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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 14 - 14
16 May 2024
Davey M Stanton P Lambert L McCarton T Walsh J
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Aims

Management of intra-articular calcaneal fractures remains a debated topic in orthopaedics, with operative fixation often held in reserve due to concerns regarding perioperative morbidity and potential complications. The purpose of this study was to identify the characteristics of patients who developed surgical complications to inform the future stratification of patients best suited to operative treatment for intra-articular calcaneal fractures and those in whom surgery was highly likely to produce an equivocal functional outcome with potential post-operative complications.

Methods

All patients who underwent open reduction and internal fixation of calcaneal fractures utilizing the Sinus Tarsi approach between March 2014 and July 2018 were identified using theatre records. Patient imaging was used to assess pre- and post-operative fracture geometry with Computed Tomography (CT) used for pre-operative planning. Each patient's clinical presentation was established through retrospective analysis of medical records. Patients provided verbal consent to participation and patient reported outcome measures were recorded using the Maryland Foot Score.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 15 - 15
16 May 2024
Egglestone A Kakwani R Murty A Townshend D
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Introduction

When ankle arthroplasty fails the options are revision to arthrodesis or revision to arthroplasty. We report early outcomes of revision procedures for failed total replacement.

Methods

Retrospective review of prospectively collected data including post-operative complications, union, survivorship and PROMS scores to compare revision to arthrodesis and revision to arthroplasty.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 19 - 19
16 May 2024
Clifton L Kingman A Rushton P Murty A Kakwani R Coorsh J Townshend D
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Introduction

We report the functional outcome and survivorship of the Hintegra Total Ankle Replacement (TAR), in consecutive cases by multiple surgeons in a single UK institution. Between 2010–2014 the Hintegra TAR held 7.1% UK market share and surgeons should be aware of failure mechanisms.

Methods

We conducted a retrospective review of prospectively collected data for 70 consecutive Hintegra TAR cases in a single institution between 2010–2014. Data collected included patient demographics, complications, reoperations, patient reported outcome measures (PROMS: AOS, MOX-FQ, pain VAS) and patient satisfaction.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 20 - 20
16 May 2024
Bernasconi A Cooper L Lyle S Patel S Cullen N Singh D Welck M
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Introduction

Pes cavovarus is a foot deformity that can be idiopathic (I-PC) or acquired secondary to other pathology. Charcot-Marie-Tooth disease (CMT) is the most common adult cause for acquired pes cavovarus deformity (CMT-PC). The foot morphology of these distinct patient groups has not been previously investigated. The aim of this study was to assess if morphological differences exist between CMT-PC, I-PC and normal feet (controls) using weightbearing computed tomography (WBCT).

Methods

A retrospective analysis of WBCT scans performed between May 2013 and June 2017 was undertaken. WBCT scans from 17 CMT-PC, 17 I-PC and 17 healthy normally-aligned control feet (age-, side-, sex- and body mass index-matched) identified from a prospectively collected database, were analysed. Eight 2-dimensional (2D) and three 3-dimensional (3D) measurements were undertaken for each foot and mean values in the three groups were compared using one-way ANOVA with the Bonferroni correction.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 1 - 1
16 May 2024
Brandao B Aljawadi A Fox A Pillai A
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Objectives

Cartiva synthetic cartilage implant (SCI) is licenced for use in management of symptomatic hallux rigidus in several countries including the UK. As for now, there are no independent comparative series for treatment of hallux rigidus utilising polyvinyl alcohol implants.

Study design and methods

Patients at a single centre with symptomatic hallux rigidus who underwent Cartiva SCI implant procedure were identified. First metatarsophalangeal joint arthritis was radiographically graded according to the Hattrup and Johnson (HJ) classification. Pre-operative and post-operative patient-reported outcomes were evaluated using the Foot and Ankle Ability Measure (FAAM) activities of daily living subscale and the Manchester-Oxford Foot Questionnaire (MOXFQ).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 23 - 23
16 May 2024
McCormack D Kirmani S Aziz S Faroug R Solan M Mangwani J
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Background

Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures.

