By: 11 January 2019
Showcase of abstracts at Orthopaedic Knee Conference

We take a look of a selection of the abstracts that were presented at this year’s conference in Leeds

Outcomes of tension band wiring patellar fractures: A high complication rate

O.O’Malley, C. Hing, St George’s Hospital; A. Haiduc, St George’s University

Background

Patellar fractures account for 1 per cent of all fractures. There are only 15 studies published in the last five years (mean sample size 45) that outline the outcome of patellar fixation. Our goal was to review current surgical treatment strategies and compare the outcomes of those in our institution.

Methods

We performed a retrospective cohort study comparing the incidence of complications indifferent methods of patellar fracture fixation in patients treated from October 2012 to October 2017. Demographics, mechanism of injury, fracture pattern, concomitant injury, fixation method and complications (decreased ROM,infection and removal of hardware) were recorded.

Results

Seventy-three patients were identified with a cohort of 58 (34 male, 24 female) available for final analysis. The mean age was 43 years with the commonest mechanisms of injury being a fall (58 per cent) and road traffic accident (33 per cent). 50 per cent of fractures were comminuted, 50 per cent transverse and the majority of fractures were closed (81 per cent). 14 patients had concomitant ipsilateral injuries of the lower limb. Fractures were fixed using the following methods either individually or in combination: tension band wiring (TBW), cerclage wire, sutures, screws and plates. 

Forty-two patients had fixation involving TBW, of these, 42 per cent had a reduced range of motion(ROM), 12 per cent developed an infection and 60 per cent required removal of hardware. 18 patients had fixation involving cerclage wire, of these, 27 percent had reduced ROM, 16 per cent developed an infection and 55 per cent required removal of hardware (90 per cent of these involved fixation with an additional TBW). Six patients were treated with sutures, of these, 17 per cent had a reduced ROM and 17 per cent developed an infection. Six patients had fixation involving screws, of these 33 per cent had reduced ROM, 17 per cent developed an infection and 33% required removal of hardware (all involving dual fixation with TBW).

Conclusions

This is the largest series studied when comparing the outcomes of multiple (>2) fixation techniques. The TBW technique is by far the commonest fixation technique for patellar fractures. This study shows that it produces a high level of complications and statistically significantly (p< 0.05) more episodes of hardware removal. Is it time to start thinking about a new gold standard?

Accelerated recovery for unicompartmental knee replacements carried out at Stobhill Hospital, Glasgow

R Steedman, A Maclean

Background

With the increasing stress on the National Health Service, the audit was carried out to investigate whether the length of stay for unilateral knee replacement patients can be reduced. This would allow for fewer cancellations, potentially fewer hospital-acquired infections and would balance inpatient and outpatient flow.The protocol may help discharge rates increase if patient satisfaction following the procedure is high. It is proposed that those patients who had a shorter stay in hospital will have fewer post-operative complications and be just as satisfied overall as those patients who had a longer stay.

Methods

The study included 13patients from Stobhill hospital, that is a short stay facility with limited beds and generally houses day surgical patients, who were compared to a control group of patients from Glasgow Royal Infirmary, which is a much bigger city hospital. Each patient was phoned and a standardised questionnaire conducted to gauge patient satisfaction and any improvements that they would have liked.Anaesthetic data was also collated and Trakcare online portal used to obtain information about pain medications prescribed, physiotherapy data, radiology data and the patients overall length of stay.

Results

Most patients had a spinal and an adjuvant adductor canal block. Patients at Stobhill were generally discharged after 1.2 nights on average in comparison to Glasgow RoyalInfirmary, where patients stayed for an average of 3.8 nights. At Stobhill, patients were seen by physiotherapy mostly on the day of their operation,whereas at Glasgow Royal it was the morning after. All 26 patients had a post-operative X-ray the following morning. Stobhill patients were prescribed fewer pain medications than patients at Glasgow Royal and the strength of these pain medications tended to be higher on the pain ladder than patients at Stobhill. Pain control satisfaction at hospital across both sites was high however issues arose when discharged home. Readiness to leave the hospital was overall lower at Stobhill, meaning patients felt they could have stayed longer.Glasgow Royal patients also experienced more post-operative complications/inconveniences. Satisfaction overall was similar across both study sites.

Conclusion

Patient satisfaction for an accelerated stay and recovery in Stobhill was mixed similar to Glasgow patients, so there remains improvements to be made in future for this procedure. Plans that would be of benefit could be a larger patient education programme, better pain control at home and a consistent pain medication protocol across all sites for the unilateral knee replacement.

SPARC Anaemia – Incidence and management of preoperative anaemia in elective orthopaedics in Wessex

Presenting author: Mr Luis Martul, Queen Alexandra Hospital, Portsmouth

Lead author: Dr I Delroy-Buelles

Lead Investigators: Dr R. Sands, Dr J. Goddard, Mr L. Martul, Dr A-M. Kent, Dr D. Lipner and Dr K. Wainwright

Background

Pre-operative anaemia has been associated with increased morbidity, mortality and blood transfusion rates. Guidelines have been published recommending identification and management of preoperative anaemia, particularly the NATA guidelines for elective orthopaedics. We sought to investigate the current incidence and management of pre-operative anaemia, and transfusion rates in an elective orthopaedic population in the Wessex region.

