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Volume 95-B, Issue SUPP_10 February 2013 Scottish Committee for Orthopaedics and Trauma (SCOT)

E.J. Baird D. Macdonald A. Gilmour C.S. Kumar

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


R. Lawton A. Malhas M. Reidy B. Clift

Methicillin Resistant Staphylococcus Aureus (MRSA) screening has reduced rates of MRSA infection in primary total hip (THR) and total knee (TKR) replacements. There are reports of increasing methicillin resistance (MR) in Coagulase Negative Staphylococci (CNS) causing arthroplasty infections. We examined microbiological results of all 2-stage THR/TKR revisions in Tayside from 2001–2010.

72 revisions in 67 patients were included; 30 THRs and 42 TKRs. Mean ages at revision were 89 and 72 years respectively. Male: female ratio 1.4:1.2-year survivorship for all endpoints: 96% in THRs and 88% in TKRs. 5-year survival: 83% and 84% respectively.

The most common organisms were SA (30%) and CNS (29%). Antibiotic resistance was more common amongst CNS. 72% of CNS were resistant to Methicillin versus 20% of SA. 80% of CNS were resistant to Gentamicin OR Methicillin versus 20% of SA. 32% (8/72 cases or 11% overall) of CNS were resistant to BOTH Gentamicin AND Methicillin, the primary arthroplasty antibiotic prophylaxis in our region, versus 4% of SA.

Harris Hip Scores and Knee Society Scores were lower post primary, prior to symptoms of infection in patients who had MR organisms cultured compared with those who had methicillin sensitive organisms. One-year post revision both groups recovered to similar scores.

Our data suggest MR-CNS cause significantly more arthroplasty infections than MRSA. Patients developing MR infections tend to have poorer post-primary knee and hip scores before symptoms of infection fully develop. 32% of CNS causing arthroplasty infections in our region are resistant to current routine primary antibiotic prophylaxis.


F. Harrold C. Wigderowitz

Shoulder arthroplasty is the treatment of choice for a range of degenerative diseases. However, long term follow-up suggests almost half of patients graded their treatment as unsatisfactory. Component malalignment is thought the most likely cause. The anterior anatomical neck is used as a reference for the osteotomy. The objective of the study was to analyse the cartilage/metaphyseal interface to identify reference points that may recover version accurately.

Twenty-four humeri were scanned using a Microscribe digitiser and surface laser scanner. Modelling software was used to analyse the Cartilage/metaphyseal interface. The retroversion angle was calculated for the normal geometry and for the standard osteotomy. An ideal osteotomy plane was then created for each specimen and the distance from the cartilage/metaphyseal interface determined, identifying points of least deviation. The reference points were used to simulate a new osteotomy for which retroversion was calculated. The novel osteotomy and traditional osteotomy were compared to the normal geometry.

The mean retroversion for the normal geometry was 18.5±9.0 degrees. The mean retroversion for the traditional osteotomy technique was 29.5±10.7 degrees, significantly different from the original (p<0.001). The mean retroversion using the novel osteotomy was 18.9±8.9 degrees and similar to the normal geometry (p=0.528).

The traditional osteotomy resulted in a mean increase in retroversion of 38%. The increase in version may result in eccentric loading at the glenoid and alter rotator cuff balance. The novel osteotomy resulted in more accurate recovery of head geometry and may improve clinical outcome.


A. MacInnes S. Roberts A. Pillai

Plantar fasciitis is thought to be a self limiting condition best treated by conservative measures, but despite this many patients have a prolonged duration of symptoms and for some surgery may be indicated. Partial plantar fascial release is reported to have a short term success rate of up 80%, but anecdotally this was not thought to represent local experience.

An audit of long term patient reported outcomes following surgery was performed. A total of 26 patients (29 feet) were identified retrospectively and case notes were reviewed for each patient. Patients were contacted by letter and invited to complete two validated patient reported outcome score questionnaires (foot and ankle visual analogue scale (VAS) and MOXFQ).

