within 48 hours of presentation. The purpose of this study was to compare the outcomes for patients with NoF fractures who present directly to a referral hospital (Southland Hospital) compared to those are transferred from rural peripheral centres.

The purpose of this study was to compare intra-operative, clinical, functional, and patient-reported outcomes following revision anterior cruciate ligament reconstruction (ACL-R) with a matched cohort of primary isolated ACL-R. A secondary purpose was to compare patient-reported outcomes within revision ACL-R based on intra-operative cartilage pathology.

Between January 2010 and August 2017, 396 patients underwent revision ACL-R, and were matched to primary isolated ACL-R patients using sex, age, body mass index (BMI), and Beighton score. Intra-operative assessments including meniscal and chondral pathology, and graft diameter were recorded. Lachman and pivot shift tests were completed independently on each patient at two-years post-operative by a physiotherapist and orthopaedic surgeon. A battery of functional tests was assssed including single-leg Bosu balance, and four single-leg hop tests. The Anterior Cruciate Ligament-Quality of Life Questionnaire (ACL-QOL) was completed pre-operatively and two-years post-operatively.

Descriptive statistics including means (M) and standard deviations (SD), and as appropriate paired t-tests were used to compare between-groups demographics, the degree and frequency of meniscal and chondral pathology, graft diameter, rate of post-operative ACL graft laxity, the surgical failure rate, and ACL-QOL scores. Comparative assessment of operative to non-operative limb performance on the functional tests was used to assess limb symmetry indices (LSI).

Revision ACL-R patients were 52.3% male, mean age 30.7 years (SD=10.2), mean BMI 25.3 kg/m2 (SD=3.79), and mean Beighton score 3.52 (SD=2.51). In the revision group, meniscal (83%) and chondral pathology (57.5%) was significantly more frequent than in the primary group (68.2% and 32.1%) respectively, (p < 0 .05). Mean graft diameter (mm) in the revision ACL-R group for hamstring (M=7.89, SD=0.99), allograft (M=8.42, SD=0.82), and patellar or quadriceps tendon (M=9.56, SD=0.69) was larger than in the primary ACL-R group (M=7.54, SD=0.76, M=8.06, SD=0.55, M=9, SD=1) respectively. The presence of combined positive Lachman and pivot shift tests was significantly more frequent in the revision (21.5%) than primary group (4.89%), (p < 0 .05). Surgical failure rate was higher in the revision (10.3%) than primary group (5.9%).

Seventy-three percent of revision patients completed functional testing. No significant LSI differences were demonstrated between the revision and primary ACL-R groups on any of the functional tests. No statistically significant differences were demonstrated in mean preoperative ACL-QOL scores between the revision (M=28.5/100, SD=13.5) and primary groups (M=28.5/100, SD=14.4). Mean two-year scores demonstrated statistically significant and minimally clinically important differences between the revision (M=61.1/100, SD=20.4) and primary groups (M=76.0/100, SD=18.9), (p < 0 .05). Mean two-year scores for revision patients with repair of the medial (M=59.4/100, SD=21.7) or lateral meniscus (M=59.4/100, SD=23.6), partial medial meniscectomy (M=59.7/100, SD=20), grade three or four osteoarthritis (M=55.9/100, SD=19.5), and medial femoral condyle osteoarthritis (M=59.1/100, SD=18) were lower compared with partial lateral meniscectomy (M=67.1/100, SD=19.1), grade one or two osteoarthritis (M=63.8/100, SD=18.9), and lateral femoral condyle osteoarthritis (M=62, SD=21).

Revision ACL-R patients demonstrated a greater amount of meniscal and chondral pathology at the time of surgery. Two-years post-operative these patients demonstrated higher rates of graft laxity and lower ACL-QOL scores compared with the primary ACL-R group. Higher grade and medial sided osteoarthritis was associated with inferior ACL-QOL scores in revision ACL-R.

Introduction

A subset of patients in cast awaiting fixation of ankle fractures require conversion to delayed external fixation (dEF). We aimed to evaluate the effect of delayed versus planned external fixation (pEF), then identify objective characteristics contributing to need for conversion.

Introduction

The proportion of arthroplasties performed in the ambulatory setting has increased substantially. However, concerns remain regarding whether same-day discharge may increase the risk of complications. The purpose of this study was to compare 90-day outcomes between inpatients and patients having surgery at an ambulatory surgery center (ASC).

Introduction

The proportion of arthroplasties performed in the ambulatory setting has increased substantially. However, concerns remain regarding whether same-day discharge may increase the risk of complications. The purpose of this study was to compare 90-day outcomes between inpatients and patients having surgery at an ambulatory surgery center (ASC).

Symptomatic lumbar spinal stenosis is a common entity and increasing in prevalence. Limited evidence is available regarding patient reported outcomes comparing primary vs revision surgery for those undergoing lumbar decompression, with or without fusion. Evidence available suggest a lower rate of improvement in the revision group. The aim of this study was to assess patient reported outcomes in patients undergoing revision decompression, with or without fusion, when compared to primary surgery.

