Introduction

Numerous musculoskeletal and systemic conditions may affect the hips of paediatric patients. While the large majority of patients go on to achieve positive outcomes, a small number will progress to end stage arthropathy with significant functional impairment. Management options have been significantly limited for this population. An adolescent hip arthroplasty program was developed with the aim to improve symptoms and quality of life for patients with pain and disability refractory to joint preserving management strategies.

Lower-extremity orthopaedic procedures may be performed under either regional or general anaesthesia, or a combination of both techniques. There is a growing body of evidence supporting the benefits of regional anaesthesia, with meta-analyses of randomised controlled trials and registry data suggesting decreases in deep surgical site infections, thromboembolic events, cardiopulmonary complications and length of stay associated with use of regional anaesthesia. In patients undergoing foot and ankle surgery specifically, there is evidence demonstrating decreased post-operative pain, nausea, vomiting, opioid use and unplanned hospital admission. This supports an increased role for the use in regional anaesthesia in patients undergoing foot and ankle surgery. However, the type of anaesthetic used is dependent on surgeon, patient, anaesthesiologist and institutional factors. The purpose of this study is to investigate pre-operative factors that predict the type of anaesthetic used in patients undergoing foot and ankle surgery.

Data was collected prospectively on 888 patients undergoing foot or ankle surgery at a single institution. The primary method of anaesthesia for each procedure was recorded. Ten additional variables were recorded and analysed: age, BMI, gender, diabetes, ASA status, procedure length, procedure start time, elective vs. trauma procedure, primary vs. revision procedure and preoperative anticoagulation. Logistic regression modelling was performed to identify factors that independently predict the type of anaesthetic used.

General anaesthetic was employed in 280 patients (32%), and regional anaesthesia was the primary anaesthetic type used in 608 (68%). Logistic regression modelling demonstrated that factors that independently predict use of general anaesthetic include younger age (p<0.0001; Odds Ratio 0.97/year), male sex (0.0033; 1.618), procedure start time (0.0319; 1.066/hour) and length of procedure (<0.0001; 1.520/hour). Patients who underwent general anaesthetic had a mean length of procedure of 108 +/− 77 minutes, whereas patients provided with regional anaesthesia had a mean length of procedure 83 +/− 64 minutes.

With increasing evidence supporting the benefits of regional anaesthesia in patients undergoing lower extremity surgery, it is important to identify modifiable factors that contribute to patients receiving alternative treatments. Since later procedure start time was identified as an independent predictor of general anaesthetic use, there may be a role for identifying patients at increased risk of complications associated with general anaesthesia and scheduling earlier start times. Furthermore, while it is logical that extended length of procedure may be a contraindication to regional anaesthesia, the mean procedure time of 108 minutes in the general anaesthesia group indicates that many of these patients should still be considered candidates for regional anaesthesia.

In the current health care climate, there is an increasing focus on cost savings and resource management. As such, there is an emphasis on decreasing length of stay and performing surgery on an outpatient basis. Consequently, some patients will have unanticipated intra-operative or post-operative adverse events that will necessitate an unplanned post-operative hospital admission or a readmission after discharge. These unplanned admissions or readmissions represent an increased burden on health care systems and can cause cancellation of other scheduled procedures. The purpose of this study is to investigate whether pre-operative patient risk factors or intra-operative events could predict unplanned admission or readmission following discharge in patients undergoing either elective or emergency foot and ankle surgery.

Data was prospectively collected on a total of 889 patients. The patients were divided into two groups: patients without readmissions (N=791) and patients who had an unplanned admission or readmission (N=98). We also collected and analysed the following variables: age, gender, BMI, diabetes, ASA class, surgery start time, length of surgery, regional vs. general anesthetic, elective vs. trauma surgery and type of procedure. Logistic regression models were used to identify risk factors that could independently predict unplanned admissions or readmissions to hospital following foot and ankle surgery.

Factors that could be used to independently predict readmission were length of surgery (p 0.0154, Odds Ratio 1.004) and trauma surgery (0.0167; 1.978). For every 1-hour increase in length of surgery, the odds of unplanned admission/readmission increase by 1.27 times. The odds of patients undergoing surgery for acute traumatic injuries getting readmitted are 1.978 times higher than for elective surgery patients.

In conclusion, our study showed that pre-operative patient risk factors including BMI, diabetes, and ASA status were unable to predict whether patients would have an unplanned admission or readmission. The two factors that were able to predict whether patients would have an unplanned admission or readmission were length of the procedure and trauma surgery – both of which are not readily modifiable. Our results showed that in spite of institutional measures to ensure timely discharge, only 11% of patients required an unplanned admission or readmission.