This study aims to determine satisfaction rates after hip and knee arthroplasty in patients who did not initially respond to PROMs, characteristics of non-responders, and contact preferences to maximise response rates. We performed a prospective cohort study of 709 patients undergoing THA and 737 patients undergoing TKA in a single centre in 2018. EQ-5D health related quality of life score and Oxford Hip/knee scores (OHS/OKS) were completed preoperatively and at 1year postoperatively via post when satisfaction was also assessed. Univariate, multivariate and receiver operator curve analysis were performed.

151/709 (21.2%) hip patients were non-responders, 83 (55.0%) of whom were contactable. 108/737 (14.6%) knee patients were non-responders, 91 (84.3%) of whom were contactable. There was no difference in satisfaction after arthroplasty between initial non-responders and responders for hips (74/81 vs 476/516, p=0.847) or knees (81/93 vs 470/561, p=0.480). Initial and persistent non-response was associated with younger age, higher BMIs and significantly worse preoperative PROMS for both hip and knee patients (p=0.05). Multivariate analysis demonstrated that younger age, higher BMI and poorer pre-operative OHS were independently associated with persistent non-response to hip PROMs (p<0.05). For the entire cohort (n=1352) patients <67 years were less likely to respond to postal PROMs with OR 0.63 (0.558 to 0.711). Using a threshold of >66.4 years predicted a preference for contact by post with 65.4% sensitivity and 68.1% specificity (AUC 0.723 (0.647-0.799 95%CI, p<0.001)).

Most initial non-responders were ultimately contactable with effort. Satisfaction rates were not inferior in patients who did not initially respond to PROMs.

The Olympia femoral stem is a stainless steel, anatomically shaped, polished and three-dimensionally tapered implant designed for use in cemented total hip arthroplasty (THA). The primary aim of this study was to determine the long-term survivorship, radiographic outcome, and patient reported outcome measures (PROMs) of the Olympia stem.

Between May 2003 and December 2005, 239 patients (264 THAs) underwent a THA with an Olympia stem in our institution. PROMs were assessed using the Oxford Hip Score (OHS), EuroQol-5 dimensions (EQ-5D) score and patient satisfaction at mean 10-years following THA. Patient records and radiographs were then reviewed at a mean of 16.5 years (SD 0.7, 15.3 to 17.8) following THA to identify occurrence of complications or revision surgery for any cause.

Mean patient age at surgery was 68.0 years (SD 10.9, 31–93 years). There were 156 women (65%, 176 THAs). Osteoarthritis was the indication for THA in 204 patients (85%). Stem survivorship at 10 years was 99.2% (95 % confidence interval [CI], 97.9%-100%) and at 15 years was 97.5% (94.6%–100%). The 15-year stem survival for aseptic loosening was 100%. Only one occurrence of peri-prosthetic fracture was identified, with no episodes of dislocation found. At a mean of 10 (SD 0.8, 8.7 –11.3) years follow-up, mean OHS was 39 (SD 10.3, range 7 – 48) and 94% of patients reported being very satisfied or satisfied.

The Olympia stem demonstrated excellent 10-year PROMs, very high rates of stem survivorship and negligible peri-prosthetic fracture and dislocation rate at final follow-up beyond 15 years.

Non-surgical osteoarthritis management includes analgesia escalation to oral opiates; however, tolerance can occur. This study aims to assess analgesic effects of opiate use pre-operatively and whether this influences outcome 1-year post-operatively in patients undergoing total hip/knee arthroplasty (THA/TKA).