Patient data was collected from the Canadian Spine Outcomes Research Network (CSORN) database. Patients undergoing lumbar decompression without or without fusion were included. Patients under 18, undergoing discectomy, greater than two level decompressions, concomitant cervical or thoracic spine surgery were excluded. Demographic data, smoking status, narcotic use, number of comorbidities as well as individual comorbidities were included in our propensity scores. Patients undergoing primary vs revision decompression were matched in a four:one ratio according to their scores, whilst a separate matched cohort was created for those undergoing primary vs revision decompression and fusion. Continuous data was compared using a two-tailed t-test, whilst categorical variables were assessed using chi-square test.

A total of 555 patients were included, with 444 primary patients matched to 111 revision surgery patients, of which 373 (67%) did not have fusion. Patients undergoing primary decompression with fusion compared to revision patients were more likely to answer yes to “feel better after surgery” (87.8% vs 73.8%, p=0.023), “undergo surgery again” (90.1% vs 76.2%, P=0.021) and “improvement in mental health” (47.7% vs 28.6%, p=0.03) at six months. There was no difference in either of these outcomes at 12 or 24 months. There was no difference between the groups ODI, EQ-5D, SF 12 scores at any time point. Patients undergoing primary vs revision decompression alone showed no difference in PROMs at any time point.

In a matched cohort, there appears to be no difference in improvement in PROMS between patients undergoing primary vs revision decompression, with or without fusion, at two year follow-up. This would suggest similar outcomes can be obtained in revision cases.

Abstract

A total of 31 patients, (20 women, 11 men; mean age 62.5 years old; 23 to 81), who underwent conversion of a Girdlestone resection-arthroplasty (RA) to a total hip replacement (THR) were compared with 93 patients, (60 women, 33 men; mean age 63.4 years old; 20 to 89), who had revision THR surgery for aseptic loosening in a retrospective matched case-control study. Age, gender and the extent of the pre-operative bone defect were similar in all patients. Mean follow-up was 9.3 years (5 to 18).

Pre-operative function and range of movement were better in the control group (p = 0.01 and 0.003, respectively) and pre-operative leg length discrepancy (LLD) was greater in the RA group (p < 0.001). The post-operative clinical outcome was similar in both groups except for mean post-operative LLD, which was greater in the study group (p = 0.003). There was a significant interaction effect for LLD in the study group (p < 0.001). A two-way analysis of variance showed that clinical outcome depended on patient age (patients older than 70 years old had worse pre-operative pain, p = 0.017) or bone defect (patients with a large acetabular bone defect had higher LLD, p = 0.006, worse post-operative function p = 0.009 and range of movement, p = 0.005), irrespective of the group.

Despite major acetabular and femoral bone defects requiring complex surgical reconstruction techniques, THR after RA shows a clinical outcome similar to those obtained in aseptic revision surgery for hips with similar sized bone defects.

Cite this article: Bone Joint J 2014;96-B:1478–84.

Given the high prevalence of psychiatric illness in the total joint arthroplasty (TJA) population, relatively little is known about how these two conditions affect each other. Therefore, the purpose of this study is to evaluate the role of major psychiatric illness on patient specific outcomes after TJA. We hypothesize that patients with major psychiatric illnesses will report inferior outcomes and have more complications after TJA compared to those without any psychiatric illness.

We matched and compared two cohorts of patients undergoing TJA from a prospectively collected database registry, which included those with and without a major psychiatric disorder. Major psychiatric disorder was identified in the registry database by determining if patients had been formally diagnosed with any of the following conditions: bipolar disorder, major personality disorder, chronic mental health diagnoses, depression, or schizophrenia. Primary outcomes of interest included patient specific outcomes measured using the WOMAC or EQ5D. Secondary outcomes included complications, infections, hospital length of stay, 30-day readmission rates and final discharge destination.

In total we included 1828 TJAs (1000 THAs, 828 TKAs). In terms of the primary outcome, both the THA experimental group (37.80 ± 17.91 vs. 40.74 ± 19.3, p=0.023) and TKA experimental group (43.38 ± 18.41 vs 45.45 ± 20.07, p=0.050) had significantly lower preoperative WOMAC scores compared to their respective control groups. At the 3-month period both the THA experimental group (76.74 ± 16.94 vs. 79.16 ± 16.19, p=0.036) and TKA experimental group (71.09 ± 18.64 vs. 75.92 ± 16.22, p=0) again had significantly lower 3-month postoperative WOMAC score. Clinical outcomes at the 1-year mark were similar for both groups in terms of WOMAC and EQ5D. Patients with psychiatric illness were more likely to have increased LOS and non-routine discharge from hospital. In the THA subset, the experimental group had an increased LOS by 1.43 days (p=0.0028), in the TKA subset, the experimental group had an increased LOS by 0.77 days (p= 0.050). In terms of non-routine discharge, the THA experimental group was discharged home 86.9% of the time compared to the control group at 91.8% (p=0.024). In the TKA subset, the experimental group was discharged home 87.6% of the time compared to the control group at 92% (p=0.022). There were no other differences between the two subsets in regards to transfusions, 30-day readmissions, infections, mechanical adverse events, and medical complications.

