Introduction

Major trauma during military conflicts involve heavily contaminated open fractures. Staphylococcus aureus (S. aureus) commonly causes infection within a protective biofilm. Lactoferrin (Lf), a natural milk glycoprotein, chelates iron and releases bacteria from biofilms, complimenting antibiotics. This research developed a periprosthetic biofilm infection model in rodents to test an Lf based lavage/sustained local release formulation embedded in Stimulin beads.

7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.

Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-years follow-up. Demographic data, instrumented levels and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage and pain levels were evaluated.

Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1–2 and four Lenke 3–6. Five patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for two LIV was distal to the LTV; for two, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.

The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis

In 2010, we published results of Ponseti versus primary posteromedial release (PMR) for congenital talipes equinovarus (CTEV) in 51 prospective patients. This study reports outcomes at a median of 15 years from original treatment.

We followed 51 patients at a median of 15 years (range 13–17 years) following treatment of CTEV with either Ponseti method (25 patients; 38 feet) or PMR (26 patients; 42 feet). Thirty-eight patientsd were contacted and 33 participated in clinical review (65%), comprising patient reported outcomes, clinical examination, 3-D gait analysis and plantar pressures.

Sixteen of 38 Ponseti treated feet (42%) and 20 of 42 PMR treated feet (48%) had undergone further surgery. The PMR treated feet were more likely to have osteotomies and intra- articular surgeries (16 vs 5 feet, p<0.05). Of the 33 patients reviewed with multimodal assessment, the Ponseti group demonstrated better scores on the Dimeglio (5.8 vs 7.0, p<0.05), the Disease Specific Instrument (80 vs 65.6, p<0.05), the Functional Disability Inventory (1.1 vs 5.0, p<0.05) and the AAOS Foot & Ankle Questionnaire (52.2 vs. 46.6, p < 0.05), as well as improved total sagittal ankle range of motion in gait, ankle plantarflexion range at toe off and calf power generation. The primary PMR group displayed higher lateral midfoot and forefoot pressures.

Whilst numbers of repeat surgical interventions following Ponseti treatment and primary PMR were similar, the PMR treated feet had greater numbers of osteotomies and intra-articular surgeries. Outcomes were improved at a median of 15 years for functional data for the Ponseti method versus PMR, with advantages seen in the Ponseti group over several domains. This study provides the most comprehensive evaluation of outcomes close to skeletal maturity in prospective cohorts, reinforcing the Ponseti Method as the initial treatment of choice for idiopathic clubfeet

This study aimed to identify long-term physical and psychosocial health outcomes in children with overwhelming musculoskeletal sepsis.

Children admitted to the Paediatric Intensive Care Unit (PICU) from 1st January 2002 to 31st December 2017 with a musculoskeletal focus of infection were identified. A medical notes review was completed to determine survival and morbidity. Present-day clinical assessment of the musculoskeletal and respiratory systems along with questionnaires on health-related quality of life, mental health and sleep were performed.

70 patients were identified over 15 years. Seven children died acutely (five Pasifika and two Māori children) indicating 10% mortality. Recurrence/chronic infection affected 23%. Growth disturbance affected 18%. The hip joint and proximal femur suffered the worst long-term complications. Children under 2 years most at risk of long-term disability. No patients had chronic respiratory illness beyond 90 days. Fifteen children had symptoms of acute neurological impairment, three of whom had permanent acquired brain injury. Twenty-six survivors (41%) were assessed a mean of 8.2 years (SD 4.5, range 2– 18 years) after discharge. Health-related quality of life scores were on par with normative data. All patients who underwent pulmonary function tests had normal results. Six patients and eight parents screened positive for moderate to severe post-traumatic stress disorder.

Paediatric multifocal musculoskeletal sepsis can result in complex illness with multi-organ complications for some children. Māori and Pasifika children are most at risk. Children under 2 years and those with proximal femur and/or hip involvement are most likely to have chronic musculoskeletal sequelae and permanent disability. Other outcomes are favourable with no evidence of chronic lung disease or mean reduced quality of life. A period of rehabilitation for children with identified acquired brain injury should be part of discharge planning.

Augmented reality simulators offer opportunities for practice of orthopaedic procedures outside of theatre environments. We developed an augmented reality simulator that allows trainees to practice pinning of paediatric supracondylar humeral fractures (SCHF) in a radiation-free environment at no extra risk to patients. The simulator is composed of a tangible child's elbow model, and simulated fluoroscopy on a tablet device. The treatment of these fractures is likely one of the first procedures involving X-ray guided wire insertion that trainee orthopaedic surgeons will encounter. This study aims to examine the extent of improvement simulator training provides to real-world operating theatre performance.

This multi-centre study will involve four cohorts of New Zealand orthopaedic trainees in their SET1 year. Trainees with no simulator exposure in 2019 - 2021 will form the comparator cohort. Trainees in 2022 will receive additional, regular simulator training as the intervention cohort. The comparator cohort's performance in paediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a six-month period. The performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to examine whether additional training with an augmented reality simulator shows improved real-world surgical outcomes compared to traditional surgical training. This protocol has been approved by the University of Otago Health Ethics committee, and the study is due for completion in 2024.

This study is the first nation-wide transfer validity study of a surgical simulator in New Zealand. As of September 2022, all trainees in the intervention cohort have been recruited along with eight retrospective trainees via email. We present this protocol to maintain transparency of the prespecified research plans and ensure robust scientific methods. This protocol may also assist other researchers conducting similar studies within small populations.