This prospective study assessed 1487 patients undergoing primary THA (n=729) or TKA (n=758) for osteoarthritis, with 95 respectively reporting pre-operative opiate use >1 month. THA opiate users had significantly higher BMI (p=0.007) and more likely to suffer associated comorbidities. TKA opiate users were significantly younger (p<0.001), with higher BMI (p=0.019) and more likely to suffer associated comorbidities. Pre-operative quality of life (QoL) and joint specific function were significantly worse (Hip EQ-5D 0.17 vs 0.41, p<0.001, OHS 14.6 vs 21.2, p<0.001; Knee EQ-5D 0.27 vs 0.44, p<0.001, OKS 16.4 vs 21.4, p<0.001). Pre-operative pain was significantly worse in those taking opioids (Hip Pain VAS 42.73 vs 50.70, p<0.001; Knee Pain VAS 50.93 vs 53.36, p=0.30). Post-operatively the THA opiate group had significant improvement in EQ-5D (0.175, p<0.001) and OHS (6.5, p<0.001) but were significantly less improved than opiate naïve patients after adjusting for confounding (EQ-5D 0.10, p<0.001; OHS 3.2, p<0.001). TKA opiate group also had significant improvement in EQ-5D (p<0.001) and OKS (p<0.001) but were significantly less (EQ-5D 0.089, p<0.001; OKS 3.9, p<0.001) than opioid naïve patients.

Pre-operative opiate use was associated with significantly worse pre-operative QoL, joint specific function and worse subjective pain. Post-operatively, the opiate group had significantly lower improvement in their QoL and joint specific function.

Whilst emergency fasciotomy for acute compartment syndrome (ACS) of the leg is limb and potentially lifesaving, there remains a perception that such surgery may result in excessive morbidity, which may deter surgeons in providing expeditious care. There are limited long-term studies reporting on the morbidity associated with fasciotomy.

A total of 559 patients with a tibial diaphyseal fracture were managed at our centre over a 7-year period (2009–2016). Of these patients, 41 (7.3%) underwent fasciotomies for the treatment of ACS. A matched cohort of 185 patients who did not develop ACS were used as controls. The primary short-term outcome measure was the development of any complication. The primary long-term outcome measure was the patient reported EQ-5D.

There was no significant difference between fasciotomy and non-fasciotomy groups in the overall rate of infection (17% vs 9.2% respectively; p=0.138), deep infection (4.9% vs 3.8%; p=0.668) or non-union (4.9% vs 7.0%; p=1.000). There were 11 (26.8%) patients who required skin grafting of fasciotomy wounds. There were 206 patients (21 ACS) with long-term outcome data at a mean of 5 years (1–9). There was no significant difference between groups in terms of the EQ-5D (p=0.81), Oxford Knee Score (p=0.239) or the Manchester-Oxford Foot Questionnaire (p=0.629). Patient satisfaction on a linear analogue scale was reduced in patients who developed ACS (77 vs 88; p=0.039).

These data suggest that when managed with urgent decompressive fasciotomies, ACS does not appear to have a significant impact on the long-term patient reported outcome, although overall patient satisfaction is reduced.

Successful return to work (RTW) is a crucial outcome after primary total knee arthroplasty (TKA) in patients under 65 years old. We aimed to determine whether TKA facilitated RTW in patients <65 years, whose intention was to return preoperatively.

We prospectively assessed 106 TKA patients under 65 years over a 1 year period both preoperatively and at 1 year following surgery. Patient demographics were collected including Oxford knee score, Oxford-APQ, VAS pain/health scores and EQ-5D. A novel questionnaire was distributed to delineate pre-operative employment status and post-operative intentions. This included questions on nature of pre and post-operative occupation, whether joint disease affected their ability to work and details of retirement plans and how this was affected by their knee.

69 patients intended to return to work following their TKA. Following arthroplasty, 57/69 patients (82.6%) returned to work at a mean of 16.4 weeks (SD 16.6). Univariate analysis showed significant factors facilitating RTW included, pre-operative oxford knee score, pre-operative Oxford-APQ score and pre-operative EQ-5D score. These were not predictive on multivariate analysis.

This study finds that TKA facilitates return to work in 83% of those who intend to return to work following their surgery. This could have significant positive and health and financial cost implications for the individual, health system and society.