In conclusion, our results demonstrate that psychiatric illness can result in worse outcomes in the early perioperative period after TJA, although outcomes are equivalent 1 year postoperatively. Patients with psychiatric illness can be expected to gain significant improvements in outcome after surgery that are comparable to a baseline population without psychiatric illness. Nonetheless, patients with psychiatric illness are at increased risk of delayed discharge and non-routine discharge. As such, they may require personalized care post-operatively, and should be counseled accordingly. Based on our results, psychiatric illness should not be an impediment to proceeding with TJA.

Open reduction and internal fixation (ORIF) with trans-articular screws or dorsal plating is the standard surgical technique for displaced Lisfranc injuries. This aim of this study is to compare the clinical outcomes of percutaneous reduction and internal fixation (PRIF) of low energy Lisfranc injuries with a matched, control group of patients treated with ORIF.

Over a seven-year period (2012–2019), 16 consecutive patients with a low energy Myerson B2-type injury were treated with PRIF. Patient demographics were recorded within a prospectively maintained database at the institution. This study sample was matched for age, sex and mechanism of injury to a control group of 16 patients with similar Myerson B2-type injuries treated with ORIF. Clinical outcome was compared using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and Manchester Oxford Foot Questionnaire (MOXFQ).

At a mean follow up of 43.0 months (95% CI 35.6 – 50.4), both the AOFAS and MOXFQ scores were significantly higher in the PRIF group compared to the control ORIF group (AOFAS 89.1vs 76.4, p=0.03; MOXFQ 10.0 vs 27.6, p=0.03). There were no immediate postoperative complications in either group. At final follow up, there was no radiological evidence of midfoot osteoarthritis in any patient in the PRIF group. Three patients in the ORIF group developed midfoot osteoarthritis, one of whom required midfoot fusion.

PRIF is a technically simple, less invasive method of operative stabilisation of low energy Lisfranc injures which also appears to be associated with better mid-term clinical outcomes compared to ORIF.

While Oxidized Zirconium (OxZr) femoral heads matched with highly cross-linked polyethylene (XLPE) have demonstrated the lowest rate of revision compared to other bearing couples in the Australian National Joint Registry, it has been postulated that these results may, in part, be due to the fact that a single company offers this bearing option with a limited combination of femoral and acetabular prostheses. The purpose of this study was to assess clinical and radiographic outcomes in a matched cohort of total hip replacements (THR) utilizing an identical cementless femoral stem and acetabular component with either an Oxidized Zirconium (OxZr) or Cobalt-Chrome (CoCr) femoral heads at a minimum of 10 years follow-up.

We reviewed our institutional database to identify all patients whom underwent a THR with a single cementless femoral stem, acetabular component, XLPE liner and OxZr femoral head with a minimum of 10 years of follow-up. These were then matched to patients who underwent a THR with identical prosthesis combinations with CoCr femoral head by gender, age and BMI. All patients were prospectively evaluated with WOMAC, SF-12 and Harris Hip Score (HHS) preoperatively and postoperatively at 6 weeks, 3 months, 1 and 2 years and every 2 years thereafter. Charts and radiographs were reviewed to determine the revision rates and survivorship (both all cause and aseptic) at 10 years for both cohorts. Paired analysis was performed to determine if differences exist in patient reported outcomes.

There were 208 OxZr THRs identified which were matched with 208 CoCr THRs. There was no difference in average age (OxZr, 54.58 years, CoCr, 54.75 years), gender (OxZr 47.6% female, CoCr 47.6% female), and average body max index (OxZr, 31.36 kg/m2, CoCr, 31.12 kg/m2) between the two cohorts. There were no significant differences preoperatively in any of the outcome scores between the two groups (WOMAC (p=0.449), SF-12 (p=0.379), HHS(p=0.3718)). Both the SF12 (p=0.446) and the WOMAC (p=0.278) were similar between the two groups, however the OxZr THR cohort had slightly better HHS compared to the CoCr THR cohort (92.6 vs. 89.7, p=0.039). With revision for any reason as the end point, there was no significant difference in 10 years survivorship between groups (OxZr 98.5%, CoCr 96.6%, p=0.08). Similarly, aseptic revisions demonstrated comparable survivorship rates at 10 year between the OxZr (99.5%) and CoCr groups (97.6%)(p=0.15).

Both THR cohorts demonstrated outstanding survivorship and improvement in patient reported outcomes. The only difference was a slightly better HHS score for the OxZr cohort which may represent selection bias, where OxZr implants were perhaps implanted in more active patients. Implant survivorship was excellent and not dissimilar for both the OxZr and CoCr groups at 10 years. Therefore, with respect to implant longevity at the end of the first decade, there appears to be no clear advantage of OxZr heads compared to CoCr heads when paired with XLPE for patients with similar demographics. Further follow-up into the second and third decade may be required to demonstrate if a difference does exist.

The purpose of this study was to define the risk and incidence of eventual ankle arthroplasty or fusion after documented ankle fracture in a large cohort, and compare that rate to matched healthy patients from the general population.

