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.

Summary

Nearly one-third of patients in this series with an ACL rupture requiring reconstruction had evidence of MPFL injury. This should be considered when patients are seen, and when MRI scans are reviewed/reported.

When performing total knee replacement (TKR), surgeons must select a size of tibial component tray that most closely matches the anatomy of the proximal tibia. As implants are available in a limited range of sizes, it may be necessary to slightly under or oversize the component. There are concerns overhang could lead to pain from irritation of soft tissues, and underhang could lead to subsidence and failure.

154 TKRs at 1- or 5-year follow up were reviewed prospectively. Oxford Knee Score (OKS), WOMAC and SF-12 was recorded along with pain scores. Scaled radiographs were reviewed and grouped into perfect sizing (78 TKRs, 50.6%), underhang in isolation (48 TKRs, 31.1%), minor overhang 1–3 mm (10 TKRs, 6.49%) or major overhang >3 mm (18 TKRs, 11.7%).

There was no significant difference in the SF-12 (p=0.356), post-operative OKS (p=0.401) or WOMAC (p=0.466) score. For the OKS, there was no difference for the scores collected at 1 year (p=0.176) or at 5 years (p=0.883).

Pre-operative OKS was well matched between the groups (p=0.152). There was no significant difference in the improvement in OKS from pre-operative scores (p=0.662). There was no significant difference in either the OKS or WOMAC pain scores (p=0.237 and 0.542 respectively).

There was no significant association of medial overhang with?medial knee pain (p=1.000) or lateral overhang with lateral knee pain (p=0.569) when compared to the group of patients with a well sized tibial component.

Our results suggest that tibial component overhang or underhang has no detrimental affect on outcome or pain scores. Surgeons should continue to select the tibial component that most closely fits the rim of the proximal tibia while accepting slight overhang if necessary due to the potential longer-term complications of subsidence and premature failure with an undersized tibial tray.

Staged bilateral total knee arthroplasty is performed increasingly frequently but no data has been published comparing the specific outcome for the first knee replacement to that of the second.

Pre-operative and post-operative Oxford Knee Scores (/ 48) were reviewed for each knee in a series of 91 patients undergoing staged bilateral total knee arthroplasty over a 5-year period.

Pre-operative scores for the first total knee arthroplasty were significantly worse with a mean of 14.9 in comparison to 17.0 for the second knee (P=0.0083). While there was no significant difference between the mean post-operative scores for the first knee (37.4) and the second knee (36.6) (P=0.195), the mean improvement was significantly less for the second knee (22.6 points versus 19.6 points) (P=0.0045).

Our results demonstrate that in patients undergoing staged bilateral knee arthroplasty, the second knee replacement is commonly performed at a lower threshold and functional improvement is less than for the first knee. This data will be important to inform the expectations of patients considering proceeding to bilateral knee arthroplasty after previously having undergone a primary total knee replacement.

The long-term clinical and radiological results of 63 uncemented Low Contact Stress (LCS) total knee replacements in 47 patients with rheumatoid arthritis were reviewed. The average age at the time of surgery was 69 years (53–81). At a mean follow up of 22 years (20–25), 12 patients (17 knees) were alive, 27 (36 knees) had died, and 8 patients (10 knees) were lost to follow-up.

Revision was necessary in seven patients (7 knees) (11.1%) at mean 12.1 years following surgery. Four revisions were performed due to meniscal bearing wear, two for collapse of the tibial component, and one for aseptic loosening. Evidence of post-operative infection occurred in two knees (3.2%) within 6 weeks of surgery but resolved with antibiotics. Within the group of deceased patients, five had undergone revision (included in total revisions) but otherwise the primary implant remained in vivo.

For all living patients, the mean Oxford Knee Score (/48) was 30.2 (16–41) at latest follow up at mean 19.5 years (15–24.7) following surgery. Mean active flexion was 105 degrees (90–150) at this time point.