To evaluate if clinical recovery following midshaft clavicle fracture is associated with nonunion and determine if this has superior predictive value compared to estimation at time of injury.

A prospective study of all patients (≥16 years) who sustained a displaced midshaft clavicle fracture was performed. We assessed patient demographics, injury factors, functional scores and radiographic predictors with a standardized protocol at six-weeks. Conditional-stepwise regression was used to assess which factors independently predicted nonunion at six-months post-injury determined by CT. The nonunion predictor six-week model (NUP6) was compared against a previously validated model based on factors available at time of injury (NUP0-smoking, comminution and fracture displacement).

200 patients completed follow-up at six months. The nonunion rate was 14% (27/200). Of the functional scores, the QuickDASH had the highest accuracy on receiver-operator-characteristic (ROC) curve analysis with a 39.8 threshold, above which was associated with nonunion (Area Under Curve (AUC) 76.8%, p<0.001).

On regression modelling QuickDASH ≥40 (p=0.001), no callus on radiograph (p=0.004) and fracture movement on examination (p=0.001) were significant predictors of nonunion. If none were present the predicted nonunion risk was 3%, found in 40% of the cohort (n=80/200). Conversely if two or more were present, found in 23.5% of the cohort, the predicted nonunion risk was 60%.

The NUP6 model appeared to have superior accuracy when compared to the NUP0 model on ROC curve analysis (AUC 87.3% vs 64.8% respectively).

Delayed assessment at six-weeks following displaced clavicle fracture enables a more accurate prediction of fracture healing.

The aim of our study was to compare the incidence of post-operative anterior knee discomfort after anterograde tibial nailing by suprapatellar and infrapatellar approaches.

95 subjects presenting with a tibial fracture requiring an intramedullary nail were randomised to treatment using a suprapatellar (SP) or infrapatellar (IP) approach. Anterior knee discomfort was assessed at 4 months, 6 months and 1 year post operatively using the Aberdeen Weightbearing Test-Knee (AWT-K), knee specific patient reported outcome measures and the VAS pain score. The AWT-K is an objective measure which uses weight transmitted through the knee when kneeling as a surrogate for anterior knee discomfort.

53 patients were randomised to an SP approach and 42 to an IP approach. AWT-K results showed a greater mean proportion of weight transmitted through the injured leg compared to the uninjured leg when kneeling in the SP group compared to the IP group at all time points at all follow-up visits. This reached significance at 4 months for all time points except 30 seconds. It also reached significance at 6 months at 0 seconds and 1 year at 60 seconds.

We conclude that the SP approach for anterograde tibial nailing reduces anterior knee discomfort post operatively compared to the IP approach.

Anterior knee pain (AKP) is the commonest complication of total knee arthroplasty (TKA). This study aims to assess whether sagittal femoral component position is an independent predictor of AKP after cruciate retaining single radius TKA without primary patellofemoral resurfacing.

From a prospective cohort of 297 consecutive TKAs, 73 (25%) patients reported AKP and 89 (30%) reported no pain at 10 years. Patients were assessed pre-operatively and at 1, 5 and 10 years using the short form 12 and Oxford Knee Score (OKS). Variables assessed included demographic data, indication, reoperation, patella resurfacing, and radiographic criteria.

Patients with AKP (mean age 67.0 (38–82), 48 (66%) female) had mean Visual Analogue Scale (VAS) Pain scores of 34.3 (range 5–100). VAS scores were 0 in patients with no pain (mean age 66.5 (41–82), 60 (67%) female). Femoral component flexion (FCF), anterior femoral offset ratio, and medial proximal tibial angle all differed significantly between patients with AKP and no pain (p<0.001), p=0.007, p=0.009, respectively). All PROMs were worse in the AKP group at 10 years (p<0.05). OKSs were worse from 1 year (p<0.05). Multivariate analysis confirmed FCF and Insall ratio <0.8 as independent predictors of AKP (R² = 0.263). Extension of ≥0.5° predicted AKP with 87% sensitivity.