The Ontario health insurance plan (OHIP) physician billing database, Institute for Clinical Evaluative Sciences (ICES) Physician Database, the Canadian Institute for Health Information (CIHI) databases, Discharge Abstract Database (DAD) and Same Day Surgery (SDS) were used to identify patients treated surgically and non-surgically for ankle fractures. Each patient was matched to four individuals from the general population (13.5 million) with no documented prior treatment for ankle fracture, according to age, sex, income, and urban/rural residence. Fusion and replacement incidence was compared using time-to-event analysis (Kaplan-Meier). A Cox Proportional Hazards model was used to explore the influence of patient, provider and surgical factors on time to surgery.

We identified 45,444 (58.8% female, mean age 48.7 years) and 140, 629 (53.9% female, mean age 47.1 years) patients who had undergone open reduction internal fixation (ORIF) or non-operative management of an ankle fracture (NOA), respectively. Among ORIF patients, n=237 (0.5%) and n=69 (0.15%) patients underwent fusion or arthroplasty after a median 2.8 and 6.9 years, respectively. Among non-operatively treated ankle fractures, n=198 (0.14%) and n=36 (0.03%) patients underwent fusion or arthroplasty after a median of 3.2 and 5.6 years, respectively. Surgical treatment (vs. non-operatively treated fracture), older age, greater co-morbidity and a history of infection post fracture significantly increased the risk of eventual fusion or arthroplasty (HR 3.6 (3.1–4.3), p < 0 .001, HR 1.01 (1.01–1.02), p=0.009, HR 1.2 (1.1–1.3), p < 0 .001, HR 11.3 (6.8–18.7), p < 0 .001, respectively). Compared to matched controls, the risk of fusion/arthroplasty was not independent of time, following an exponential decay pattern. ORIF patient risk was 20 times greater than the general population in the first three years post-ORIF, and approached the risk of non-operatively treated patients (HR 4.5 (95CI: 3.5–5.8), p < 0 .0001) by approximately 14 years out from injury on time and comorbidity adjusted KM curves.

Rates of fusion/arthroplasty are very low after ORIF and non-operative treatment of an ankle fracture in the general population of a public healthcare system. Utilization patterns suggest fusion is more common earlier, and arthroplasty remote, which may be a factor of patient age, injury severity, and complications from initial injury/surgery. Patients who underwent ORIF have >20 times the risk of fusion/arthroplasty in the short-term, however, the risk decreases over time eventually approaching that of non-operatively treated patients (∼4.5x the general population) when compared to non-fractured controls.

Introduction

Patient matched instrumentation (PMI) have been proposed the accuracy of bone cuts through custom cutting blocks and provide the proper alignment of total knee arthroplasty (TKA). On the other hand, there are some reports that the introduction of PMI for guiding bone cuts could increase the incidence of malalignment in primary TKA. Recent comparisons between patient-specific cutting guides and quantitative assessments of postoperative alignment have revealed the presence of outliers with respect to coronal alignment. The purpose of this study was to assess the implanted component alignment post-operatively between one type of MRI based PMI (Visionaire; Smith & Nephew, Inc, Memphis, Tenn) and conventional surgical instrumentation (CI) using radiographs and CT scan.

Purpose

The success of total knee replacement (TKR) surgery can be attributed to improvements in TKR design, instrumentation, and surgical technique. Over a decade ago oxidized zirconium (OxZr) femoral components were introduced as an alternative bearing surface to cobalt-chromium (CoCr), based on strong in-vitro evidence, to improve the longevity of TKR implants. Early reports have demonstrated the clinical success of this material however no long-term comparative studies have demonstrated the superiority of OxZr implants compared to a more traditional CoCr implant. This study aims to compare long-term survivorship and outcomes in OxZr and CoCr femoral components in a single total knee design.

The study sought to determine the results of labral restoration among patients over age 60 compared to a cohort of younger adults.

21 consecutive patients over age 60 undergoing labral repair with minimum one-year follow-up were compared to a contemporaneous group of 21 patients age 18–55 matched for gender, degree of chondral damage, and associated FAI or dysplasia.

Follow-up averaged 18.9 months (12 to 24 months). The study group averaged 63.2 years (61 to 71); with 20 FAI and one dysplasia. 19 had acetabular articular damage (2 grade IV, 11 grade III, 5 grade II, 1 grade I) and 6 had femoral changes (1 grade IV, 5 grade 3). The control group averaged 35.8 years (20 to 54).

Average improvement among the study group was 28.1 points modified Harris Hip Score (mHHS) and 37.5 points iHOT; and among the control group, 21.2 points mHHS and 37.1 points iHOT. There was no statistically significant difference between the two groups in the amount of improvement, with statistically and clinically significant improvement noted in both. Two study group patients underwent total hip arthroplasty (THA) at average 10 months with one control group THA at 11 months. All three converted to THA had combined grade IV acetabular and grade III femoral damage. There were no repeat arthroscopies and no complications in either group.

