Postoperative surgical site infection in patients treated with lumbosacral fusion has been believed to be caused by perioperative contamination (Perioperative Inside-Out infections) in patients with comorbidities. With the proximity of these incisions to the perianal region and limited patient mobility in the early post-operative period, local contamination from gastrointestinal and/or urogenital flora (Postoperative Outside-In infections) should be considered as a major source of complication.

A single center, retrospective review of adult patients treated with open posterior lumbosacral fusions between January 2014 and January 2021. We aimed to identify common factors in patients experiencing deep postoperative infections. Oncological, minimally invasive, primary infection, and index procedures carried out at other institutions were excluded.

We identified 489 eligible patients, 20 of which required debridement deep to the fascia (4.1%). Mean age (62.9 vs 60.8), operative time (420 vs 390 minutes), estimated blood loss (1772 vs 1790 mL) and median levels fused (8.5 vs 9) were similar between the infected and non-infected groups. There was a higher percentage of deformity patients (75% vs 29%) and increased BMI (32.7 vs 28.4) in the infected group. The mean time from primary procedure to debridement was 40.8 days. Four patients showed no growth on culture. Three showed Staphylococcus species (Perioperative Inside-Out infections) requiring debridement at a mean of 100.3 days (95%CI 0- 225 days). Thirteen patients showed infection with intestinal or urogenital pathogens (Postoperative Outside-In infections) requiring debridement at a mean of 20.0 days (95%CI 9-31 days). Postoperative Outside-In infections led to debridement 80.3 days earlier than Perioperative Inside-Out infections (p= 0.007).

In this series, 65% of deep infections were due to early local contamination by gastrointestinal and/or urogenital tracts pathogens. These infections were debrided significantly earlier than the Staphylococcus species infections. Due to the proximity of the incisions to the perianal region, there should be increased focus on post-operative local wound management to ensure these pathogens are away from the wound during the critical stages of wound healing.

Single level discectomy (SLD) is one of the most commonly performed spinal surgery procedures. Two key drivers of their cost-of-care are duration of surgery (DOS) and postoperative length of stay (LOS). Therefore, the ability to preoperatively predict SLD DOS and LOS has substantial implications for both hospital and healthcare system finances, scheduling and resource allocation. As such, the goal of this study was to predict DOS and LOS for SLD using machine learning models (MLMs) constructed on preoperative factors using a large North American database.

The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for SLD procedures from 2014-2019. The dataset was split in a 60/20/20 ratio of training/validation/testing based on year. Various MLMs (traditional regression models, tree-based models, and multilayer perceptron neural networks) were used and evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure real world applicability, the results of the models were compared to a mean regressor model.

A total of 11,525 patients were included in this study. During validation, the neural network model (NNM) had the best MSEs for DOS (0.99) and LOS (0.67). During testing, the NNM had the best MSEs for DOS (0.89) and LOS (0.65). The NNM yielded the best 30-minute buffer accuracy for DOS (70.9%) and ≤120 min, >120 min classification accuracy (86.8%). The NNM had the best 1-day buffer accuracy for LOS (84.5%) and ≤2 days, >2 days classification accuracy (94.6%). All models were more accurate than the mean regressors for both DOS and LOS predictions.

We successfully demonstrated that MLMs can be used to accurately predict the DOS and LOS of SLD based on preoperative factors. This big-data application has significant practical implications with respect to surgical scheduling and inpatient bedflow, as well as major implications for both private and publicly funded healthcare systems. Incorporating this artificial intelligence technique in real-time hospital operations would be enhanced by including institution-specific operational factors such as surgical team and operating room workflow.

Abstract

Aims

The aim of this study was to assess the feasibility of conducting a full-scale, appropriately powered, randomized controlled trial (RCT) comparing internal fracture fixation and distal femoral replacement (DFR) for distal femoral fractures in older patients.