Our recorded survival rate of the uncemented LCS total knee replacements in patients with rheumatoid arthritis was therefore 88.9% at mean 22 years, or worst-case survival of 73.0% if patients lost to follow-up were considered failures. From a review of the literature and as far as we are aware, this study represents the longest follow up of any uncemented knee arthroplasty performed in a cohort of patients with rheumatoid arthritis.

Range of motion (ROM) is a well recognised outcome measure following total knee arthroplasty (TKA). Reduced knee flexion can lead to poor outcome after TKA and therefore identification at an early stage is important as it may provide a window for intervention with targeted physiotherapy, closer follow-up and in resistant cases possible manipulation or arthrolysis. ROM combines both flexion and extension and in contrast to flexion, fewer studies have recognised the importance of a lack of full extension or fixed flexion deformity (FFD) following TKA. A residual FFD can increase energy cost, decrease velocity during ambulation and result in pain with knee scores more likely to be diminished than if knee extension was normal. Recognition and early detection of FFD is therefore important. Methods of assessment include by visual estimation or goniometric measurement of knee flexion angle. While goniometers are inexpensive, easy to use and provide more accurate than visual estimates of angles, they have been shown to exhibit poor inter-observer reliability. Therefore they may not be sensitive enough to consistently identify FFD and therefore distinguish between grading systems based on absolute angular limits. The aim of this study was to investigate the accuracy of standard clinical ROM measurement techniques following TKA and determine their reliability for recognising FFD.

Ethical approval was obtained for this study. Thirty patients who were six weeks following TKA had their knee ROM measured. An infrared (IR) tracking system (±1°accuracy) that had been validated against an electro-goniometer was used to give a “true” measurement of the lower limb sagittal alignment with the knee fully extended and maximally flexed while the patient was supine. The patients were also assessed independently by experienced arthroplasty practitioners using a standardised goniometric measurement technique. For goniometric clinically-measured flexion (Clin_flex) and extension (Clin_ext) linear models were generated using IR-measured flexion and extension (IR_flex and IR_ext), BMI and gender as covariables. Data for extension were categorised in none, moderate and severe postoperative FFD as per Ritter et al. 2007 and agreement in classification between the two methods was assessed using the Kappa statistic.

For the linear models for Clin_flex and Clin_ext neither BMI nor gender were significant variables. Therefore the final models were:

Clin_flex = 0.54 + 0.66∗IR_flex (r²_adj = 0.521)

Clin_ext = 0.23 + 0.50∗IR_ext (r²_adj = 0.247)

The model for Clin_flex showed that the IR and clinical measurements coincided at approximately 90° so that for every 10° increase in flexion above 90° clinical measurement only increased by 7° but for every 10° decrease in flexion below 90° clinical measurement only decreased by 7°. The model for Clin_ext showed that the IR and clinical measurements coincided at approximately 0° so that for every 10° increase in FFD angle, clinical measurement only increased by 5° but if the knee went into hyperextension this would be underestimated by the clinical measure. In identifying FFD there was moderate agreement between the two measurements (κ = 0.44). Clinically nine patients were assessed as having FFD but the IR measurements showed 18 patients having FFD, of which nine patients were not identified clinically.

When assessing knee ROM following joint arthroplasty manual goniometric measurements provided a poor estimate of the range when compared to the “true” angle as measured with a validated IR measurement tool. When the knee was held in maximum flexion there was a tendency to both underestimate and overestimate the true angle. However when the knee was held in extension there was a tendency to underestimate which we believe is important as it would underreport both the frequency and magnitude of FFD. In our study, 18 patients had a moderate FFD as identified by the IR system, only half of which were identified by goniometer measurement alone. Studies of comparisons of both visual and manual goniometry measurements of the knee in maximum flexion with lateral radiographs have shown most errors involved an underestimate of true flexion. It has been concluded that it was safer to underestimate knee flexion angle as it would result in higher pick up rate of cases being performing less well. In contrast however, underestimation while in extension is less desirable as it fails to pick-up FFD which may have benefited from intervention had they been identified. It is known that residual FFD can increase energy cost and decrease velocity during ambulation with pain and functional knee scores more likely to be reduced. Recognition and early detection is therefore important. With the use of more accurate systems to identify and measure FFD, such as the one used for this study may in turn allow more timely treatment and therefore hopefully improved outcomes.