AKP affects 25% of patients following single radius cruciate retaining TKA, resulting in inferior patient-reported outcome measures at 10 years. Sagittal plane positioning and alignment of the femoral component are important determinants of long-term AKP with femoral component extension being a major risk factor.

The primary aim of this study was to compare the knee specific functional outcome of partial compared with total knee replacement (TKR) for the management of patellofemoral osteoarthritis.

Fifty-four consecutive Avon patellofemoral replacements were identified and propensity score matched to a group of 54 patients undergoing a TKR with patella resurfacing for patellofemoral osteoarthritis. The Oxford knee score (OKS), the Short Form (SF-) 12 and patient satisfaction were collected (mean follow up 9.2 years). Survival was defined by revision or intention to revise.

There was no significant difference in the OKS (p>0.60) or SF-12 (p>0.28) between the groups. The TKR group was significantly less likely to be satisfied with their knee (95.1% versus 78.3%, OR 0.18, p=0.03). Length of stay was significantly (p=0.008) shorter for the Avon group (difference 1.8 days, 95% CI 0.4 to 3.2). The 10 year survival for the Avon group was 92.3% (95% CI 87.1 to 97.5) and for the TKR group was 100% (95% CI 93.8 to 100). There was no statistical difference in the survival rate (Log Rank p=0.10).

The Avon patellofemoral replacement have a shorter length of stay with a functional outcome and satisfaction rate that is equal to that of TKR. The benefits of the Avon need to be balanced against the increased rate of revision when compared with TKR.

The optimal approach for total hip arthroplasty (THA) remains controversial. We present the results of the Direct Superior Approach (DSA), an improved variation of the posterior approach with high levels of stability, patient-reported functional outcomes, and satisfaction.

This is a single-surgeon prospective series. All patients undergoing THA between 2010 and 2015 via the DSA were included. Complication data was collected by interrogation of the Scottish Arthroplasty Project national joint registry. Pre and one-year post-operative Oxford Hip Score (OHS), Euroqol-5D (EQ-5D), and patient satisfaction questionnaires were collected.

659 patients received a THA via the DSA during the study period. Average age was 61.8 years (range 16.4–93.3). Analysis of registry data revealed no cases of dislocation, 5 cases of venous thromboembolism (0.75%), and 5 cases of deep infection (0.75%). 586 patients (88.9%) underwent their surgery in the National Health Service, and post-operative outcomes were available for 337 of these patients (57.5% follow-up) at one year. Average improvement in OHS and EQ-5D was 20 (range −14 – 48) and 0.39 (−0.697–1.2) respectively. 311 patients (92.3%) were satisfied.

This description of the DSA is accessible to all surgeons, confers excellent stability with no dislocations, and is associated with excellent post-operative functional outcomes and patient satisfaction.

Patient reported outcomes and satisfaction scores following excision of interdigital Morton's neuroma have been recently established. However, little is known regarding what patient factors affect these outcomes. This is the first and largest prospective study to determine which patient factors influence surgical outcome following Morton's neuroma excision.

Over a seven-year period, 99 consecutive patients (112 feet) undergoing surgical excision of Morton's neuroma were prospectively studied. 78 patients were female with a mean age at operation of 56 years. Patient recorded outcomes and satisfaction were measured using the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12 (SF12) and a supplementary patient satisfaction survey three months pre and six months post-operatively. Patient demographics were recorded in addition to co-morbidities, deprivation, associated neuroma excision and other forefoot surgery.

Obesity, deprivation and revision surgery proved to statistically worsen MOXFQ outcomes post-operatively (p=0.005, p=0.002 and p=0.004 respectively). Deprivation significantly worsened the mental component of the SF12 (p=0.043) and depression the physical component (p=0.026). No difference in outcome was identified for age, sex, time from diagnosis to surgery, multiple neuroma excision and other forefoot surgeries. 23.5percnt; of deprived patients were dissatisfied with their surgery compared to 7percnt; of the remaining cohort.