The average age of the patients was 42.4(range 28–61) for males and 46.2 (range 33–60) for female patients, with a female:male ratio of 2.7:1. Preoperative treatments included orthotics (29), steroid injections (23), physiotherapy (21) and cast immobilisation (11). The average duration of treatment prior to surgical intervention was 3.1 years (range 1–5). All patients were reviewed post operatively and discharged from follow up at an average of 31 weeks, at which time 38% remained symptomatic.

We conclude that the results from open partial plantar fascial release are poor and it is a technique of dubious clinical value.


S.A. Aitken N.D. Clement A.D. Duckworth C.M. Court-Brown M.M. McQueen

The relationship between advancing patient age, decreasing bone mineral density and increasing distal radial fracture incidence is well established. Biomechanical and clinical work has shown that the radiographic severity of distal radial fractures is greater in patients with poor bone quality. Between 1991 and 2007, the number of elderly Scots (aged 75 years or more) increased by 18%, and population projections predict a further 82% increase by 2035. This study was conducted to investigate the effect of recent changes in the demographics of our population on the pattern and radiographic severity of distal radial fractures encountered at our institution.

The epidemiology of two distinct series of patients (1991–93; 2007–08) suffering distal radial fractures was compared. The patient and radiographic fracture characteristics known to be predictive of fracture instability and severity were compared using the MacKenney formulae, and a subgroup analysis of distal radial fragility fractures was performed.

The life expectancy of our catchment population has improved since 1991, and we have encountered a larger number of distal radial fractures occurring in older, more active and functionally independent patients. We identified an increase in the proportion of AO type B fractures, particularly in the oldest patient groups. The radiographic severity of distal radial fractures, especially low energy metaphyseal injuries, has increased.

If the current trend in population demographics continues, it seems likely that orthopaedic surgeons will encounter an increasing number of severe distal radial fractures deemed unsuitable for treatment by closed methods.


M.A. Akhtar F.A. Wade

Charlson Index has been found to predict functional outcome, implant survival, mortality, length of hospital stay and resource use after arthroplasty. Obesity can influence the outcome following lower limb arthroplasty. Our aim was to identify if there was a relationship between Charlson index, obesity and disability and whether this relationship had altered in recent years.

Demographic details, Charlson index, BMI, SF-12 and oxford score were recorded prospectively for 88 consecutive patients undergoing lower limb arthroplasty between August 2011 and January 2012(Group B). The results were compared with Charlson index of 92 consecutive patients between August 2005 and March 2006(Group A).

The mean age for Group A was 70 years (range 41–90). 56(61%) were female and 36(39%) male. The mean Carlson index was 3 (range 0–6) and median was 3. The mean age for Group B was 67 years (range 45–91). 53(60%) were female and 35(40%) male. The mean Charlson index was 2.2 (range 0–11) and median was 0. The difference between the groups was statistically significant with a P value of 0.001. The mean BMI for Group B was 31 (range 15–56) and median 30. Thirteen patients (15%) had BMI<25, 29 patients (33%) had BMI between 25–29. 9(Pre-Obese), 23 patients (26%) had BMI between 30–34. 9(Obese-Class 1), 10 patients (11%) had BMI between 35–39. 9(Obese-Class 2)and 13 patients (15%) had BMI>40 (Obese-Class 3). The only difference between group B1(BMI<30) and B2(BMI>30) was of age with a P value of 0.0003 (72 vs 59 years).

The current group had less comorbidity but 85% of patients were overweight or obese. These patients were younger but there was no difference in their health or disability before surgery. The high prevalence of obesity may represent treatment selection of these patients away from waiting list centres. Consideration about the treatment of obesity should be given before lower limb arthroplasty.


A. Malhas M. Reidy B. Clift

Two stage revision for infection is considered the gold standard with a success rate of 80–90%. Overall functional outcomes of these patients are commonly overlooked. There is a trend towards single stage revision to improve functional outcomes.