Aim

To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 5 - 5
16 May 2024
Chong H Banda N Hau M Rai P Mangwani J
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Introduction

Ankle fractures represent approximately 10% of the fracture workload and are projected to increase due to ageing population. We present our 5 years outcome review post-surgical management of ankle fractures in a large UK Trauma unit.

Methods

A total of 111 consecutive patients treated for an unstable ankle fracture were entered into a database and prospectively followed up. Baseline patient characteristics, complications, further intervention including additional surgery, functional status were recorded during five-year follow-up. Pre-injury and post-fixation functional outcome measures at 2-years were assessed using Olerud-Molander Ankle Scores (OMAS) and Lower Extremity Functional Scales (LEFS). A p value < 0.05 was considered significant.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 6 - 6
16 May 2024
Gandham S Leong E McDonnell S Molloy A Mason L Robinson A
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Introduction

Positive reports from implant designer centres on the use of fibular nails in the complex ankle fractures has resulted in a marked increase in their use nationally. Our aim in this study was to report on the outcomes of the use of all fibular nails in two major trauma centres.

Methods

All patients who underwent ankle fracture fixation using a fibular nail in two major trauma centres, were included for analysis. MTC 1 included patients from April 2013 to May 2015, and MTC 2 included patients February 2015 to March 2018. A minimum follow up of 1 year was achieved for all patients. Radiographic reduction was confirmed by Pettrones criteria at time of operation and at 6 weeks and 1 year post-operatively. Kellgren Lawrence radiographic criteria was used to classify osteoarthritis. All complications and further surgery were recorded.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 9 - 9
16 May 2024
Galhoum A Abd-Ella M ElGebeily M Rahman AA Zahlawy HE Ramadan A Valderrbano V
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Background

Charcot neuroarthropathy is a destructive disease characterized by progressive bony fragmentation as a result of the isolated or accumulative trauma in patients with decreased sensation that manifests as dislocation, periarticular fractures and instability. Although amputation can be a reasonable cost economic solution, many patients are willing to avoid that if possible. We explored here one of the salvage procedures.

Methods

23 patients with infected ulcerated unstable Charcot neuroarthropathy of the ankle were treated between 2012 and 2017. The mean age was 63.5 ±7.9 years; 16 males and 7 females. Aggressive open debridement of ulcers and joint surfaces, with talectomy in some cases, were performed followed by external fixation with an Ilizarov frame. The primary outcome was a stable plantigrade infection free foot and ankle that allows weight bearing in accommodative foot wear.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 12 - 12
16 May 2024
Tweedie B Townshend D Coorsh J Murty A Kakwani R
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Lateral approach open calcaneal osteotomy is the described gold standard procedure in the management of hindfoot deformity. With development of minimally invasive surgery, a MIS approach has been described, citing fewer wound complications and lower risk of sural nerve injury. This audit compares MIS to the traditional procedure. A retrospective review of all patients undergoing calcaneal osteotomy in Northumbria Trust in the past 5 years was performed. A total of 105 osteotomies were performed in 97 patients; 28 (13M:15F) in MIS group and 77 (40M:37F) had an open approach. The average age was 52.1 (range 16–83) for MIS and 51.5 (range 18–83) in the open group. All patients were followed up for development of wound complication, nerve injury and fusion rate. Wound complications were similar (10.7% in MIS group vs 10.3% in Open group) with no significant difference (p=0.48). Patients were treated for infection in 3(3.8%) cases in the open group and 2(7.1%) in the MIS group. This difference was not significant (p=0.43). 4 (14.3%) patients in the MIS group had evidence of sural nerve dysfunction post-operatively (managed expectantly), compared to 12(15.5%) patients in the open group (p=0.44). Of these, 2 went on to undergo neuroma exploration. There was no difference in nerve dysfunction in varus or valgus correction. Mean translation in the open group was measured as 7.3mm(SD=1.91;3 to 13mm) and 7.5mm(SD=1.25;5 to 10mm) in the MIS group. Translation was similar in varus or valgus correction. Non-union occurred in 2 patients in the MIS group and none in the open group (p= 0.06). MIS calcaneal osteotomy is a safe technique, that works as effectively as osteotomy performed through an open approach. There were lower rates of nerve injury, wound complication and infection, but this was not significantly different comparing groups. There was a higher risk of non-union in MIS technique.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 3 - 3
16 May 2024
Sinan L Kokkinakis E Kumar CS
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Introduction

