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Volume 101-B, Issue SUPP_1 January 2019 The Scottish Committee for Orthopaedics and Trauma (SCOT) September 2018 Meeting, Dunblane, Scotland.

S.T.J. Tsang P.J. Gwynne M.P. Gallagher A.H.R.W. Simpson

Staphylococcus aureus is responsible for 60–70% infections of surgical implants and prostheses in Orthopaedic surgery, costing the NHS £120–200 million per annum. Its ability to develop resistance or tolerance to a diverse range of antimicrobial compounds, threatens to halt routine elective implant surgery. One strategy to overcome this problem is to look beyond traditional antimicrobial drug therapies and investigate other treatment modalities. Biophysical modalities, such as ultrasound, are poorly explored, but preliminary work has shown potential benefit, especially when combined with existing antibiotics.

Using a methicillin-sensitive S. aureus reference strain and the dissolvable bead assay, biofilms were challenged by a low-intensity ultrasound (1.5MHz, 30mW/cm2, pulse duration 200µs/1KHz) for 20 minutes and gentamicin. The outcome measures were colony-forming units/mL (CFU/mL) and the minimum biofilm eradication concentration (MBEC) of gentamicin. The mean number of S. aureus within control biofilms was 1.04 × 109 CFU/mL. There was no clinically or statistically significant (p=0.531) reduction in viable S. aureus following ultrasound therapy alone. The MBEC of gentamicin for this S. aureus strain was 256 mg/L. The MBEC of gentamicin with the addition of ultrasound was 64mg/L. Further studies confirmed that the mechanism of action was due to incomplete disruption of the extracellular matrix with subsequent metabolic stimulation of the dormant biofilm-associated bacteria due to increased nutrient availability and oxygen tension.

Low intensity pulsed ultrasound was associated with a 4-fold reduction in the effective biofilm eradication concentration of gentamicin; bringing the MBEC of gentamicin to within clinically achievable concentrations.


P. Stirling E. Goudie D. MacDonald G. Macpherson P. Gaston

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.


L. D. Hughes K. A. Chamberlain A. Sloan Q. Choudry H. Robinson

MHRA guidance for patients with metal on metal hip replacements (MOM) was provided in 2012 and updated in 2017 to assist in the early detection of soft tissue reactions due to metal wear debris. A large number of metal on metal hip replacements were undertaken at our trust. A program of recall for all patients with metal on metal hip replacements was undertaken and MHRA guidelines implemented.

Identification and recall of all patients from 2001 with MOM hip replacements using theatre logs, patient records and consultant log books. Two consultant review of X-rays and patient records. Postal questionnaires and GP requests for cobalt & chromium blood tests. Two consultant led MOM review clinics undertaken with metal artefact reduction scans (MARS) performed following consultation in 2017.

674 patients, 297 available for review. 59 refused follow up. 87 moved out of area, 36 untraceable, 26 not MOM, 147 RIP, 22 already revised. From 297 patients 126 female, 171 male, age range 39 – 95 yrs. 126 resurfacing, 171 MOM THR. 26 patients with elevated metal ions, MARS performed of which 17 positive, 9 negative. Of 17 positive scans 10 patients asymptomatic, 7 waiting revision.

A time consuming effort and additional resource was needed and supported by the trust. From 297 hips 17 positive MARs were identified (5.7%). A new database registry has been developed to track MOM patients, clinics set up for ongoing follow up with radiological protocols for imaging. An arthroplasty advanced nurse practitioner (ANP) is now trained reviewing patients independently.


O. J. F. Keenan N. D. Clement R. Nutton J. F. Keating

The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA).

During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed.

Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more.

The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis.


M. McLean M. Akbar K. McCall S. Kitson L.N.A Crowe1 M. Blyth I Smith B.P. Rooney S. Spencer W.J. Leach L.J. Campton D.S. Gilchrist I.B. McInnes N.L. Millar

Tranexamic acid (TXA) is an anti-fibrinolytic medication commonly used to reduce peri-operative bleeding. Increasingly, topical administration as an intra-articular injection or peri-operative wash is being administered at concentrations between 10–100mg/ml. This study investigated effects of TXA on human periarticular tissues and primary cell cultures using clinically relevant concentrations.