Background

The National Confidential Enquiry into Perioperative Deaths recommends that high-dependency (HDU) or intensive care unit (ICU) care is available following arthroplasty. In hospitals without dedicated post-operative care units, patients can be transferred to wards more rapidly, which is associated with adverse surgical outcome, increased morbidity & mortality and unplanned HDU/ICU admission. Pre-operative assessment clinics (POAC) have been demonstrated to reduce these adverse outcomes. We present an evaluation of HDU/ICU admissions and a micro-cost effectiveness evaluation of POAC and planned HDU/ICU admission in hip/knee arthroplasty.

Introduction

Wolff's Law proposes that trabecular bone adapts in response to mechanical loading and that trabeculae align with the trajectory of predominant loads. The current study is aimed to investigate trabecular orientation in the tibia in patients with osteoarthritis of the knee. Consistent with Wolff's Law, it was hypothesised that orientation would reflect the mechanical loading of the joint and hence that there would be a correlation between the trabecular orientation and the mechanical axis of the lower limb.

Blockade of the suprascapular nerve (SSN) with local anaesthetic is used frequently in shoulder surgery and for chronic shoulder pain. Anatomical landmarks may be used to locate the nerve prior to infiltration with local anaesthetic, but ultrasound is becoming a popular to locate the nerve.

Twelve cadaveric shoulders from 6 specimens were injected with dye using the landmark and ultrasound technique. The shoulders were scanned with computed tomography, and then dissected to ascertain the accuracy of each technique.

Using CT scan results, we found the ultrasound group to be more accurate in placing the anaesthetic needle close to the suprascapular notch, and therefore nerve, and this was significant (p = 0.0009). When analysing the ink data, although we did not observe a significant difference in amount of nerve covered by ink, we did note a correlation, and, given this study group is small, that may be considered a statistical trend.

This study, which is one of the largest cadaveric studies investigating landmark and ultrasound guided block of the suprascapular nerve and we believe the first to use CT, demonstrates that ultrasound guided block is significantly more accurate than the landmark technique, and would therefore recommend that ultrasound guidance be used when blocking the suprascapular nerve, given its higher accuracy and lower complication rate.

Last minute cancellations of operations are a major waste of NHS resources. This study identifies the number of late cancellations at our elective orthopaedic centre, the reasons for them, the costs involved, and whether they are avoidable.

Last minute cancellations of operations in a 7-month period from January to July 2009 were examined.

172 cases out of 3330 scheduled operations were cancelled at the last minute (5.2%). Significantly more cancellations occurred during the winter months due to seasonal illness.

The commonest causes for cancellation in descending order of frequency were patient unfit/unwell (n=76, 44.2%), lack of theatre time (n=32, 18.6%), patient self cancelled/DNA (n=20, 11.6%), staff unavailable or sick (n=9, 5.2%), theatre or equipment problem (n=8, 4.7%), operation no longer required (n=8, 4.7%), administrative error (n=7, 4.1%) or no bed available (n=5, 2.9%). In 7 out of the 172 cancelled cases (4.1%) no cause was identified. 59.7% of the cases were potentially avoidable.

3.2% of Patients seen in the specialist pre-operative anaesthetic clinic (POAC) were cancelled at the last minute for being unfit or unwell, compared to 2.2% seen in the routine nurse led clinic. Last minute cancellations cost the hospital over £700,000 in 7 months.

Purpose: Factors influencing patient willingness to undergo elective surgery are poorly understood.

Method: We prospectively evaluated patient concerns prior to surgical consultation for elective spinal, hip, knee, shoulder/elbow (S/E), or foot/ankle (F/A) conditions. Patients were surveyed for demographic data, SF 36 quality of life (QOL) scores and asked to report their greatest concern about considering surgery for their condition, as well as their willingness to undergo surgery if it was offered to them by their treating surgeon.

