Stiffness post-total knee replacement: A proof of principle study investigating the effect of gene expression analysis of markers of fibrosis

BACKGROUND

To establish proof of principle of a link between phenotypic expression and stiffness after TKR.

METHODS

From 100 patients, genetic expression of markers of fibrosis was performed for 15 synovial samples from patients categorised as 'best post-operative range of movement (ROM)' and 15 samples from patients with 'worst ROM'. These markers included Matrix Metalloproteinases (MMPs), A Disintegrin and Metalloproteinases with Thrombospondin (ADAMTS) and Tissue Inhibitors of Matrix Metalloproteinases (TIMPs). Genetic marker data were compared to Oxford Knee Scores (OKS) and Pain Catastrophizing Scores (PCS).

RESULTS

Quantitative markers for gene expression demonstrated more outliers in stiff compared to non-stiff knees, suggesting a greater imbalance in pro- and anti-fibrotic markers in stiff knees. Whilst there was a significant difference in the range of post-operative knee flexion (p = 0.001) and extension (p = 0.001), there was no statistically significant difference between stiff and non-stiff knees in pre-operative or post-operative OKS (p ≥ 0.06). There was no difference in the individual components of the individual PCS score items nor the PCS total scores when stiff and non-stiff knees were compared (p > 0.05).

CONCLUSION

Biological factors, namely gene expression of MMPs, TIMPs and ADAMTS, may contribute towards post-TKR stiffness. This now warrants further investigation to better understand this relationship based on larger, multi-centre, cohorts.

LEVEL OF EVIDENCE

Level 3.

The trochlear isometric point is different in patients with recurrent patellar instability compared to controls: a radiographical study

PURPOSE

The purpose of the study was to investigate the theoretical isometric point based of the curve of the femoral groove and relating it to the origin of the MPFL femoral tunnel on lateral radiograph by comparing a patellar instability cohort with a control cohort.

METHODS

From a Patellar Instability database the radiographs of 40 consecutive patients were analysed to define Schöttle's point, and the arc of the circle of the trochlear groove. A comparison population of 20 radiographs from comparable patients with tibiofemoral joint disorders was used as a control. The distance from Schöttle's point to the most anterior part of the groove (extension) was also compared to the distance to the distal end of the roof of the notch (flexion).

RESULTS

The trochlea was circular in the controls but not the Patellofemoral Instability cohort where trochlear dysplasia is usually present. The difference between the extension and flexion length was a mean of - 2.0 ± 0.5 mm in the controls and + 6.0 ± 0.5 mm in the patellofemoral cohort. In neither cohort did the centre of the circle correspond to Schöttle's point. The extension distance correlated with the boss height.

CONCLUSIONS

The dysplastic trochlea is not circular and the centre of the best matched circle was different to the control trochleae which were circular. The circle centres did not correlate with Schöttle's point for either cohort, and was more proximal in the Patellofemoral Instability cohort.

CLINICAL RELEVANCE

For the MPFL to have equal tension throughout flexion within the groove, the length should not change. In normal knees the MPFL does not behave isometrically. The change in length, as measured from Schöttle's point to the trochlea, was greater for patellofemoral instability patients explaining why an isolated MPFL reconstruction in the presence of severe trochlear dysplasia risks poor outcomes. Level of evidence III.

Surgical fixation methods for tibial plateau fractures

BACKGROUND

Fractures of the tibial plateau, which are intra-articular injuries of the knee joint, are often difficult to treat and have a high complication rate, including early-onset osteoarthritis. Surgical fixation is usually used for more complex tibial plateau fractures. Additionally, bone void fillers are often used to address bone defects caused by the injury. Currently there is no consensus on either the best method of fixation or bone void filler.

OBJECTIVES

To assess the effects (benefits and harms) of different surgical interventions, and the use of bone void fillers, for treating tibial plateau fractures.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (12 September 2014), the Cochrane Central Register of Controlled Trials (2014 Issue 8), MEDLINE (1946 to September Week 1 2014), EMBASE (1974 to 2014 Week 36), trial registries (4 July 2014), conference proceedings and grey literature (4 July 2014).

SELECTION CRITERIA

We included randomised and quasi-randomised controlled clinical trials comparing surgical interventions for treating tibial plateau fractures and the different types of filler for filling bone defects.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, selected studies, extracted data and assessed risk of bias. We calculated risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CIs). Only very limited pooling, using the fixed-effect model, was possible. Our primary outcomes were quality of life measures, patient-reported outcome measures of lower limb function and serious adverse events.