Survival of sepsis has been documented worldwide, but little is documented about the long-term health outcomes of multifocal sepsis from acute musculoskeletal infection - the first study of its kind in New Zealand.

Children admitted to the Paediatric Intensive Care Unit (PICU) from 1^st January 2002 to 31^st December 2017 with a musculoskeletal focus of infection were identified from hospital coding data. Notes review from discharge to present day determined survival and morbidity. Present-day clinical assessment of the musculoskeletal and respiratory systems along with questionnaires on health-related quality of life, mental health and sleep were performed.

Seventy patients were studied. Seven children died acutely (five Pasifika and two Māori children) indicating 10% mortality. Long-term survival was favourable with no recorded deaths after discharge. Recurrence/chronic infection occurred in 23%, a mean of 1.1 year after discharge. Growth disturbance occurred in 18%, a mean of 3 years after discharge. The hip joint and proximal femur have the worst complications. Children under 2 years are most at risk of long-term disability. No patients had chronic respiratory illness beyond 90 days. Fifteen children had symptoms of acute neurological impairment, three of whom had permanent brain injury. Twenty-six survivors (41%) were assessed a mean of 8.2 years after discharge. Health-related quality of life scores were on par with normative data. Six patients and eight parents screened positive for moderate to severe post-traumatic stress disorder.

Paediatric multifocal musculoskeletal sepsis can result in complex illness with long hospital stay and multi-organ complications. Māori and Pasifika children, those under two and those involving the proximal femur/or hip are most at risk. Other outcomes are favourable with no evidence of chronic lung disease or poor quality of life. A period of rehabilitation for children with identified acquired brain injury should be part of discharge planning.

The purpose of this study is to evaluate risk factors for distal construct failure (DCF) in posterior spinal instrumented fusion (PSIF) in adolescent idiopathic scoliosis (AIS). We observed an increased rate of DCF when the pedicle screw in the lowest instrumented vertebra (LIV) was not parallel to the superior endplate of the LIV, however this has not been well studied in the literature. We hypothesise a more inferiorly angled LIV screw predisposes to failure and aim to find the critical angle that predisposes to failure.

A retrospective cohort study was performed on all patients who underwent PSIF for AIS at the Starship Hospital spine unit from 2010 to 2020. On a lateral radiograph, the angle between the superior endplate of the LIV was measured against its pedicle screw trajectory. Data on demographics, Cobb angle, Lenke classification, instrumentation density, rod protrusion from the most inferior screw, implants and reasons for revision were collected.

Of 256 patients, 10.9% (28) required at least one revision. The rate of DCF was 4.6% of all cases (12 of 260) and 25.7% of revisions were due to DCF. The mean trajectory angle of DCF patients compared to all others was 13.3° (95%CI 9.2° to 17.4°) vs 7.6° (7° to 8.2°), p=0.0002. The critical angle established is 11°, p=0.0076. Lenke 5 and C curves, lower preoperative Cobb angle, titanium only rod constructs and one surgeon had higher failure rates than their counterparts. 9.6% of rods protruding less than 3mm from its distal screw disengaged.

We conclude excessive inferior trajectory of the LIV screw increases the rate of DCF and a screw trajectory greater than 11° predisposes to failure. This is one factor that can be controlled by the surgeon intraoperatively and by avoiding malposition of the LIV screw, a quarter of revisions can potentially be eliminated.

Developmental dysplasia of the hip (DDH) may lead to premature degenerative arthritis requiring total hip arthroplasty (THA). There is general concern that THA survival in DDH is inferior to that of the general population. We have investigated the results of primary THA performed in patients with DDH in New Zealand.

Through the New Zealand Joint Registry we identified all patients with DDH undergoing primary THA (n = 1205) and all patients with primary osteoarthritis (OA) undergoing primary THA (n = 40589) between 1 January 1999 and 31 December 2008. Postoperative outcomes (including six month Oxford Hip Score (OHS), revision rate, and six month mortality) were analysed and compared between the DDH and the OA groups. Baseline information and operative characteristics were also compared between the two patient groups.

There was no statistically significant difference in six month OHS between the DDH and OA groups from the uncorrected comparison (mean 41.5 vs. 40.8, p=0.056) and from the comparison corrected for known confounding variables (p=0.54). There was no statistically significant difference in revision rate between the DDH and OA groups from the uncorrected comparison (0.79 vs. 0.61 revisions per 100 component years, p=0.121) and from the comparison corrected for known confounding variables (p=0.674). There was no statistically significant difference in six month mortality between the DDH and OA groups from the uncorrected comparison (0.5% vs. 0.8%, p=0.284), however the corrected comparison identified a higher mortality rate in the DDH group (p=0.016).

The DDH group was significantly younger (49.3 years vs. 67.6 years, p<0.001), more often female (74% vs. 52%, p<0.001) and had a lower ASA class (p<0.001) than the OA group. The right hip was involved most often (51% DDH, 54% OA, p=0.03). Bone grafting (4% vs. 0.9%, p<0.001) and uncemented implants (68.3% vs. 28.1%, p<0.001) were more common in the DDH group. Surgical approach did not differ substantially between groups. The DDH group required a longer operative time than the OA group (mean 94.4 minutes vs. 79.7 minutes, p<0.001).

THA in patients with DDH patients is demanding. Despite the complexities inherent to THA in these patients, comparable functional outcomes and revision rates to patients with OA can be expected. Our results supports THA as a successful surgical option for the management of degenerative hip arthritis in patients with DDH.