Patient reported outcomes following resection of symptomatic Morton's neuroma are shown to be less favourable in those patients who display characteristics of obesity, depression, deprivation and in those who undertake revision neuroma resection. Surgery can be safely delayed, as time to surgery from diagnosis bears no impact on clinical outcome.

Aims

To evaluate the outcomes of cemented total hip arthroplasty (THA) following a fracture of the acetabulum, with evaluation of risk factors and comparison with a patient group with no history of fracture.

Risk of revision following total knee replacement is relatively high in patients under 55 years of age, but little is reported regarding non-revision outcomes. This study aims to identify predictors of dissatisfaction following TKR in patients younger than 55 years of age.

We assessed 177 TKRs (157 consecutive patients) from 2008 to 2013. Data was collected on age, sex, implant, indication, BMI, social deprivation, range of motion, and prior knee surgery in addition to Oxford Knee Score (OKS) and SF-12 score. Postoperative data included knee range of motion, complications, and OKS, SF-12 score and satisfaction measures at one year.

Overall, 24.9% of patients (44/177) were unsure or dissatisfied with their TKR. Significant predictors of dissatisfaction on univariable analysis (p<0.05) included: Kellgren-Lawrence grade 1/2 osteoarthritis; indication; poor preoperative OKS; postoperative complications; and poor improvements in OKS and pain component score (PCS) of the SF-12. Odds ratios for dissatisfaction by indication compared to primary OA: OA with previous meniscectomy 2.86; OA in multiply operated knee 2.94; OA with other knee surgery 1.7; OA with BMI>40kgm-2 2; OA post-fracture 3.3; and inflammatory arthropathy 0.23. Multivariable analysis showed poor preoperative OKS, poor improvement in OKS and postoperative stiffness, particularly flexion of <90°, independently predicted dissatisfaction (p<0.005).

Patients coming to TKR when under 55 years of age differ from the ‘average’ arthroplasty population, often having complex knee histories and indications for surgery, and an elevated risk of dissatisfaction.

This study assessed whether patient satisfaction with their hospital stay influences the early outcome of total knee replacement (TKR).

During a five year period patients undergoing primary TKR at the study centre had prospectively outcome data recorded (n=2264). Patients with depression (p=0.04) and worse mental wellbeing (p<0.001), according to the short form (SF)-12, were more likely to be dissatisfied with their hospital stay. Decreasing level of satisfaction with their hospital stay was associated with a significantly worse post-operative OKS (p<0.001) and SF-12 score (p<0.001). Multivariable regression analysis confirmed that the patients perceived level of satisfaction with their hospital stay was an independent predictor of change in the OKS (p<0.001) and SF-12 score (p<0.001) after adjusting for confounding variables. Patient satisfaction with their TKR was significantly influenced by their hospital experience, decreasing from 96% in those with an excellent experience to 42% in those with a poor experience. Food, staff/care, and the hospital environment were the most frequent reasons of why patients rated their hospital experience as fair or poor.

A patient's perception of their inpatient hospital experience after surgery is an important modifiable predictor of early functional outcome and satisfaction with TKR.

Current knowledge regarding outcomes following surgical treatment of Morton's neuroma remains incomplete. This is the first prospective study to report the pre- and post-operative patient reported outcomes and satisfaction scores following excision of interdigital Morton's neuroma.

Over a seven year period, 99 consecutive patients (112 feet) undergoing surgical excision of Morton's neuroma were prospectively studied. 78 patients were female with a mean age at operation of 56 years. Patient recorded outcomes and satisfaction were measured using the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12 (SF12) and a supplementary patient satisfaction survey three months pre and six months post-operatively.