MAIN RESULTS

We included six trials in the review, with a total of 429 adult participants, the majority of whom were male (63%). Three trials evaluated different types of fixation and three analysed different types of bone graft substitutes. All six trials were small and at substantial risk of bias. We judged the quality of most of the available evidence to be very low, meaning that we are very uncertain about these results.One trial compared the use of a circular fixator combined with insertion of percutaneous screws (hybrid fixation) versus standard open reduction and internal fixation (ORIF) in people with open or closed Schatzker types V or VI tibial plateau fractures. Results (66 participants) for quality of life scores using the 36-item Short Form Health Survey (SF-36)), Hospital for Special Surgery (HSS) scores and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scores tended to favour hybrid fixation, but a benefit of ORIF could not be ruled out. Participants in the hybrid fixation group had a lower risk for an unplanned reoperation (351 per 1000 people compared with 450 in the ORIF group; 95% CI 197 fewer to 144 more) and were more likely to have returned to their pre-injury activity level (303 per 1000 people, compared with 121 in the ORIF group; 95% CI 15 fewer to 748 more). Results of the two groups were comparable for the WOMAC pain subscale and stiffness scores, but mean knee range of motion values were higher in the hybrid group.Another trial compared the use of a minimally invasive plate (LISS system) versus double-plating ORIF in 84 people who had open or closed bicondylar tibial plateau fractures. Nearly twice as many participants (22 versus 12) in the ORIF group had a bone graft. Quality of life, pain, knee range of motion and return to pre-injury activity were not reported. The trial provided no evidence of differences in HSS knee scores, complications or reoperation entailing implant removal or revision fixation. A quasi-randomised trial comparing arthroscopically-assisted percutaneous reduction and internal fixation versus standard ORIF reported results at 14 months in 58 people with closed Schatzker types II or III tibial plateau fracture. Quality of life, pain and return to pre-injury activity were not reported. There was very low quality evidence of higher HSS knee scores and higher knee range of motion values in the arthroscopically assisted group. No reoperations were reported.Three trials compared different types of bone substitute versus autologous bone graft (autograft) for managing bone defects. Quality of life, pain and return to pre-injury activity were not reported. Only one trial (25 participants) reported on lower limb function, finding good or excellent results in both groups for walking, climbing stairs, squatting and jumping at 12 months. The incidences of individual complications were similar between groups in all three trials. One trial found no cases of inflammatory response in the 20 participants receiving bone substitute, and two found no complications associated with the donor site in the autograft group (58 participants). However, all 38 participants in the autologous iliac bone graft group of one trial reported prolonged pain from the harvest site. Two trials reported similar range of motion results in the two groups, whereas the third trial favoured the bone substitute group.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to ascertain the best method of fixation or the best method of addressing bone defects during surgery. However, the evidence does not contradict approaches aiming to limit soft-tissue dissection and damage or to avoid autograft donor site complications through using bone substitutes. Further well-designed, larger randomised trials are warranted.

A preference-based single-item measure of quality of life following medial opening wedge high tibial osteotomy: large improvements similar to arthroplasty

BACKGROUND

Improvements in generic and disease specific scores have been reported with medial opening wedge high tibial osteotomy (MOW HTO). However, meaningful comparisons between competing surgical interventions have been hampered by the lack of a preference based single index of health related quality of life (HRQoL). The primary aim of this study was to derive and report a single index measure of HRQoL for patients undergoing MOW HTO, preoperatively and at 12 and 24 postoperatively. Secondary aims were to evaluate changes in various additional measures of quality of life at these time points.

METHODS

The impact of MOW HTO was evaluated using generic and disease specific instruments. One hundred thirty eight patients completed the Medical Outcomes Study short form health survey (SF-12) and Knee Osteoarthritis Outcomes Score (KOOS) before, 12 and 24 months after surgery. A preference-based single index measure of HRQoL was calculated and changes were evaluated.

RESULTS

The mean change in the HRQoL suggested large, clinically significant improvements from 0.69 preoperatively to 0.82 (p<0.001) and 0.8 at 12 and 24 months postoperatively respectively. All dimensions of the SF-12, except role mental health, and all dimensions of the KOOS also demonstrated statistically significant improvements between pre and postoperative measurements.

CONCLUSIONS

The preoperative HRQoL of young patients with mechanical varus alignment and medial compartment knee osteoarthritis is similar to older patients with knee osteoarthritis. Medial opening wedge high tibial osteomoty results in significant improvements in HRQoL, the magnitude of which is comparable to other surgical interventions for knee osteoarthristis.

The effect of the addition of hydroxyapatite graft substitutes upon the hoop strain and subsequent subsidence of a femoral model during impaction bone grafting

Impaction bone grafting using morcellised allograft can successfully restore bone stock in revision surgery. However, concerns exist regarding supply of bone and transmission of infection. Bone-graft extenders, such as tricalcium phosphate (TCP) and hydroxyapatite (HA), are used to minimise the use of donor bone. However, concerns exist around a reported increased risk of femoral fracture during impaction bone grafting with a 1:1 mixture of TCP/HA and morcellised bone graft (MBG) during impaction grafting in human cadaveric femora. Using a sawbones model, it was evaluated whether there was increased femoral cortical strain with a HA:MBG mixture during impaction grafting compared to MBG impacted at the same and a greater force. Subsequently the subsidence behaviour of the different graft mixes was compared by using a loaded femoral stem in an endurance test. It was demonstrated that the femora with the MBG:HA graft had greater cortical hoop stresses but improved subsidence behaviour compared to a graft composed of pure MBG impacted at the same force.