Methods

Lead investigators were appointed in hospitals across the Wessex and in each the most recent 50 elective primary THRs and TKRs were identified. Data on their preoperative anaemia status and any subsequent investigations and transfusions were collected. Analysis was undertaken using descriptive terminology, and for non-standard data median with 25-75 per cent interquartile ranges were calculated. There were no cases of missing data.

Results

A total of 237 THR and 242 TKR were examined. In the THR group 14 per cent of patients were anaemic preoperatively, further investigation of the anaemia was undertaken in 38 per cent, though only 6 per cent received any treatment for their anaemia. While the overall transfusion rate in this group at 2 per cent was low, 60 per cent of these were anaemic preoperatively.

In the TKR group 13 percent of patients were anaemic preoperatively, with only 42 per cent having any further investigation of their anaemia and only 23 per cent receiving any treatment for their anaemia. Again, transfusion rates in the whole group were low at 3 per cent, though almost 60 per cent were anaemic before surgery.

Conclusion

Despite a 13 per cent prevalence of anaemia, only 40 per cent of patients found to be anaemic had further investigations, and only 6 per cent of THRs and 23 per cent of TKRs had any preoperative treatment. The reasons for this may include awareness of the definition of and morbidity and mortality associated with preoperative anaemia and limited pathways of treating anaemia when identified as a problem.Transfusion rates in both groups were reassuringly low, but 60 per cent of the patients who received blood transfusions were anaemic preoperatively. Treatment of these patients may have avoided blood transfusion in these cases, and would be supported by current best practice evidence in this area. Overall, this audit has shown areas for improvement in practice in the identification and optimisation of patients with preoperative anaemia in an elective orthopaedic population in Wessex. The median time of around 30 days from preoperative assessment and blood tests to operation date would indicate there is time for optimisation.

We aim to raise awareness in our trusts and lead to pathway developments for improving optimisation in this group.

Knee dislocations after low velocity trauma – are they becoming more common?

Mark McMullan, Trauma & Orthopaedic Registrar, Northern Deanery – James Cook Hospital

Introduction

The purpose of this study was to evaluate the incidence of native knee dislocations presenting to our hospital, their initial management and identify rates of low-velocity injuries and if there was a link to an increased body mass index (BMI).

Methods

A retrospective study of a 24-month period from 2016-17 was performed at a level-one trauma centre, identifying six patients who sustained a knee dislocation.

Results

Four of the six patients, all with a BMI greater than 25, sustained a low velocity trauma. Five had a confirmed diagnosis of a dislocation on MRI and four went on to have definitive surgery after a median time of 13 days. All patients clinically diagnosed had initial stabilisation in A&E, yet only three underwent CT angiography to investigate the occurrence of a vascular injury. No patient was diagnosed with a vascular injury.

Discussion

On the basis of the population served by our trauma centre, the annual incidence of knee dislocation is about 0.5 per million. Two-thirds of these injuries were associated with a low energy trauma. As the prevalence of obesity increases,the diagnosis of knee dislocation should be suspected in patients sustaining low velocity trauma and clinicians should have a low threshold for obtaining further cross-sectional imaging.

Common peroneal neuropathy caused by the fabella: Case report and literature review

Yi-Hsuan Lee, Department of Orthopedics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, NewTaipei, Taiwan; Chung-Ting Wu, Department of Orthopedic Surgery, Cathay GeneralHospital, Taipei, Taiwan; In-Ho Chen, Department of Orthopedics, Hualien TzuChi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan

Objective

Common peroneal nerve palsy is the most common entrapment neuropathy in the lower extremities and because of the anatomical characteristics, various etiologies have been identified. In this report, we present a rare case of common peroneal palsy secondary to compression by the fabella, and review the literature for its anatomical characteristics, clinical features and management.

Materials and methods

A 79-year-old woman who presented with progressive numbness and a tingling sensation in the lateral calf and dorsum of the foot. Contrast enhanced MRI showed perineural edema, and a 1.5cm fabella bone just underneath peroneal nerve (Fig.1). NCV and EMG studies revealed complete motor and sensory blockage of the peroneal nerve.Surgical exploration was performed after failed conservative treatment (Fig.2), peroneal nerve neurolysis and fabella bone excision was performed.

Figure 1: Peroneal nerve compressed by fabella bone under T2 MRI. White arrow: fabella bone, red arrow: perineural edema of peroneal nerve.
Figure 2: Peroneal nerve became swelling and petechial change, underneath is fabella bone.

Results

Alleviation of numbness and tingling sensation in calf and foot was soon noted at 12 hours post-operatively. Followed with subsequent rehabilitation programme, fully recovery of both sensory and motor deficit was noted in nine months.

Conclusion

We present a case of compressive peroneal neuropathy caused by the fabella, which is rare, with only nine previously published articles found. In our experience, we suggest prompt surgical exploration and release/remove the source of compression once the diagnosis has been confirmed. Conservative treatment is with little value in treating compressive neuropathy. EMG, NCV andMRI are crucial investigations for differential diagnosis and preoperative targeting. Prompt surgical management provided favourable outcomes and early recovery.