We examined the functional scores of 2 stage revision for total hip arthroplasty (THR) and total knee arthroplasty (TKR). 72 revisions were identified over 9 years: 30 THR and 42 TKR. Two year survivorship was 96% in THR revision and 88% TKR revision. Five year survival was 83% and 84% respectively. 50 patients (without recurrence of infection) had recorded functional scores at a minimum of 1 year.

The mean Harris-hip score (HHS) of THR was 75 (21 patients) prior to developing symptoms of infection. Once infected, the mean score fell to 46. At 1 year post revision it returned to 77. At 3 years HHS of 78 (12 patients) and at 5 yrs 62 (3 patients).

The mean knee society score (KSS) of TKR was 66 (29 patients) prior to developing symptoms of infection. Once infected, the mean score fell to 34. At 1 year post revision it returned to 73. At 3 years KSS of 76 (16 patients) and at 5 years 62 (10 patients).

We conclude that functional scores of staged revisions of infected THR and TKR return to pre-morbid levels within a year of completing the second stage. Although single stage revision may have a quicker return to function, by 1 year, staged revision has comparable results.


C. Cree P.J. Jenkins J.S. Huntley

There is substantial concern about the state of musculoskeletal knowledge of junior doctors. There are also marked differences in the locomotor curricula of medical schools, raising the possibility that students may be selectively disadvantaged from gaining appropriate knowledge and/or attaining a musculoskeletal career path. The aims of this study were to assess the musculoskeletal knowledge of newly qualified doctors in the south of Scotland, and to compare this between the two medical schools (Glasgow and Edinburgh) that have different locomotor teaching programmes.

All final year medical students, from Glasgow and Edinburgh Universities (n=158 and 221, respectively), attending the compulsory ‘Preparation for Practice’ lecture course immediately after (Glasgow) or before (Edinburgh) final exams, were assessed by the Freedman and Bernstein musculoskeletal examination, previously validated with two different pass-standards: (i) 73.1% (by orthopaedic surgeons), and (ii) 70% (by physicians).

There was a significant difference (Wilcoxon two sample test; p<0.5×10−9) in the marks obtained at the two institutions, the median being 59% (IQR 50–67%) and 68% (IQR 60–76%) at Glasgow and Edinburgh respectively. The pass-rates for the two institutions (Glasgow vs. Edinburgh) were markedly different, being 17.1% vs. 32.6% for the higher pass-mark, and 21.5% vs. 48% for the lower.

The majority of newly qualified doctors in the south of Scotland have inadequate musculoskeletal knowledge. There is a substantial and statistically significant difference in the scores attained by students from two neighbouring medical schools (Glasgow and Edinburgh). The striking difference in the pass-rates can be best explained by differences in respective musculoskeletal courses. These explicit and comparative deficits raise substantial questions for musculoskeletal curriculum planning, teaching, assessment and quality assurance.


C. Elias-Jones J.H. Reilly S. Kerr R.M.D. Meek S. Patil M.P. Kelly L. Campton I.B. McInnes N. Millar

Femoroacetabular impingement (FAI) is a significant cause of osteoarthritis in young active individuals but the pathophysiology remains unclear. Increasing mechanistic studies point toward an inflammatory component in OA. This study aimed to characterise inflammatory cell subtypes in FAI by exploring the phenotype and quantification of inflammatory cells in FAI versus OA samples.

Ten samples of labrum were obtained from patients with FAI (confirmed pathology) during open osteochondroplasty or hip arthroscopy. Control samples of labrum were collected from five patients with osteoarthritis undergoing total hip arthroplasty. Labral biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD202), T cells (CD3), mast cells (mast cell tryptase) and vascular endothelium (CD34).