Results: In our prospective cohort of 743 patients, 364 (51%) were male and 293 (39 %) were evaluated for a spine condition, 74 (10 %) hip, 192 (26 %) knee, 69 (9 %) S/E, and 115 (16 %) F/A. Mean QOL scores were similar for patients across specialities. The top three greatest concerns for undergoing elective musculoskeletal surgery were potential complications (20%), effectiveness (15%) and recovery time (15%) of surgery. When categorized by specialty, concern of surgical complications was the most prevalent in spine (23%) and F/A patients (30%). However, patients were most commonly unsure of risks associated with their respective subspecialty surgery (spine – 56%; hip – 53%; knee – 44%; S/E – 48% and F/A – 33%). The majority of hip patients (89%) perceived a high success rate for hip surgery, while 65% of spine patients where unsure of the success of spine surgery. Patient willingness to undergo surgery was greatest for hip (84%), knee (78%), and S/E (82%) surgery and least for spine (68%) and F/A surgery (74%).

Conclusion: Although patient willingness to consider surgery is clearly a multifactorial decision, patient perception of surgical risk or success prior to surgical consultation are significant factors.

Background and purpose of study: Intervertebral disc height loss is associated with decreased spinal stability and increased loading on spinal structures, which may be a source of back pain. In the past, total stature change, measured using stadiometry, has often been used as an indication of disc height loss and as an index of the load on the spine. The aim of this study was to use an upright MRI scanner to investigate the changes in lumbar disc dimensions following a short-term loading protocol. It was hypothesized that there would be a linear relationship between the loss in total lumbar disc height and a measure of stature change obtained from a stadiometer.

Method and Results: Thirteen participants with no history of low back pain were recruited. Stadiometer measurements and MRI images of the lumbar spine were obtained both before and after 15-minutes of walking wearing a weighted vest. Contrary to the original hypothesis, no correlation (r = 0.32) was found between total disc height loss measured via MRI and via stadiometry. However a correlation (r = 0.54) was found between stature loss measured on the stadiometer and the decrease in posterior spine length.

Conclusion: The results suggest that stadiometry should not be used to quantify the change in individual disc height or individual disc compression force. However, the correlation with the composite measure of spinal length does offer support to the use of stadiometry to assess the overall effect of loading.

The primary objective of this study was to determine if surgical treatment for spinal stenosis is comparable to total hip and knee arthroplasty in improving patients’ self-reported quality of life. An age, sex and time of surgery matched cohort of patients who had undergone elective primary one-two level spinal decompression (n=90) with (n=26 /90) or without fusion for spinal stenosis (n=40 with degenerative spondylolisthesis) and elective primary total hip (n=90) and knee (n = 90) arthroplasty for osteoarthritis were compared. The primary outcome measure was the preoperative and two year postoperative Medical Outcomes Study Short Form-36 (SF-36) questionnaire.

There was no significant difference in the mean pre-operative Physical Component Summary (PCS) / Mental Component Summary between groups [Spine −32/43; Hip − 30/45; Knee 31/46 (p > 0.5)]. With the exception of the knee MCS (p=0.2), postoperative scores were significantly improved for all groups [Spine −40/53; Hip − 43/51; Knee 39/48 (p < 0.001)]. Overall the hip surgery had the great impact on PCS and the spine surgery on MCS.

Studies have shown the significant impact on overall patient quality of life and cost-effectiveness of primary total joint arthroplasty. The results of this unique study show that surgical intervention for spinal stenosis has a similar positive effect at two year follow up. This study provides data that supports the need advocacy regarding waiting time initiatives and surgical resources for the treatment of patients with symptomatic spinal stenosis with a similar demographic to those with primary OA of the hip or knee.

Purpose: To determine whether skull-femoral traction is a predictor of final surgical correction in scoliosis surgery and obviates the need for anterior release in severe deformities

Methods: 20 patients underwent skeletal femoral traction with a maximum of 50% of their body weight with the use of supracondylar femoral pins. A unilateral pin was used in the presence of pelvic obliquity and bilateral pins in patients with a neutral pelvis. Counter traction was applied through Gardner Well tongs at approximately one third the weight. Pre-op radiographs were compared with dynamic films, intra-op traction films and immediate and final post-operative films. Complications related to traction were recorded. All patients underwent posterior alone surgery for their scoliosis corrections.