Statistically significant differences were found between the mean pre- and post-operative MOXFQ and physical component of the SF-12 (p<0.05). No difference in outcome was identified in patients in whom multiple neuromas were operated compared to single site surgery. However, revision surgery proved to statistically worsen MOXFQ outcomes post-operatively p<0.004. Overall satisfaction was reported as excellent (49%) or good (29%) by the majority of patients but 10% were dissatisfied with poor (8%) or very poor (2%) results expressed. Only 64% were pain free at the time of follow-up and 8% of patients MOXFQ scores worsened.

These findings illustrate that overall, patient reported outcomes following resection of symptomatic Morton's neuroma are acceptable but may not be as favourable as earlier studies suggest. Caution should be taken when considering revision surgery which has shown to be a poor prognostic indicator. Contrary to current knowledge, multiple site surgery can be safely undertaken.

Many psychological factors have been associated with function after joint replacement. Personality is a stable pattern of responses to external conditions and stimuli. The aim of this study was to investigate the relationship between personality, joint function, and general physical in patients undergoing total hip (THR) and knee replacement (TKR).

We undertook a prospective cohort study of 184 patients undergoing THA and 205 undergoing TKA. Personality was assesed using the Eysneck Personality Questionaire, brief version (EPQ-BV). Physical health was measured using the EuroQol (EQ-5D). Joint function was measured using the relevant Oxford Score. Outcomes were assessed at six months. Multivariable models were constructed.

The stable introvert personality was most common. Unstable introverts had poorer pre-operative function with hip arthrosis, but not knee arthrosis. Personality was not directly associated with post-operative function – the only independent predictors were pre-operative function (p=0.002) and comorbidity (p<0.001). While satisfaction after TKR was associated with personality (p=0.026), there was no association after THR (p=0.453). The poorest satisfaction was in those with the unstable introvert personality type.

Personality was a predictor of preoperative status. It did not have a direct association with postoperative status, but may have as preoperative function was the main predictor of postoperative function, personality may have had an indirect effect. Personality was also a predictor of satisfaction after TKR. This suggests that predicting satisfaction after knee replacement is more complex. Therefore certain patient may benefit from a tailored preoperative education to explore and manage expectations.

Expectations of patients requiring knee arthroplasty surgery have become higher than in the past, with more strain being put on modern prostheses by fitter and younger patients. The objective of this study was to analyse the survivorship of primary knee arthroplasties at a minimum of ten years, with end points of revision and death. Patients who had a total (TKA) or unicompartmental (UKA) knee arthroplasty performed at a university teaching hospital were identified from the local arthroplasty database. Electronic and operative records were analysed to determine parameters including operative indication, subsequent revision surgery, and patient mortality. Results were collated and analysed using PASW software.

A total of 1023 patients were recruited, with 566 (55%) female and 457 (45%) male. Minimum follow up was 10.1 years, with an average of 12.1 years (S.D 0.87). 64.9% of patients were alive at follow up, with an average age of 79.7 years (S.D 8.7). 92.8% were operated on for osteoarthritis (OA), 6.6% for rheumatoid arthritis (RA) and 0.6% for other indications. Kaplan–Meier analysis estimated survival of 94% (S.D 0.008) at eleven years, with no statistical difference found in survivorship of knees operated on for OA or RA. Similarly no statistical difference was found between survivorship of UKA or TKA implants. Of those that died by follow up, 95.2% did so with their original implant.

We conclude that both TKA and UKA offer a lasting solution for patients, with excellent outcomes achieved in both rheumatoid and osteoarthritic patients.

Nerve damage is a complication of THA and TKA procedures. The incidence of subclinical nerve injury following arthroplasty is unknown. The aim was to determine the prevalence of asymptomatic nerve deficits in an arthroplasty population group, and the incidence of post-operative changes in nerve function. A Secondary aim was to identify the nature of any deficits. And the association between nerve deficits and history of backache.