Labral biopsies obtained from patients with FAI exhibited significantly greater macrophage, mast cell and vascular endothelium expression compared to control samples. The most significant difference was noted in macrophage expression (p<0.01). Further sub typing of macrophages in FAI using CD202 tissue marker revealed and M2 phenotype suggesting that these cells are involved in a regenerate versus a degenerate process. There was a modest but significant correlation between mast cells and CD34 expression (r=0.4, p<0.05) in FAI samples.

We provide evidence for an inflammatory cell infiltrate in femoroacetabular impingement. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate hip impingement. Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early hip impingement.


D.F. Howie G.J. Love A.H. Deakin A.W.G. Kinninmonth

Component malalignment has long been implicated in poor implant survival in Total Knee Arthroplasty (TKA). Malalignment can occur in orientation of bony cuts, and in component cementation/implantation. Several systems exist to aid bony cut alignment (navigation, shape matching), but final implantation technique is common to all TKA. Correction of errors in bony cut alignment at cementation/implantation by surgeons has been described. Changes in alignment at this stage are likely to result in asymmetrical cement penetration, which is implicated in early failure.

This study reviewed a consecutive series of 150 primary cemented TKAs using an imageless navigation system (aiming for neutral overall limb alignment). Deviation at implantation was calculated by comparing limb alignment recorded using the trial components with limb alignment recorded with the final implanted components, prior to closure.

136 patients (91%) had a final overall limb alignment within 2° of neutral. Three patients (2%) had a final overall limb alignment greater than 3° from neutral. Deviation occurring at implantation is shown in Figure 1 with deviations distributed around zero (mode 0, median 0.3, range −2 to +4,)


J M Wohlgemut G Medlock I M Stevenson A J Johnstone

Magnetic resonance imaging (MRI) validation of a novel method of assessing Distal Radial Fracture (DRF) reduction using the hypothesised constant relationship between the dorsal radial cortex (DC) and the superior pole of the lunate (SL).

MRI scans of 28 normal wrists were examined. Scans included the distal third of the radius to the proximal carpal row. Beginning 5cm proximal to the distal radius articular surface, a line was superimposed upon the DC extending distally through the metaphyseal flare.

Lunate height (LH) and distance from the DC line to the SL (DC-SL) were measured at 5-degree rotational increments around the radial shaft central axis to a total of 30 degrees of supination and pronation (S+P). The DC-SL/LH ratio was compared to 0 degrees (anatomical lateral) using the two-tailed paired student t-test.

There was no significant difference in DC-SL:LH between 0 degrees of rotation and any 5-degree increment up to 30 degrees of S+P (lowest p=0.075). The DC line lay consistently dorsal to the SL.

A constant DC-SL relationship exists with up to 30 degrees of S+P. This reference can be quickly and accurately used to assess DRF reduction in poorly-taken films with malrotation up to 30 degrees from anatomical lateral. Research comparing DC-SL distance with volar tilt to assess DRF reduction is needed.


A. Clement K. Baird

A review of current literature describes varying 10-year survival rates for the Oxford Unicompartmental Knee Replacement (Biomet Orthopedics Inc, Warsaw, Ind). Application of rigorous indications and meticulous surgical technique are two factors considered to reduce revision rates.

A retrospective case-note review was conducted for 96 patients (128 knees) aged 42–89 (mean 57) who had an Oxford unicompartmental knee replacement for medial compartment osteoarthritis between January 2000 and January 2011. All procedures were performed, or directly supervised, by one 5 surgeons. The aim of the study was to ascertain the rate of revision to bicompartmental knee replacement and any associated contributory factors.

Of the 128 unicompartmental knees, 10.9% were revised to either mobile- or fixed-bearing total knee replacements due to septic (0.5%) and aseptic (1.5%) loosening, patello-femoral pain (3.9%), periprosthetic fracture (0.8%) and bearing dislocation (3.1%). Of those knees requiring revision, mean patient age was 73 years, 50% had wound complications and 42% were performed by senior trainees. All patients had intact ACL and medial osteoarthritis. Mean time to revision was 2.7 years.