Results: The mean curve magnitude was 80.3 degrees. NO anterior releases were performed. Intra-operative traction provided a mean correction of 60%. Final surgical correction was 70%. Level pelvis was achieved in all patients with pelvic obliquity. Traction provided up to 80% of the final correction in older adult scoliotics (> 50 yo) thus minimizing the force required on the pedicle screws to achieve correction. No traction related complications occurred.

Conclusions: Intra-op skull-femoral traction aides in the correction of severe scoliotic curves. Excellent corrections were achieved without the need for anterior releases. Traction reduced pelvic obliquity in the neuromuscular patients. Reducing the magnitude of the curves facilitated exposure of the posterior spine and minimized forces applied to the pedicle screws during scoliosis correction.

Purpose: The purpose of this study was to demonstrate the feasibility and early outcomes of one- and two-level lumbar decompression performed as an outpatient procedure.

Methods: A retrospective review was performed comparing lumbar “laminoplasty” (bilateral decompression from a unilateral approach) using a minimally invasive (MIS-group) technique (MetRxTM tubular retractor system) to open laminoplasty (Open Group). Comparison between groups was performed for patient demographics, radiographic and operative parameters, postoperative pain (VAS), analgesic use and adverse events.

Results: A total of 67 (Open–n=37/ MIS-n=30 [n=20: out patients] patient with a minimum follow-up of 6 months were analyzed. There was no statistically significant difference between groups for age, sex, BMI and radiographic parameters. The MIS group demonstrated a statistically significant reduction (mean = 24minutes) in operative time, estimated blood loss (63mls vs. 227mls), recovery room VAS scores (1.4 vs. 4.4) and total analgesic requirements by %50. None of the MIS group procedures performed on an outpatient basis required readmission. The length of stay for the n=10 inpatient MIS group (elderly patients) was also reduced compared to the open group (2.6 vs. 4.7 days, P= 0.035). The groups were comparable in operative and postoperative adverse events. No progression of preexisting spondylolisthesis has been noted in either group during the follow-up period. Furthermore, only one patient has required reoperation for mechanical low back pain in the MIS group and one patient for recurrent leg pain in the open group.

Conclusions: Minimally invasive outpatient decompression for 1–2 level spinal stenosis is feasible, provides acute perioperative patient and resource utilization benefits and appears to have comparable short-term clinical efficacy compared to open decompression. Long-term follow-up and validated outcomes assessments are currently being assessed.

Funding : Commerical funding

Funding Parties : Medtronic-Sofamor Danek

Purpose: Report results of patients undergoing en-bloc resection of thoracic tumours with local invasion of the spinal column

Methods: Retrospective chart and outcome review

Results: The mean age was 59.1 (range 26–75) years. Patients underwent pre-operative radiation±chemotherapy. Anterior and posterior approaches were performed in all cases, staged a mean 16.2 days apart (range 4–51 days) in nine patients. There were eight non-small cell lung carcinoma, and four sarcomas. The mean total operative time was 12.8 hours(range 9–15). All patients survived the operative procedures and were discharged home. Mean hospital stay was 30.3 days(range 11–97). Positive tumour margins were present in 2 patients. Complications include need for revision thoracotomy, prolonged post-op intubation, one case of fatal PE, one superficial wound infection. Two patients died at four months post-operatively, (2/2 negative tumour margins) and one at 13 months(positive margin). Four patients were disease-free at > 1 year (range 13–40 months). The remaining patients have less than 1 yr f/u with 4/5 disease-free. Oswestry scores are 54.5 at latest f/u compared to 11.3 pre-op(p=0.007). SF-36 PCS and MCS were 35.5 and 51.1 pre-op compared to 25.6(p=0.3) and 38.3(p=0.03) post-op.