We conclude that patients over age 60 can benefit from arthroscopic labral repair with improved outcomes, modest rates of conversion to THA, and small risk of complication. Results are comparable to younger adults. Combined bipolar grade IV or grade III articular damage is a harbinger of conversion to THA, regardless of age.

The surgical treatment of unicompartmental knee osteoarthritis remains controversial. This study aims to compare the medium-term outcomes of age and gender matched patients treated with unicompartmental knee replacement (UKR) and total knee replacement (TKR).

We retrospectively reviewed pain, function and total knee society scores (KSS) for every UKR and age and gender matched TKR in NHS Tayside, with up to 10 years prospective data from Tayside Arthroplasty Audit Group. KSS was compared at 1, 3 and 5 years. Medical complications and joint revision were identified. Kaplan-Meier with revision as end-point was used for implants survival analysis.

602 UKRs were implanted between 2001 and 2013. Preoperative KSS for pain and total scores were not significantly different between UKRs and TKRs whereas preoperative function score was significantly better for UKRs. Function scores remained significantly better in UKRs from preoperative until 3 years follow up. Further analysis revealed no statistically significant difference in the change of function scores in both groups over time. There was a trend for TKRs to perform better than UKRs in pain scores. Total KSS for both groups were not significantly different at any point of the 5-year study. Fewer medical complications were reported in the UKR group. Kaplan-Meier analysis showed a survival rate of 93.7% in UKRs and of 97% in TKRs (Log rank p-value = 0.012).

The revision rate for UKR was twice as much as TKR. The theoretical advantages of UKR are not borne out by the findings in this study other than immediate postoperative complications.

The current study aims to compare the clinico radiological outcomes between Non-Fusion Anterior Scoliosis (NFASC) Correction and Posterior Spinal Fusion (PSF) for Lenke 5 curves at 2 years follow up.

Methods:38 consecutive Lenke 5 AIS patients treated by a single surgeon with NFASC (group A) or PSF (group B) were matched by age, Cobb's angle, and skeletal maturity. Intraoperative blood loss, operative time, LOS, coronal Cobbs, and SRS22 scores at 2 years were compared. Flexibility was assessed by modified Schober's test. Continuous variables were compared using student t-tests and categorical variables were compared using chi-square.

The cohort included 19 patients each in group A and B . Group A had M:F distribution of 1:18 while group B had 2:17. The mean age in group A and group B were 14.8±2.9 and 15.3±3.1 years respectively. The mean follow-up of patients in groups A and B were 24.5±1.8 months and 27.4±2.1 months respectively. Mean pre-op thoracolumbar/lumbar (TL/L) cobbs for group A and group B were 55°±7° and 57.5°±8° respectively. At two years follow up, the cobbs for group A and B were 18.2°±3.6° and 17.6°±3.5° respectively (p=0.09). The average operating time for groups A and B were 169±14.2 mins and 219±20.5 mins respectively (p<0.05). The average blood loss of groups A and B were 105.3±15.4 and 325.3±120.4 respectively (p<0.05). The average number of instrumented vertebra between groups A and B were 6.2 and 8.5 respectively (p<0.05). The average LOS for NFASC and PSF was 3.3±0.9 days and 4.3±1.1 days respectively (p<0.05). No statistically significant difference in SRS 22 score was noted between the two groups. No complications were recorded.

Our study shows no significant difference in PSF and NFASC in terms of Cobbs correction and SRS scores, but the NFASC group had significantly reduced blood loss, operative time, and fewer instrumented levels. NFASC is an effective alternative technique to fusion to correct and stabilize Lenke 5 AIS curves with preservation of spinal motion.

Introduction

In the United States, cementless femoral fixation remains the dominant mode of fixation for femoral neck fractures, despite strong worldwide registry data that supports cemented fixation. The reason for this discrepancy remains unknown, controversial and often difficult to compare due to multiple variables. The purpose of this study was to evaluate a matched cohort of patients undergoing arthroplasty for femoral neck fractures and assess outcomes of revisions, periprosthetic fractures and mortality.

Eligible patients were randomly allocated to PMI or standard intramedullary jigs. Smith and Nephew's patient specific cutting blocks (Visionaire) were used for PMI. Postoperative component positioning was investigated using the ‘Perth CT protocol’. Deviation of more than 3° from the recommended position was regarded as an outlier. Exact Mann-Whitney U test was used to compare component positioning and difference in proportion of outliers was calculated using Chi Squared analysis.

Fifty-five knees were enrolled in the standard instrumentation group and fifty-two knees in the PMI group.

Coronal femoral alignment was 0.7 ± 1.9° (standard) vs 0.5 ± 1.6° (PMI) (P=0.33). Outliers 9.4% vs 7.4% (P=0.71). Coronal tibial alignment was 0.4 ± 1.5° (standard) vs 0.6 ± 1.4° (PMI) (P=0.56). Outliers 1.9% vs 1.9% (P=0.99). Sagittal femoral alignment was 0.6 ± 1.5° (standard) vs 1.3 ± 1.9° (PMI) (P=0.07). Outliers 3.8% vs 13.2% (P=0.09). Tibial slope was 1.7 ± 1.9 ° (standard) vs 1.8 ± 2.7° (PMI) (P=0.88). Outliers 13.2% vs 24.1% (P=0.15). External rotation of femoral component was 0.6 ± 1.4° (standard) vs 0.2 ± 1.8° (PMI) (P=0.14). Outliers: 3.8% vs 5.6% (P=0.66).