In conclusion, revision of the unicompartmental knee was related to patient age > 65 years and early post-operative complications; grade of operating surgeon had little apparent effect.


R. Venkataraman F. Picard

Post operative warfarinisation of elective arthroplasty patients delays their discharge. We retrospectively analysed all patients who required warfarinisation post surgery from April to September 2011. We identified the number of extra days stayed for the sole purpose of warfarinisation (i.e. after discharge by Physiotherapy and Occupational Therapy) and estimated the cost implications of this extended stay.

76 patients were warfarinised post operation, mean age 70.6 years (50–87) with 42 females and 34 males, 37 THR and 33 TKR.

The mean extra days stayed was 3.1 (range 0 to 9). Atrial fibrillation and previous venous thromboembolism (DVT/PE) were the most common indication, 78%, followed by a current episode of DVT/PE, 11%. The nature of joint replacement made no difference to the extra days stayed (3.1 for THR and 2.9 for TKR) or the INR (2.27 in both groups) at discharge. Random loading dose instead of the recommended 5 mg of warfarin resulted in prolonged stay, 4.5 days compared to 3 days otherwise.

The approximate cost per inpatient day is £500 (£137 nursing, £163 medical and £200 for facilities). From our results this amounts to £1500 per patient and £228,000 a year. In addition, there is a loss of income as the bed occupancy means not being able to undertake another arthroplasty surgery (£3,600 per patient) and possible failure to achieve waiting time targets.

We conclude that substantial financial and resource savings can be made if warfarinisation is undertaken at the community level.


C. Tinning L. Cochrane A. Putti B. Singer

The prevalence of Parkinson's disease (PD) is expected to rise however reports of the outcomes of total knee arthroplasty (TKA) in patients with PD in the literature are sparse. We present the first study to compare short to medium term outcomes of TKA in patients with and without PD.

We performed a retrospective analysis of data from our regional arthroplasty database. In our PD group 32 TKAs were implanted. In our age-matched control group 33 TKAs were implanted. Mean age at operation was 73 years and the primary indication was osteoarthritis in both groups.

Data was collected pre-operatively and at routine 1, 3 and 5 year follow-up attendances. Median in-patient stay was comparable in both groups (P=0.714). Pre-operatively, there were no between-group differences in range of movement, Knee Society Function Score (KSFS), Knee Society Score (KSS) or Pain score taken as an independent variable (P=0.108, 0.079, 0.478 and 0.496). KSS improved in both groups post-operatively with no significant between-group differences (P=0.707). Improvement was maintained to Year 5 (median 30 points pre-operatively and 91 points at Year 5 in PD group). Pain score also improved in both groups. There was no functional improvement following TKA in the PD group. In the controls, an increase in KSFS at Year 1 was followed by a return to pre-operative values at Year 5. Complications in the PD group included 1 case of bilateral quadriceps tendon avulsion and 1 dislocation requiring revision.

Patients with PD benefit from excellent pain relief following TKA for at least 5 years after surgery.


S. L. Gill S. Hussain J. MacLeod D. F. Finlayson

Revision hip surgery is reportedly rising inexorably yet not all units report this phenomenon. The outcome of 1143 consecutive Corin TaperFit primary hip arthroplasties (957 patients) performed between 1995 and 2010 is presented. The implants were cemented under pressurisation and combined the TaperFit stem with Ogee flanged cups.

Data was gathered from local arthroplasty database and case note review of revised joints. 13 hips have been revised (1.1%). Cumulative prosthesis survival is 0.99 +/− 0.0. Two femoral stems were revised (0.2%); one at 6 months for sepsis, one at 14 days after dislodgment during reduction of dislocation. No revisions were undertaken for aseptic loosening of the stem or cup, nor for thigh pain. 32 patients (32 hips) ≥15 year follow up, 13 survive today and none have been revised (0%). Of the 471 with ≥10 year follow up, 38 were aged ≤50 at time of surgery and 1/38 has been revised to date (PLAD for dislocation).