In this study we aimed to identify which anatomical site was the most effective for methicillin resistant staphylococcus aureus (MRSA) detection within an elective orthopaedic setting. A retrospective review was performed of 13,373 elective orthopaedic patients from pre-assessment and admission screening swabs taken over a five year period (2005-2010). Swabs were taken from the nose, the axilla and either the groin or perineum. MRSA was identified in 136(1.02%) of patients. The nose was found to be positive for MRSA in 89.6% of cases identified. Therefore only 10.4% of the MRSA carriers (0.1% of all admissions) would not have been identified had a single nasal swab been taken. There was no additional benefit in swabbing the axilla. We believe that for the majority of orthopaedic elective admissions a single nasal swab should be sufficient. In hip arthroplasty patients it may be beneficial to additionally swab the groin given the close proximity of the surgical wound.

Fragility fractures are an increasing cause of morbidity and mortality in the elderly population. Their association with reduced bone mineral density (BMD) is well documented. It is a reasonable assumption that hip fracture severity is linked to the magnitude of bone loss, (the lower the BMD, the more severe the fracture), however it is not known whether this correlation exists. Our aim therefore was to investigate the relationship between BMD and hip fracture severity.

We reviewed 142 patients, 96 females and 46 males, mean age 74 years (49-92), who had sustained a hip fracture following a simple ground level fall. All had subsequently undergone DEXA bone scanning of the contralateral hip and lumbar spine. Fractures were classified as intra-capsular, extra-capsular or subtrochanteric, then sub-classified using the Garden, Jensen and Seinsheimer classifications respectively. They were grouped into simple (stable) or comminuted (unstable) fracture patterns. Risk factors for osteoporosis were recorded.

A low hip BMD (<2.5) was associated with an increased risk of extra-capsular fracture (p=0.025). However, no association with fracture type (extra vs. intra-capsular, p>0.05) was identified with the following variables; age, gender, BMI <25, smoking, and excess alcohol intake. We did not find any statistically significant associations between fracture severity and the nine principle variables tested for: age; gender; smoking; BMI < 25; alcohol excess and low hip or lumbar BMD T or Z score <-2.5.

Although the association between BMD and risk of fragility fractures is well documented, the results of this study would suggest that severity of hip fractures does not follow this correlation. Therefore, no assumption can be made about BMD of the proximal femur based on the severity of fracture observed on plain radiographs alone.

Range of motion (ROM) is a well recognised outcome measure following TKA and combines both knee flexion and extension. In contrast to achieved flexion, fewer studies have recognised the importance of fixed flexion deformity (FFD). A post-operative FFD can adversely affect pain and functional knee scores and so its detection is important. The aim of this study was to investigate the accuracy of standard clinical ROM measurement techniques following TKA and determine their reliability for recognising FFD.

Thirty patients six weeks post-TKA had knee ROM measurements performed with an infrared (IR) tracking system of ±1 accuracy. The patients were also assessed independently by experienced arthroplasty practitioners using a standardised goniometric measurement technique. For goniometric clinically-measured flexion (Clin_flex) and extension (Clin_ext) linear models were generated using IR-measured flexion and extension (IR_flex and IR_ext), BMI and gender as covariables. Data for extension was categorised as FFD present or absent based on Ritter's criteria and agreement was assessed using Kappa.

For both models neither BMI nor gender were significant variables. Models were Clin_flex = 0.54 + 0.66∗IR_flex (r²_adj=0.521) and Clin_ext = 0.23 + 0.50∗IR_ext (r²_adj=0.247), showing that for every 10° increase in flexion, clinical measurement only increased by 7° and for every 10° increase in FFD angle, clinical measurement only increased by 5°. In identifying FFD there was moderate agreement between the two measurements (κ=0.44) with disagreement for nine patients all being patients with FFD that were not identified clinically.