Tendon, synovium and cartilage obtained from routine orthopaedic surgeries were used ex vivo or cultured for in vitro studies using various concentrations of TXA. They were stained with 5-chloromethylfluorescein diacetate and propidium iodide and imaged using confocal microscopy to identify the proportion of live and dead cells. The in vitro effect of TXA on primary cultured tenocytes, synovial like fibroblast (FLS) cells and chondrocytes was investigated using cell viability assays (MTT), fluorescent microscopy and multi-protein apoptotic arrays for cell death.

There was significant (p<0.01) increase in cell death in all tissue treated with 100mg/ml TXA, ex vivo. MTT assays revealed significant (p<0.05) decrease in cell viability following treatment with 50 or 100mg/ml of TXA within 4 hours of all cell types cultured in vitro. Additionally, there was significant (p<0.05) increase in cell apoptosis detected by fluorescent microscopy within 1 hour of exposure to TXA. Furthermore, multi-protein apoptotic arrays detected increased apoptotic proteins within 1 hour of TXA treatment in tenocytes and FLS cells.

Our study provides evidence of TXA cytotoxicity to human peri-articular tissues ex vivo and in vitro at concentrations and durations of treatment routinely used in clinical environments. Clinicians should therefore show caution when considering use of topical TXA administration.


S. Downie B. Clift A. Jariwala S. Gupta A. Mahendra

National guidelines recommend that trauma centres have a designated consultant for managing metastatic bone disease (MBD). No such system exists in Scotland. We compared MBD cases in a trauma hospital to a national bone tumour centre to characterise differences in management and outcome.

Consecutive patients with metastatic proximal femoral lesions referred to a trauma unit and a national sarcoma centre were compared over a seven-year period (minimum follow-up one year).

From Jan 2010-Dec 2016, 195 patients were referred to the trauma unit and 68 to the tumour centre. The trauma unit tended to see older patients (mean 72 vs. 65 years, p<0001) with cancers of poorer prognosis (e.g. 31% 61/195 vs. 13% 9/68 lung primary, p<0.001).

Both units had similar operative rates but patients referred to the tumour centre were more likely to have endoprosthetic reconstruction (EPR 44% tumour vs. 3% trauma centre, p<0.001). Patients with an EPR survived longer than those with other types of fixation (81% 17/21 vs. 31% 35/112 one-year survival, p<0.001). Patients undergoing EPR were more likely to have an isolated metastasis (62% 13/21 vs. 17% 4/24, p<0.001). One patient from each centre had a revision for failed metalwork.

There was a difference in caseload referred to both units, with the tumour centre seeing younger patients with a better prognosis. Patients suitable for endoprostheses were more likely to have isolated metastatic disease and a longer survival after surgery. An MBD pathway is required to ensure such patients are identified and referred for specialist management where appropriate.


I. Cunningham L. Guiot A. Din G. Holt

Deficiency in the gluteus medius and minimus abductor muscles is a well-recognised cause of hip pain and considerable disability. These patients present a management challenge, with no established consensus for surgical intervention. Whiteside in 2012 described a surgical technique for gluteus maximus tendon transfer, with successful outcomes reported. This study is the largest known case series to date of patients undergoing gluteus maximus tendon transfer with clinical and patient reported outcomes measured.

13 consecutive patients were included in the study. All patients had clinical evidence of abductor dysfunction together with MRI evidence of gluteal atrophy and fat infiltration. All patients underwent gluteus maximus transfer with surgery performed according to the procedure described by Whiteside. Patients were followed up with both clinical assessment and patient questionnaires conducted.

Mean age was 69 (range 54–82) with 9 patients (69%) having previous Hardinge approach to the affected hip. 6 patients (46%) reported they were satisfied overall with the procedure and 5 patients (38%) were unsatisfied. 7 patients (54%) had improvements in visual analogue scale of pain and 5 patients (54%) reported overall improvements in function. Mean Oxford Hip Score on follow up was 20/48 (range 5–48) and trendelenberg test was positive in 11 patients (85%). No differentiating variable could be identified between patients with positive and negative outcomes (Assessed Variables: Age, sex, BMI, aetiology and gluteus maximus muscle thickness).

Clinical outcomes were varied following gluteus maximus tendon transfer for chronic hip abductor dysfunction. Results are considerably less promising than pre-existing studies would suggest.


L. Guiot S. Spence H. Bradman A Khan G. Holt

Hip fractures in young adults are rare but represent an important cohort of patients, of which relatively limited data exists. The aim of this study was to evaluate this distinct subgroup of hip fractures from an epidemiological perspective and assess their subsequent outcomes.