A survey of post-intake orthopaedic trauma meetings in England

INTRODUCTION

The structure of trauma meetings has been noted to vary considerably throughout our region. The aim of this study was to assess current practice of trauma meetings on a national level and to propose a structure on the basis of the survey.

MATERIALS AND METHODS

A telephone survey of 120 hospitals in England was performed with a 100% response rate. The on-call duty orthopaedic surgeon at each hospital was contacted and questioned regarding trauma meetings held at that hospital. Details obtained included the frequency of meetings, the presence of medical staff and staff from other disciplines, review of radiographs and educational value.

RESULTS

In total, 107 (89.2%) hospitals conducted regular trauma meetings with a mean duration of 36 min (range, 15-120 min). Teaching of junior medical staff occurred at 89 (83.2%) meetings. Postoperative radiographs were reviewed at 80 (74.8%) hospitals. A radiologist attended in 5 (4.7%) of meetings. The median number of consultants present was 3 (range, 1-10). Other attendees included trauma co-ordinators (34.6%), physiotherapists (30.8%), theatre staff (23.4%), nursing staff (20.6%) and anaesthetists (15.9%).

CONCLUSIONS

Trauma meetings assist with the organisation of trauma lists, the review of results and have a valuable educational component. However, in busier orthopaedic units, additional meetings for teaching purposes may be necessary as an adjunct to routine daily trauma meetings.

Ocular contamination during lesional surgery—a hazard for the plastic surgeon

Protective glasses reduce the risk of transconjunctival virus transmission although this has never been characterised for local anaesthetic skin lesion surgery. This study investigated the use of, and need for, protective eyewear during Plastic Surgery and the surgeons' attitude to risk.

MATERIALS AND METHODS

Study 1. A multi-center questionnaire recorded the attitudes of Plastic Surgeons' regarding google use and ocular viral transmission. Study 2. A single surgeon performed local anaesthetic skin lesion surgery over 8 months whilst wearing clean goggles. After each procedure the goggles were inspected for macroscopic splashes ans a record made of whether the operator had been aware of the splash occurrence.

RESULTS

Study 1. There were 36 respondents to the questionnaire (response rate of 84%). All grades recognised the risk of conjunctival contamination but most respondents did not wear goggles. Respondents changed their behavior, however, in 'high risk' cases. Study 2. 143 procedures resulted in 42 splashes. The surgeon was only aware of the splash in 6 cases.

CONCLUSION

Despite widespread recognition of the importance of eye protection, goggle use is still infrequent. Our study stresses the frequency of potential splashes to the eye and need for routine use of goggles to prevent viral transmission.

The delayed diagnosis of radial head fractures

Radial head fractures are a common orthopaedic injury presenting to Emergency Departments. Most are diagnosed radiographically, either with a visible fracture or by the presence of abnormal fat pads. We present two cases of delayed radiological diagnosis of radial head fractures despite a high index of clinical suspicion of a fracture at initial consultation.

Fine needle aspiration cytology prior to breast ultrasonography does not alter ultrasound diagnostic accuracy or patient management

INTRODUCTION

Fine needle aspiration cytology (FNAC) prior to serial sonographic (USS) examination of the breast is said to impede accurate diagnosis. This study aimed to test the effect of performing FNAC prior to USS in a one-stop symptomatic breast clinic.

METHODS

All patients (n=368) attending a one-stop clinic over a 1-year period were stochastically allocated to imaging prior to (Group 1) or after (Group 2) clinical examination and FNAC. Additional procedures required for diagnosis (open or core biopsies), false negative USS grade and final outcome were recorded. Statistical analysis was performed using the Fisher's exact test.

RESULTS

There was no statistical difference between the two groups.

CONCLUSION

In the clinical setting of a one-stop visit, FNAC prior to breast USS does not alter ultrasound diagnostic accuracy or patient management.

Volume and differentiation of striatal grafts in rats: relationship to the number of cells implanted

A growing body of evidence suggests that graft-mediated functional recovery in animal models of Huntington's disease is influenced by the morphology of the striatal grafts. Various parameters, including embryonic dissection, tissue preparation, and surgical delivery into the brain, have been investigated with the aim of increasing the proportion of the grafts comprising striatum-like tissue. While growing evidence suggests that implants derived from the selective dissection of the lateral ganglionic eminence (LGE) contain more striatal tissue, the relationship between the quantity of LGE tissue implanted and the striatum-like proportion of the resultant grafts has not been formally investigated. In this study the volume of striatum-like tissue within the grafts did not increase in a linear manner with increasing numbers of cells implanted. The proportion of the grafts that comprised the striatum-like patch compartment or P-zone remained constant after an initial rapid increase as the number of LGE cells implanted was increased. These results have important practical implications in determining the optimum number of LGE cells to implant and hence in the design of any surgical protocol for the clinical application of this technique.