For both flexion and extension there was a greater tendency for the goniometric clinical measurements to underestimate the actual angle. In the context of TKA outcome for maximum flexion this may be preferable to overestimating. In contrast, underestimating the degree of flexion when the knee is in the extended position is not desirable as it will potentially underreport the frequency and magnitude of FFD.

Assessment of coronal knee laxity via manual stress testing is commonly performed during joint examination. While it is generally accepted that the knee should be flexed slightly to assess its collateral restraints, the importance of the exact degree of flexion at time of testing has not been documented. The aim of this study therefore was to assess the effect of differing degrees of knee flexion on the magnitude of coronal deflection observed during collateral stress testing.

Using non-invasive infrared technology, the real-time coronal and sagittal mechanical femorotibial (MFT) angles of three asymptomatic volunteers were measured. A single examiner, blinded to the real-time display of coronal but not sagittal alignment, held the knee in maximum extension and performed manual varus and valgus stress manoeuvres to a perceived end-point. This sequence was repeated at 5° increments up to 30° of flexion. This provided unstressed, varus and valgus coronal alignment measurements as well as overall envelope of laxity (valgus angle – varus angle) which were subsequently regressed against knee flexion.

Regression analysis indicated that all regression coefficients were significantly different to zero (p < 0.001). With increasing knee flexion, valgus MFT angles became more valgus and varus MFT angles became more. The overall laxity of the knee in the coronal plane increased approximately fourfold with 30° of knee flexion.

The results demonstrated that small changes in knee flexion could result in significant changes in coronal knee laxity, an observation which has important clinical relevance and applications. For example the assessment of medial collateral ligament (MCL) injuries can be based on the perceived amount of joint opening with no reference made to knee flexion at time of assessment. Therefore, close attention should be paid to the flexion angle of the knee during stress testing in order to achieve a reliable and reproducible assessment.

Discitis in childhood is rare. It can be difficult to diagnose, particularly in the younger child, often leading to a delay in initiation of appropriate treatment. It is not known whether it represents an infective or an inflammatory process.

Our aim was to review all cases treated at a regional children's hospital since the introduction of the departmental database. A retrospective review (64,058 cases), for the period 1990-2008 was performed. 12 cases were identified (3 male/9 female), with a biphasic age distribution; eight [mean 22 months old (12-32)] and four [mean 12 years old (11-13)]. Mean time to diagnosis from onset was 22 days, (5-49). Symptoms varied with age, no one less than 28 months complained of back pain, while all over 28 months did, to a varying degree. All the younger children presented primarily with a gait abnormality. 92% (11/12) were apyrexial on admission. WBC and CRP were normal in 83% (10/12). Venous blood cultures were negative in 89% (8/9). Only ESR was mildly raised, mean 30 (10-65). Radiographs showed loss of intervertebral disc height in 91% (10/11), earliest by 10 days following onset symptoms, mean 28 days. A technetium bone scan was performed in 42% (5/12) and an MRI of the lumbar spine, in 58% (7/12). All were positive for discitis. All occurred in the lumbar spine, 50% at L3/4. Antibiotics were used in 11/12 (92%), flucloxacillin alone in the majority 9/11. One had non-steroidal medication alone. No form of brace was used. Mean follow-up was 13.3 months (2-36). In all, symptoms had resolved by mean 6.5 weeks (2-12). No recurrence was noted.

The common features of childhood discitis are presented; knowledge of these may aid the physician to come to a more rapid diagnosis of this uncommon paediatric condition.

Objective: To ascertain the epidemiology of ankle injuries in elite youth football.

Design: Retrospective analysis of prospectively collected injury data from English Football Association Academies.

Setting: Forty-one FA Football Academies, between 1998 and 2006.

Participants: For the complete seasons studied, a total of 14776 players were registered from U9 to the U16 age category – a mean of 2463 players per year. All ankle injuries of sufficient severity to miss 48 hours or more training were studied – 2563 injuries in total.

Main outcome measurements: The incidence and burden of ankle injuries in this population, and factors associated with injury.