A non-randomised prospective series of patients undergoing lower limb arthroplasty for osteoarthritis were studied at a single hospital. The peroneal nerve was investigated using nerve conduction in forty patients. Twenty patients had upper limb testing to differentiate between a polyneuropathy or isolated lower limb neuropathy.

Nerve function deficits were detected in the peroneal nerve in fifteen patients pre-operatively and fifteen post-operatively, of those twelve had A waves detected suggestive of a generalised neuropathy. Ten patients who had upper limb testing had a conduction defect (five had asymptomatic Carpal tunnel). There was a positive correlation between presence of post-operative deficit and age(r=0.389, p=0.013). A negative correlation was found for presence of post-operative A waves and BMI(r=−0.370, p=0.019).

The prevalence of pre-operative subclinical peroneal neuropathy is much higher than expected in this group (37.5%) of arthroplasty patients. There is a strong correlation between presence of post-operative conduction abnormalities and age. There is no relationship between peripheral neuropathy and history of backache or residual post-operative deficit.

We reviewed the outcome of Agility total ankle replacements carried out in our institution between 2002 and 2006.

Follow-up consisted of clinical and radiological review pre-operatively, at 6 weeks, 6 and 12 months, and annually until 10 years post-op. Clinical review included the American Orthopaedic Foot and Ankle Score, satisfaction and pain scores.

30 arthroplasties were performed in 30 consecutive patients. Pre-operative diagnosis was rheumatoid arthritis (16), primary osteoarthritis (12) and post-traumatic osteoarthritis (2). After a mean follow up of 6.2 years (1.4–10.1), 4 patients had died, and 20 out of the remaining 24 were available for follow-up. Complications included lateral malleoli fracture (3), superficial peroneal nerve injury (2), one early death, unrelated to the surgical procedure, delayed syndesmotic union (1), non-union (6) and deep infection (2), of which one underwent removal of the implant; the other receives long-term oral antibiotics. AOFAS scores improved from mean 40.4 pre-op to 83.5 post-op (p<0.001). Radiological assessment revealed 25 (93%) patients had lucency in at least one zone in the AP radiograph.

We found a relatively high level of re-surgery and complications following Agility total ankle replacement. A 7% revision rate is much higher than would be tolerated in knee or hip arthroplasty, but compares favourably to other studies of TAR. Despite radiological loosening, and the high rate of re-surgery and complications; patients are generally satisfied with the procedure, reporting lower levels of pain and improved function. Overall, we feel that the Agility ankle is an acceptable alternative to arthrodesis, however patients should be warned of the risk of re-surgery

Unicompartmental knee replacements (UKRs) have inconsistent and variable survivorships reported in the literature. It has been suggested that many are revised for ongoing pain with no other mode of failure identified. Using a medial UKR with an all-polyethylene non-congruent tibial component from 2004–7, we noted a revision rate of 9/98 cases (9.2%) at a mean of 39 months. Subchondral sclerosis was noted under the tibial component in 3/9 revisions with well fixed implants, and the aim of this study was to investigate this as a mode of failure. 89 UKRs in 77 patients were investigated radiographically (at mean 50 months) and with SF-12 and Oxford Knee scores at mean follow up 55 months. Subjectively 23/89 cases (25%) had sclerosis under the tibial component. We describe a method of quantifying this sclerosis as a greyscale ratio (GSR), which was significantly correlated with presence/absence of sclerosis (p<0.001). Significant predictors of elevated GSR (increasing sclerosis) were female sex (p<0.001) and elevated BMI (P=0.010) on both univariate and multivariate analysis. In turn, elevated GSR was significantly associated with poorer improvement in OKS (p<0.05) at the time of final follow up. We hypothesise that this sclerosis results from repetitive microfracture and adaptive remodelling in the proximal tibia due to increased strain. Finite element analysis is required to investigate this further, but we suggest caution should be employed when considering all polyethylene UKR implants in older women and in those with BMI >35.