Conclusions: En-bloc resections offer curative resections at the expense of worse ODI and SF-36 scores. Staged surgeries allowed for an easier technical resection during the second stage.

Purpose: To determine the results and safety of patients undergoing|spinal cord level (SCL) pedicle subtraction osteotomy (PSO) for thetreatment of thoracic kyphosis.

Methods: Retrospective chart and radiographic review of 25 patients with severe thoracic kyphosis.

Results: The underlying diagnoses were: tumour (8), Scheuermann’s Kyphosis (4), degenerative/osteoporosis (3), fracture (3), inflammatory|(2), neurofibromatosis (2), congenital kyphosis (1), tuberculosis (1), and infected tumour (1). The osteotomy was combined with a lumbar PSO in|five patients. Three patients were treated with double thoracic|osteotomies. Two PSOs were extended transdiscally to debride the|infected disc. The mean focal PSO correction was 33.6° (range 9°–73°). The overall thoracic kyphosis measured from T5 to T12 improved from a|mean of 58.3° preoperatively to 37.1° postoperatively. Estimated blood|loss ranged from 400cc to 12500cc. All patients presenting with spinal|cord dysfunction neurologically improved postoperatively. There were 2 major neurological complications. One patient developed postoperative | progressive paraplegia following a prolonged period of intra- and | postoperative severe hypotension and coagulopathy. The other developed a| pseudoarthrosis five months postoperatively and suffered an incomplete|spinal cord injury during the subsequent revision. Other complications included: T3 radicular pain (1) -resolved; dural tears (2); respiratory failure -prolonged ICU admission(1); fractures proximal to the thoracic (2) and distal to lumbar (1) instrumentation; incomplete corrections of the sagittal alignment despite double osteotomies (2); wound breakdown associated with preoperative radiation (1).|

Conclusions: SCL-PSO is a feasible option for severe thoracic kyphosis. This procedure eliminates the need for anterior surgery; however, it does not reduce the potential for significant morbidity.

Purpose: The primary objective of this study was to determine if surgical treatment for spinal stenosis is comparable to total hip arthroplasty in improving patients’ self-reported quality of life.

Methods: An age, sex and time of surgery matched cohort of patients who had undergone elective primary 1–2 level spinal decompression (n=90) with (n=30/90) or without fusion for spinal stenosis (n=40 with degenerative spondylolisthesis) and elective primary total hip arthroplasty for osteoarthritis (n=90) were compared. The primary outcome measure was the preoperative and one year postoperative Medical Outcomes Study Short Form-36 (SF-36) questionnaire.

Results: The mean Physical Component Summary (PCS) / Mental Component Summary (MCS) for the stenosis compared to hip patients were 32.0/43.3 vs. 30.5/46.2 preoperatively (analysis between groups: p = 0.2/0.1) and 39.1/47.3 vs.44.1/46.1 postoperatively (analysis between groups: p = 0.003/0.4). The pre- and postoperative PCS significantly improved for both groups (p < 0.0001);however, the pre- and postoperative MCS improved in the stenosis group only (p = 0.04).

Conclusions: Studies have shown the significant impact on overall patient quality of life and cost-effectiveness of primary total hip arthroplasty. The results of this unique study show that surgical intervention for spinal stenosis also has a very positive overall effect on patients’ self-reported quality of life at one year follow up. This study provides data that supports the need for a long term prospective study and advocacy regarding waiting time initiatives and surgical resources for the treatment of patients with symptomatic spinal stenosis with a similar demographic to those with primary OA of the hip.

We reviewed seven patients with coronal fractures of the lateral femoral condyle and studied the mechanism of injury and the radiological features. The influence of soft tissue attachments on the displacement and the blood supply were investigated by clinical and cadaveric studies. All three fractures which were initially undisplaced lost position early during conservative management. Internal fixation gave good results at review, and is recommended to avoid the risk of malunion and possible secondary osteoarthritis.