Patients aged 18–50 were identified across an 8 year period from a total of 5326 hip fractures. 46 hip fractures met the inclusion criteria and a retrospective case series analysis was conducted.

25/46 (54%) of fractures were intracapsular and 21/46 (46%) were extracapsular. Only 15/46 (33%) of fractures were sustained from a high energy mechanism and 31/46 (67%) low energy. The low energy cohort was significantly more comorbid with a mean Elixhauser comorbidity score of 1.5 compared to the high energy cohort 0.3 (p<0.0005, unpaired t-test). Alcohol excess was the most prevalent comorbidity present in 24% of patients and was a positive predictor in complication (p=0.006, binary regression). Failure of fixation (non-union/avascular necrosis) in displaced intracapsular fractures sustained following low energy trauma managed by internal fixation 5/11 (45%) was markedly higher than the high energy cohort 0/6 (0%). 5 year mortality was 9% for all hip fractures, six times higher than an aged matched cohort of non-hip fractures (p=0.007, Wilcoxon test).

Representing only 0.86% of all hip fractures in the study period, hip fractures in young adults are rare. A clear sub-division of patients is observed between patients with a low and high energy mechanism, both in terms of level of comorbidity and surgical outcome.


N.R. Wickramasinghe J.F. Maempel N.D. Clement A.D. Duckworth J.F. Keating

Limited long term data exists comparing operatively and non-operatively treated Achilles tendon ruptures. A previous randomised controlled trial comparing early outcomes showed a short term advantage for surgery, but there are no long term prospective randomised comparisons. Our aim was to determine whether surgery conferred long term benefits in terms of patient reported outcomes or re-rupture.

64 patients (80%) were followed up with postal questionnaires. Patients were asked to complete the Short Musculoskeletal Function Assessment (SMFA), Achilles Tendon Total Rupture Score (ATRS) and EQ-5D questionnaires, and to report re-ruptures.

32 patients were treated non-operatively and 32 operatively; 59 completed the SMFA and 64 the ATRS and EQ-5D assessments. There was no significant difference in SMFA score (median 1.09, IQR 4.89 in the cast group versus 2.17 and 7.07 in the operative group; p=0.347), ATRS (median 96, IQR 18 versus 93 and 15; p=0.509), EQ-5D Index (median 1.0, IQR 0.163 versus 1.0 and 0.257; p=0.327) and EQ-5D Visual Analogue Score (median score 85, IQR 15 versus 85 and 24; p=0.650). There were 2 re-ruptures in the operative group and 4 in the non-operative group (p=0.067).

This is the first prospective, randomised, long term report comparing operative and non-operative management. At follow up between 13–17 years after injury, patients reported good function and health related quality of life. There was no significant difference in re-rupture rate between the treatment groups.


E. Harris G. Holt

Due to changes in population demographics, the burden of hip fractures in Scotland is expected to rise dramatically over the coming decades. This study aims to establish the future incidence of hip fracture in Scotland in individuals aged 50 and over.

The number of patients admitted to hospital in Scotland with a hip fracture between 1999 and 2016 were ascertained from discharge coding across NHS Scotland. The annual number of hip fractures were categorised to enable gender and age specific hip fracture incidence rates to be calculated. Through static and variable projection methods, the annual hip fracture incidence up to 2035 was forecast and analysed with respect to specific demographics ascertained from population data provided by the National Records of Scotland.

Between 1999 and 2016 the total number of hip fractures in individuals aged 50 and over increased by 11%, from 7,131 to 7,930, equating to an average year-on-year increase of 0.6%. Patients aged over 75 consistently accounted for more than 85% of recorded hip fractures, with females having a higher incidence rate than males across all age groups. A decreasing incidence in females aged over 70 was observed. Using multiple projection methods, the annual number of hip fractures in Scotland is predicted to increase by 55% from 7,930 in 2016, to an average of 12,316 by 2035.

Projection modelling confirms the annual number of hip fractures in Scotland will rise substantially by 2035 with considerable implications for health and social care provision.


N. D. Clement T. A. Howard R. J. Immelman D. MacDonald J. T. Patton G. Lawson R. Burnett

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.


