In light of recent regulatory initiatives, medical devices now require additional clinical evidence to prove their safety and efficacy. At the same time, patients' own assessment of their devices' function and performance has gained in importance. The collection of these data allows for a more comprehensive picture of clinical outcomes and complications following total knee arthroplasty (TKA).

These trends have led researchers to search for new methods of acquiring, interpreting and disseminating patient-reported outcome measurements (PROMs). The current study assesses the feasibility of a digital platform for collecting PROMs that was recently adapted for TKA patients. It sought to determine patient engagement, survey completion rates, and satisfaction with this platform.

Eighty-two patients (mean age, 63.7 years, 59% females) scheduled for TKA were enrolled from one US and six UK sites between January 12, 2018 and April 30, 2018. Patients were supplied with a mobile application (app) that collects a variety of PROMs, including four domains based on the Patient-Reported Outcome Information System (PROMIS™): physical function, depression, pain interference and pain behavior. The platform electronically administers questionnaires using computer-adaptive tests (CATs), which reduce the burden on patients by tailoring follow-up questions to account for their previous answers. Satisfaction with the app was assessed in subset of patients who evaluated its ease-of-use (n=45), likelihood that they would recommend it to family/friends (n=35), and whether they successfully used the information it provided during their recovery (n=31). These scores were taken on a 1 to 10 (worst to best) scale.

Patients demonstrated regular engagement with the platform, with 73% using the app at least once a week. Weekly engagement remained high throughout the seven-week post-operative period (Figure 1). There was a 69% completion rate of all PROMIS™ CAT surveys during the study. The four PROMIS™ CAT domains had similar survey completion rates (Figure 2). The subset of patients queried regarding their satisfaction with the app gave it favorable mean scores for ease-of-use (8.8), likelihood to recommend to a family member or friend (8.1), and their success at using its information to improve their recovery (7.4).

Initial results support this digital platform's potential for successfully and efficiently collecting large volumes of PROMs. Patients reported high levels of engagement and satisfaction.

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Introduction

Haemodynamically compromised patients with biomechanically unstable pelvic fractures need reduction of the pelvic volume to effect tamponade of bleeding bone and vessels. Knee binding, to help achieve this, is advocated in standard Advanced Trauma and Life Support teaching but is rarely used. There are no reports in the literature as to the benefits derived from this simple manoeuvre. The aim of this study was to investigate whether there was an effect on symphysis pubis closure by binding the knees together and to quantify this.

Introduction

The proximity of the superior tibiofibular articulation to neurovascular structures makes the management of extraosseous tumours of the proximal fibula challenging in bone tumour surgery. The aim of study is to establish whether the recurrence rates are higher in this anatomical area compared to data that already exists in publication for bone tumours throughout the appendicular skeleton.

Introduction: Preliminary studies suggest that prolonged retraction of the paraspinal muscle during spinal surgery may produce ischaemic damage. We describe the continuous measurement of intramuscular pressures (IMP) during decompressive lumbar laminectomy and the relationship to back pain and disability.

Methods: In this prospective interventional study, 28 patients undergoing surgery for lumbar canal stenosis were recruited. Back pain and function were assessed using the Visual Analogue Score (VAS), Oswestry Disability Index (ODI) and Short Form 36 (SF36) health survey. During surgery, IMP was continuously recorded from the multifidus muscle using a pressure transducer. The intramuscular perfusion pressure (IPP) was derived as the difference between the patient’s mean arterial pressure (MAP) and IMP (IPP = MAP − IMP). The data was analysed using repeated measures ANOVA (SPSS package).

Results: The mean age was 60.4 ± 3 years and the mean duration of symptoms of 31.0 ± 6 months. The predominant symptoms were neurogenic claudication (14) and/or sciatica (13). Patients underwent 1 (N=3), 2 (N=20) or 3 (N=5) level laminectomies. The muscle retractors used were Norfolk and Norwich (N=16) and McCullock (N=12). The mean duration of deep muscle retraction was 68.5 ± 9 mins (range 19–240). On application of deep muscle retraction, there was a rapid and sustained increase in IMP (F=26.8; p< 0.001; repeated measures ANOVA), and overall the calculated mean IPP approached 0 mmHg or less during this period (F=36.8; p< 0.001). On release of deep muscle retraction there was a rapid decrease in IMP to pre-operative levels. The IPP was greater with Norfolk and Norwich than McCullock retractors (F=12.2; p< 0.001). Compared to pre-operative values, there was a decrease in ODI (F=18.6; p< 0.001) and VAS for back pain (F=9.9; p< 0.001) at discharge, 4–6 weeks and 6 months, post-operatively. Compared to pre-operative values, there was a decrease in SF36 scores at 6 months (F=26.7; p< 0.001). Total duration of muscle retraction over 60 mins was associated with higher VAS scores for back pain at 4–6 weeks and 6 months postoperatively (F=3.7; p< 0.01). There was no relationship between IPP and post-operative ODI or VAS for back pain.

Conclusions: This study demonstrates a simple technique for the continuous monitoring of IMP during spinal surgery, from which the IPP can be derived. Comparison of two muscle retractors has shown that the McCullock retractor generates a higher IMP than Norfolk and Norwich retractor. Decompressive lumbar laminectomy improves the VAS for back pain and ODI and SF36 outcome scores in these patients. The results show that duration of muscle retraction, rather than extent of the pressure generated by the retractor, is related to postoperative back pain.