The strong population stability in this region, supported by independent investigation by Scottish Arthroplasty Project, endorses the accuracy of the data quoted. The low incidence of revision in this cohort, and absence of revision for aseptic loosening (mean follow up 8.03 years +/− SD 3.94; range 18 months to 16yrs 2 months), substantially supports the longevity and use of cemented, double-taper, polished, collarless femoral stems in combination with cemented polyethylene cups in primary hip arthroplasty in all patient age groups.


N.D. Clement R. Burnett

There is conflicting data from small retrospective studies as to whether pre-operative mental health influences the outcome of total knee replacement (TKR).

We assessed the effect of mental disability upon the outcome of TKR and whether mental health improves post-operatively. During a three year period patients undergoing TKR for primary osteoarthritis at the study centre had prospectively outcome data recorded (n=962). Pre-operative and one year short-form (SF) 12 scores and Oxford knee scores (OKS) were obtained. The mental component of the SF-12 was stratified into four groups according to level of mental disability (none ≥50, mild 40to49, moderate 30to39, severe <30). Ethical approval was obtained (11/AL/0079).

Patients with any degree of mental disability had a significantly greater subjective physical disability according to the SF-12 (p=0.06) and OKS (p<0.001). Although the improvement in the disease specific score (OKS) was not affected by a patients mental health (p=0.33). In contrast the improvement of the global physical health (SF-12) for patients with a mental disability did not improve to the same magnitude (p<0.001). However, patients with mental disability, of any degree, had a significant improvement in their mental health post-operatively (p<0.0001). Despite the similar improvement in the disease specific scores and improvement in their mental health, patients with mental disability were significantly more likely to be dissatisfied with their TKR at one year (p=0.001).

TKR for patients with poor mental health benefit from improvement in their mental health and in their knee function, but do have a higher rate of dissatisfaction.


I.D.M. Smith K.M. Milto C. Doherty S.G.B. Amyes A.H.R.W. Simpson A.C. Hall

Staphylococcus aureus is a highly virulent pathogen and is implicated in approximately 50% of cases of septic arthritis. Studies investigating other S. aureus-related infections have suggested that alpha (Hla), beta (Hlb) and gamma (Hlg) toxins are key virulence factors. In particular, the ‘pore-forming’ alpha toxin is believed to be most potent. In this study, we have assessed the influence of alpha toxin on in situ chondrocyte viability.

Osteochondral explants were harvested from the metacarpophalangeal joints of 3-year-old cows and placed into flasks containing Dulbecco's Modified Eagle's Medium. The flasks were then inoculated with the following isogenic ‘knockout’ strains of S. aureus: DU5946 (Hla+Hlb-Hlg-) or DU1090 (Hla-Hlb+Hlg+).

The explants were incubated (37°C) and stained after 18, 24 and 40hrs with chloromethylfluorescein di-acetate and propidium iodide, labelling living chondrocytes green and dead cells red, respectively. Axial sections were imaged by confocal microscopy and the percentage cell death obtained using Volocity 4 software.

The alpha toxin-producing S. aureus caused rapid cell death, with 24.8+/−3.7% at 18hrs and 44.6+/−7.2% at 24hrs. At 40hrs, there was significantly more chondrocyte death (87.4+/−3.6%; p<0.001) compared to the alpha toxin knockout strain (4.1+/−1.7%; means +/− SEM; n=4).

In situ chondrocyte viability was significantly compromised by alpha toxin, with beta and gamma toxins having minimal effect. Further work will clarify the exact mechanism through which this important toxin induces chondrocyte death. Thereafter, it is hoped that targeted treatments can be developed to reduce the extent of cartilage destruction during, and after, an episode of septic arthritis.