Results: There was a mean incidence of one ankle injury per player per year, and a mean of 20 training days and 2 matches were missed per ankle injury. Increased injury rates were seen in older players, in competition and later in each half of match time. Peaks in injury were observed early in the season and after the winter break. In competition, more injuries were associated with a contact situation than in training. Eighty-eight injuries (3.4%) required a lay-off of three months or more and in 18 (0.7%) cases, the player failed to return to training. In total, 52290 training days and 5182 match appearances were lost through ankle injury. The majority of injuries were sprains, but more severe injuries occurred accounted for 3.9% of the total.

Conclusions: Ankle injuries are common in young football players, and are often severe, with prolonged loss of training time. This has potential far reaching implications, both on and off the field. Further syudy in this area is suggested.

Introduction: The ideal acetabular component has low wear, permanent fixation and physiological bone loading. Recently trabecular metal has been promoted as reproducing the modulus of trabecular bone with a cementless fixation. The aim of this trial was to see if a monobloc trabecular backed polyethylene acetabular component loaded the pelvis physiologically as a cemented polyethylene component.

Method: Between 2004 and 2006 54 patients were ran-domised to a cemented polyethylene acetabular component versus a monobloc trabecular backed polyethylene acetabular component. The primary outcome measurement was bone density in peri-prosthetic acetabular regions of interest measured preoperatively and post operatively at 6 weeks and 1 year. Secondary outcomes measured were radiographic and functional outcomes (HHS and Oxford score).

Results: Radiographically 8 patients in the trabecular group had a significant gap in zone II which resolved in 6 by 1 year. The cemented group had 3 patients with a radiolucent line (zone 1) at 1 year. HHS and OXFORD scores improved with no significant difference between the groups. Both groups had significant loss of bone density in the ilium and ischium. The trabecular group produced a significant increase in bone density in the superolateral region. The cemented group produced increased bone density in the superomedial region.

Discussions and Conclusions: There is a significant reduction in BMD for both groups in the upper pelvis and ischium in keeping with finite element modelling predictions. The press-fit group relative to the cemented group resulted in decreased BMD in the superomedial peri-prosthetic region. The trabecular monobloc cup therefore behaves more like a rigid cementless shell despite the properties of trabecular metal.

Introduction: Hip resurfacing is a popular alternative to total hip arthroplasty. It aims to provide more physiological loading of the proximal femur, avoiding stress shielding and associated bone resorption. However, finite element analysis of hip resurfacing systems suggests stress shielding occurs in the femoral neck below the prosthesis and theoretically may lead to femoral neck fracture. Nevertheless, recent DEXA studies indicate femoral bone stock preservation with no evidence of stress shielding. It is not yet known what actually occurs in clinical practice. The aim of this study was to assess whether femoral neck resorption occurs in one particular type of hip resurfacing post operatively and quantify the degree of narrowing.

Methods: Femoral neck resorption of the Cormet 2000 metal-on-metal resurfacing prosthesis (Corin, UK) was assessed by measuring the prosthesis-neck ratio on postoperative radiographs. 39 prostheses (35 patients) were measured on plain AP pelvis radiographs taken immediately and mean 2 years post-operatively. Subsequent follow up radiographs were measured up to maximum 7 years follow up, mean 4.75 years.

Results: There was evidence of neck atrophy in 35/39 hips at an average of 2 years post operation, with the overall average neck narrowing from a ratio of 0.86 to 0.81 at 2 years. Average neck ratios were calculated up to 7 years post resurfacing; 25 hips measured at 3 years average ratio of 0.81, 20 at 4 years ratio 0.8, 25 at 5 years ratio 0.8, 9 at 6 years ratio 0.8, 1 at 7 years ratio 0.81.

Discussion: A degree neck resorption occurs with this resurfacing prosthesis by 2 years, however no further resorption appears to occur beyond this, to a maximum follow up of 7 years. This may indicate that early narrowing is more likely to be due to harmless bone adaption then a progressive absorption jeopardising the femoral neck.