Compared to standard intramedullary jigs, patient matched instrumentation does not improve component positioning or reduce alignment outliers.

Introduction

Unicompartmental knee replacement (UKR) offers advantages over total knee replacement but has higher revision rates particularly for aseptic loosening. Cementless UKR was introduced in an attempt to address this. We used National Joint Registry (NJR) data to compare the 10-year results of cemented and cementless mobile bearing UKR whilst matching for important patient, implant and surgical factors. We also explored the influence of caseload on outcome.

Aim

To assess the accuracy of predicted and actual cut alignment from PMCB versus intra-operative computer navigation.

Introduction

Hip resurfacing is a bone sparing approach to treating arthritis in younger or more active patients. Accurate positioning of the femoral component in the hip resurfacing procedure is essential for the success of the operation [1-2]. An alignment guide assisting the operator in accurately positioning the resurfacing implant may increases the success rate of the operation. This study focuses on the effectiveness of a CT based resurfacing alignment guide, shown in Figure 1.

Total knee arthroplasty is an established and successful operation. In up to 13% of patients who undergo total knee arthroplasty continue to complain of pain. Recently computerised tomography (CT) has been used to assess the rotational profile of both the tibial and femoral components in painful total knee arthroplasty.

We reviewed 56 painful total knee replacements and compared these to 56 matched patients with pain free total knee replacements. Patients with infection, aseptic loosening, revision arthroplasties and gross coronal malalignment were excluded. Datum gathered from case notes and radiographs using a prospective orthopaedic database to identify patients. The age, sex, preoperative and postoperative Oxford scores, visual analogue scores and treatments recorded. The CT information recorded was limb alignment, tibial component rotation, femoral component rotation and combined rotation.

The two cohorts of patients had similar demographics. The mean limb alignments were 1.7 degrees varus and 0.01 degrees valgus in the painful and control groups respectively. A significant difference in tibial component rotation was identified between the groups with 3.2 degrees of internal rotation in the painful group compared to 0.5 degrees of external rotation in the control group (p=0.001). A significant difference in femoral component rotation was identified between the groups with 3.8 degrees of internal rotation in the painful group compared to 1.1 degrees of external rotation in the control group (p=0.001). A significant difference in the combined component rotation was identified between the groups with 6.8 degrees of internal rotation in the painful group compared to 1.7 degrees of external rotation in the control group (p=0.001).

We have identified significant internal rotation in a patient cohort with painful total knee arthroplasty when compared to a control group with internal rotation of the tibial component, femoral component and combined rotation. This is the largest comparison series currently in the literature.

Aim

To compare the results of total knee replacement in a consecutive series of morbidly obese patients (body mass index (BMI) > 40 kg/m²) with a matched group of non-obese (BMI< 30 kg/m²) patients.

A comparative study on CT- and MRI-based patient specific matched guides (PSG) from the same manufacturer for the implantation of total knee arthroplasty (TKA) has not been undertaken.

A total of 64 knees operated with CT based PSG was divided into two groups, with (n=32, CT^HK) or without (n=32, CT^NA) a history of a knee operation, and matched with a control group operated with MRI based PSG(n=64). Alignment of the biomechanical axis of the leg (HKA angle) and accuracy of individual implant alignment were measured on digital long-standing AP and sagittal radiographs. HKA and implant angles <3° deviation of the preoperative planned alignment were defined as correct. Peroperative implant size, OR time (min) and blood loss (ml) were compared.

The average HKA angle in the CT^HK group (177.0, 170.5 to 181.5, p=0.016) and mean varus-valgus alignment of the tibia component in the MRI group (90.6, 85.6 to 94.1, p=0.003) were statistically significant different. None of the outcome on the frontal femoral and lateral tibial component were statistically significant different. Percentage <3° deviation of the preoperative planned femoral flexion-extension alignment was better in the MRI group (84%, p=0.002), compared to the CT^HK and CT^NA group (respectively 30% and 42%). Average operation time was statistically significant shorter in favour of the MRI group (53.1, 34 to 80, p≤0.00), compared to the CT^HK(70.8, 44 to 114) and CT^NA group (59.2, 41 to 78).

There is discrepancy between CT and MRI based PSG from the same manufacture because of patients who were not suitable for MRI due to history of a knee operation in the past. Whether these differences are clinically relevant is questionable. Future research needs to emphasise whether one of these two modalities, MRI or CT is superior compared to the other.

This retrospective matched cohort study tested the hypothesis that an incomplete periacetabular acetabuloplasty, as an added step to delayed open reduction, diminishes the risk of developing acetabular dysplasia.