A. MacInnes P. Hutchison G. Singleton F. Harrold

Arthritis of the mid-foot is a common presentation to the foot and ankle clinic, resulting from primary (idiopathic), post-traumatic, or inflammatory joint degeneration. Treatment in the initial stages is conservative, with midfoot fusion regarded as the operative treatment of choice; however there is a paucity of comparative and patient reported data regarding outcomes.

Patient reported outcome measures (PROMS), were prospectively collected from October-2015 to March-2018. Diagnoses were confirmed with image guided injection and initial management was conservative. In total, 66 patients were managed conservatively and 40 treated with mid-foot fusion. MOxFQ (Manchester Oxford Foot Questionnaire) and EQ-5D-3L (Euroqual) PROMS were collected pre-operatively, at 26 weeks and at 52 weeks.

In the operatively managed group, the female:male ratio was 5.7:1, with a mean age of 61 (range 24–80), while in the conservatively managed group, the ratio was 2.1:1 with mean age 63 (range 29–86).

In the surgically managed group, 88.2% of patients reported improvement in symptoms at 26 weeks and 88.9% at 52 weeks. This was greater than the conservatively managed group, in which 40.6% reported improvement at 26 weeks and 33.3% at 52 weeks. Mean MOxFQ improvement in the surgically managed group was +30.7 and +33.9 at 26 and 52 weeks respectively, and in the conservative group, +9.4 and +4.3, at 26 and 52 weeks. Similarly, favourable surgical outcomes were reported across all domains of EQ-5D-3L.

This study has highlighted excellent early outcomes after surgical treatment and may represent promise for those patients for whom conservative management fails.


P. Porter T. Drew G. Arnold W. Wang A. MacInnes G. Nicol

The Pronator Quadratus (PQ) is commonly damaged in the surgical approach to the distal radius during volar plating. This study explored the functional strength of the PQ muscle, 12 months after volar plating of a distal radial fracture.

Testing of treated and contralateral forearms was carried out using a custom-made Torque Measuring Device (TMD) and surface Electromyography (sEMG). To assess both the direct and indirect function of PQ in participants treated with volar plating and compared to the contralateral non-injured forearms. The angle of elbow flexion was varied from 45o, 90o and 135o when measuring forearm pronation. Mean peak torque of the major pronating muscles, PQ and Pronator Teres (PT) was directly measured with the TMD and the indirect activation of the PQ and PT was measured with sEMG.

In total 27 participants were studied. A statistically significant reduction in mean peak pronation torque was observed in the volar plated forearms (P<0.05 SE 0.015, CI 95%). This is unlikely to be of clinical significance as the mean reduction was small (13.43Nm treated v 13.48Nm none treated). Pairwise comparison found no statistically significant reduction in peak torque between 45o, 90o and 135o of elbow flexion. There was an increase in PQ muscle activation at 135o compared to 45o elbow flexion. The converse was identified in PT.

The small but statistically significant difference in mean peak torque in treated and uninjured forearms is unlikely to be of clinical significance and results suggest adequate functional recovery of the PQ after volar plating.


J. Martin C. Murphy J. Gregory R. Aspden A. Riemen F. Saunders

An increased prevalence of osteoarthritis (OA) in post-menopausal women has led to the suggestion that hormonal factors may play a role in the pathogenesis. This study aims to examine if undergoing a hysterectomy, both with retention and removal of ovaries, predisposes women to OA and secondly if the development is influenced by hormone replacement therapy (HRT).

Statistical shape modelling (SSM) is a method of image analysis allowing for detection of subtle shape variation described by landmark points. Through the generation of linearly independent modes of variation, each image can be described in terms of numerical scores. 149 radiographs from female participants of the Osteoarthritis Initiative (OAI) were examined to compare hip morphology in those who had undergone hysterectomies compared to controls.

No differences were observed in BMI, age, height or weight between groups. ANOVA and Games-Howell post-hoc analysis showed that modes 3 and 5 were statistically significant. Lower mode 3 scores were associated with hysterectomy (p=0.019), with narrowing of the femoral neck and increased acetabular coverage. Lower mode 5 scores were associated with hysterectomy and oophorectomy (p=0.049), displaying reduced coverage of the femoral head, superolateral migration of the femoral head and larger greater trochanter. No associations were observed between HRT use and OA.

The subtle morphologic features of hip OA present in only hysterectomised women suggests undergoing a hysterectomy may be a predisposing factor and a clinical consideration. The use of HRT was not observed to influence the development of OA and thus cannot be suggested as a protective measure.