29 hips from 23 patients with idiopathic DDH that underwent intentionally delayed open reduction and acetabuloplasty at our institution from 2003 to 2010 were matched for age at presentation and bilaterality to historic controls. These were 29 hips from 26 patients, treated with open reduction alone from 1989 to 2003. Residual dysplasia treated with pelvic osteotomy, AVN grade II-IV, and rate of re-intervention were the outcome measures.

The mean ages at diagnosis and at surgery were 8.62 weeks and 12.97 months, respectively. At latest follow-up, 27 hips in the acetabuloplasty group and 22 in the open reduction alone group had satisfactory radiographic outcome (Severin class Ia, Ib or II) (p=0.16). 18 of the 58 hips (31.0%) had AVN, 7 (24.14%) in the case group and 11(37.93%) in the control group. Further surgery was required in 15 of the 29 hips in the open reduction alone group. These included 2 revision of open reductions, 5 pelvic osteotomies, 3 varus derotation osteotomies, and 5 apo or epiphysiodesis whilst only one patient in the acetabuloplasty group required a medial screw epiphysiodesis for late lateral growth arrest. There is a positive association between the need for further surgery and open reductions alone: the odds ratio is 14.00 and the 95% confidence interval (1.97, 99.63), p=0.0017. The five hips in the open reduction alone group that required a pelvic osteotomy were intervened at an average of 31.45 (±9.07) months.

The addition of an incomplete periacetabular periacetabuloplasty to all hips undergoing open reduction eliminated residual acetabular dysplasia in this cohort whilst it does not appear to have deleterious effects, as evidenced by the similar Severin and McKay scores.

There has recently been a proliferation of image-based knee arthroplasty systems which utilize pre-operative radiological analysis of a patient's anatomy to identify the bone cuts required to correct their mechanical alignment. The aim of this was to assess the accuracy of one such system (Visionaire™, Smith and Nephew Inc.©)

Eleven cadavers were imaged using the Smith and Nephew Visionaire® MRI protocol to enable the production of cutting blocks individualized to the various specimens. These cutting blocks were then used to perform knee replacements on all cadavers. Post-operatively the validated Perth CT protocol was used to assess the position and rotational profile of each implant. These measurements were then compared to the pre-operative plan in order to assess the accuracy of implant placement.

Relative to the pre-operative target parameters, the femoral components were aligned in a mean 0.048° valgus (95% CI – 0.36° to 1.32°) with 1.8° extension (95% CI −0.1° to 4.5°) and externally rotated by a mean 0.66° (95% CI 1.08° internal rotation to 2.4° external rotation.) The tibial components were in a mean 0.29° of varus (95% CI – 0.68° to 1.27°) with a posterior tibial slope of 90.5° (95% CI 89.6° to 92.6°) and internally rotated by a mean 1.7° (range 10.1° internal rotation to 1.1° external rotation.)

The findings of our study suggest that the Visionaire system can produce accurate coronal implant alignment. The saggital and rotational alignment was not as reliable although these parameters may have been more prone to adverse influence by the limitations of the cadaveric model. Patient-matched knee arthroplasty technology offers significant potential benefits to both patient and surgeon and warrants further clinical investigation.

Introduction

Oxidized zirconium (OxZr) is used as a ceramic surface for femoral components in total knee arthroplasty (TKA). The aim of this study was to investigate its performance by examining retrieved femoral components and their corresponding PE inserts in matched comparison with conventional chrome/cobalt/molybdenum alloy (CrCoMo).

The aim of this study was to compare the long-term outcome from total knee replacement (TKR) in young versus old patients in terms of pain and functional outcome.

We used our arthroplasty database which recorded prospectively pain and American Knee Society scores at regular intervals over ten years after TKR. The procedures used a modern, cemented resurfacing type cruciate retaining prosthesis. A cohort of young patients (< 55 years) were identified. A control group of patients ≥ 56 was identified, matching for ASA, body mass index and underlying condition. Change over time was analysed using a factorial repeated measures ANOVA test, which allowed for investigation of difference between groups.

40 Knees in 26 patients were identified. 2 patients died prior to follow up, 2 were revised within the study period. (1 for infection at 2 years and one for change of poly at 7 years) and a further 4 were lost to follow up. 7 knees could not be matched and were excluded. This left a study group of 24 young and 24 older knees.

Pain scores (p=0.025) and American Knee Society “Knee” (p<0.001) and “Function” (p<0.001) scores changed significantly over time. There were however no statistical differences over the 10 year period in pain (p=0.436) and knee performance (0.618) but overall function was higher throughout the period in the younger group (=0.004).

Knee replacement in younger patients produces similar outcomes in terms of pain and function compared with older patients and TKR should not be withheld purely on account of age.

The aim of this study was to compare the long-term outcome from total knee replacement (TKR) in young versus old patients in terms of pain and functional outcome.

We used our arthroplasty database which recorded prospectively pain and American Knee Society scores at regular intervals over ten years after TKR. The procedures used a modern, cemented resurfacing type cruciate retaining prosthesis. A cohort of young patients (≤55 years) were identified. A control group of patients > 56 was identified, matching for ASA, body mass index and underlying condition. Change over time was analysed using a factorial repeated measures ANOVA test, which allowed for investigation of difference between groups.

40 Knees in 26 patients were identified. 2 patients died prior to follow up, 2 were revised within the study period. (1 for infection at 2 years and one for change of poly at 7 years) and a further 4 were lost to follow up. 7 knees could not be matched and were excluded. This left a study group of 24 young and 24 older knees.

Pain scores (p=0.025) and American Knee Society “Knee” (p<0.001) and “Function” (p<0.001) scores changed significantly over time. There were however no statistical differences over the 10 year period in pain (p=0.436) and knee performance (0.618) but overall function was higher throughout the period in the younger group (=0.004).

Knee replacement in younger patients produces similar outcomes in terms of pain and function compared with older patients and TKR should not be withheld purely on account of age.

Introduction

Unicondylar knee replacements (UKR) may be more effective compared to Total knee replacements (TKR) in unicompartmental arthritis. We report patient outcomes & satisfaction data in an age matched cohort of patients with either a UKR or TKR.

Introduction

Recent implant design trends have renewed concerns regarding metal wear debris release from modular connections in THA. Previous studies regarding modular head-neck taper corrosion were largely based on cobalt chrome (CoCr) alloy femoral heads. Comparatively little is known about head-neck taper corrosion with ceramic femoral heads or about how taper angle clearance influences taper corrosion. This study addressed the following research questions: 1) Could ceramic heads mitigate electrochemical processes of taper corrosion compared to CoCr heads? 2) Which factors influence stem taper corrosion with ceramic heads? 3) What is the influence of taper angle clearance on taper corrosion in THA?

A 51 years old female who experienced difficulty in gait ambulation due to secondary osteoarthritis of knee showed knee instability caused by paralysis associated with poliomyelitis and scoliosis. At the first medical examination, right knee range of motion was 0° to 90°, and spino malleolar distance (SMD) showed 72cm for the right leg, 78cm for the left leg, and the bilateral comparison of SMD indicated the leg length discrepancy of 6cm. The patient has a history of surgeries with an anterior – posterior instrument for the treatment of scoliosis, and with Langenskiöld method for the paralyzed right knee at the age of seventeen. The patient also experienced varus degeneration at the age of twenty seven, which was surgically treated with high tibial osteotomy. In this case, a reoperation of her right knee was performed due to the reoccurrence of the knee pain. Preoperative planning was performed using Patient-matched instrument (Signature; Biomet) which was created based on computed tomography data. Each part of osteotomy followed the resection guide by Signature, and a total knee arthroplasty was carried out using the Rotating Hinge Knee System (Zimmer, warsaw. Inc). Two week after the operation, the patient showed the ability to walk without any assistance, and has been in a good condition.

Introduction

The aim of this study is to investigate the accuracy and reliability of a Magnetic Resonance Imaging (MRI) based Patient Match Technology (PMT) system (VISIONAIRE, Smith & Nephew, Inc, Memphis, Tenn) by intraoperative use of VectorVision knee navigation software from BrainLAB (Redwood City, California, USA).

Introduction

There is no literature regarding the risk of a patient developing PJI after primary TKA if the patient has previously experienced PJI of a TKA or THA in another joint. The goal of this study was to compare the risk of PJI of primary TKA in this patient population compared to matched controls.

Aim

To assess the process of using patient matched cutting blocks in Primary TKA with respect to: radiology, the proposed engineering plans, the process in theatre and cost effectiveness. Background: Patient matched cutting blocks (PMCB) are the subject of much interest in primary TKA. Our unit has experience of over 100 cases with a single system.

Introduction

There is considerable interest in the orthopaedic community in understanding the multifactorial process of taper fretting corrosion in total hip arthroplasty (THA). Previous studies have identified some patient and device factors associated with taper damage, including length of implantation, stem flexural rigidity, and head offset. Due to the complexity of this phenomenon, we approached the topic by developing a series of matched cohort studies, each attempting to isolate a single implant design variable, while controlling for confounding factors to the extent possible. We also developed a validated method for measuring material loss in retrieved orthopaedic tapers, which contributed to the creation of a new international standard (ASTM F3129-16).

Purpose

Proper positioning of the components of a knee prosthesis for obtaining post-operative knee joint alignment is vital to obtain good and long term performance of a knee replacement. Although the reasons for failure of knee arthroplasty have not been studied in depth, the few studies that have been published claim that as much as 25% of knee replacement failures are related to malpositioning or malalignment [x].

The use of patient-matched cutting blocks is a recent development in orthopaedics. In contrast to the standard cutting blocks, they are designed to fit the individual anatomy based on 3D medical images. Thus, landmarks and reference axes can be identified with higher accuracy and precision. Moreover, stable positioning of the blocks with respect to the defined axes is easier to achieve. Both may contribute to better alignment of the components.

The objective of this study was to check the accuracy of femoral component orientation in a cadaver study using specimen-matched cutting blocks in six specimens; first for a bi-compartmental replacement, and then for a tri-compartmental replacement in the same specimen.

Aim

To assess the clinical outcome at 1 year of 30 cases of primary TKA performed with PMCB.