Cheilectomy is a recommended procedure for the earlier stages of osteoarthritis of the 1st metatarsophalangeal joint. Although good improvement in symptoms have been reported in many studies, the long term performance of this procedure is not well understood. It is thought that a significant number of patients go onto have arthrodesis or joint replacement. We report on a large cohort of patients who received this procedure and report on the complications and mid-term outcome.

Methods

This is a retrospective study looking at all patients who underwent cheilectomy for hallux rigidus between November 2007 and August 2018. Departmental database was used to access patient details and outcome measures recorded include: postoperative wound infection, patient reported improvement in pain and the incidence of further surgical interventions like revision cheilectomy and conversion to arthrodesis and arthroplasty. X-rays were studied using PACS to stage the osteoarthritis (Hattrup and Johnson classification).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 4 - 4
16 May 2024
Yousaf S Jeong S Hamilton P Sott A
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Purpose

To explore the relationship in terms of time scale between pre-operative expectations and postoperative outcomes and satisfaction after Hallux valgus surgery.

Methods

A patient derived questionnaire was developed and 30 patients aged 19 to 67 were included undergoing primary hallux valgus correction with a first metatarsal osteotomy and distal soft tissue release. Patients were asked pre-operatively to quantify their expected time scale for improvement in pain, ability to walk unaided, ability to drive, routine foot wear and foot feeling normal at 6 weeks, 3 and 6 months following surgery, and to indicate their confidence in achieving this result. Patients recorded postoperative outcomes achieved at number of weeks. Ordinal logistic regression multivariate modelling was used to examine predictors of postoperative satisfaction.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 22 - 22
16 May 2024
Drake B Blundell M Gibson B Kingman A Kakwani R Townshend D
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Introduction

Day Case Surgery (defined as same day discharge) is a priority within the National Health Service and has been shown to provide beneficial outcomes for patients and hospitals. We report our experience developing a Day Case Programme for Total Ankle Replacement (TAR).

Methods

Prior to the introduction of a Day Case Programme, average length of stay following TAR in our unit was 3.5 days. Stakeholders were consulted about ways in which same day discharge could be facilitated. Patients' post-operative pain charts were reviewed prior to the introduction of this programme. Inclusion criteria included non-complex surgery (anticipated tourniquet < 2hrs), friend or relative support and pre-operative walking-aid assessment. An enhanced recovery protocol included long-acting popliteal block and dexamethasone. Patients were discharged with opiate analgesia and written pain instructions. Patients were asked to complete a pain and satisfaction questionnaire. Patient Reported Outcome Measures (PROMs) were recorded.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 8 - 8
16 May 2024
Giddie J Phyo N Reichert I Ahluwalia R Kavarthapu V
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Background

Corrective fusion of a deformed / unstable Charcot neuroarthropathy (CN)of the midfoot and hindfoot is performed with the aim to prevent ulcers and maintain patient mobility.

Methods

Between October 2007 and July 2018, 103 CN mid and hind foot corrections in 95 patients were performed. There were 34 hind-foot, 38 mid-foot and 31 combined hind and mid-foot surgeries. 83 feet had single stage corrections, whereas 20 required a staged operation.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 11 - 11
16 May 2024
Kendal A Brown R Loizou C Rogers M Sharp R Carr A
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Tendinopathy can commonly occur around the foot and ankle resulting in isolated rupture, debilitating pain and degenerative foot deformity. The pathophysiology and key cells involved are not fully understood. This is partly because the dense collagen matrix that surrounds relatively few resident cells limits the ability of previous techniques to identify and target those cells of interest. In this study, we apply novel single cell RNA sequencing (CITE-Seq) techniques to healthy and tendinopathic foot/ankle tendons. For the first time we have identified multiple sub-populations of cells in human tendons. These findings challenge the view that there is a single principal tendon cell type and open new avenues for further study. Healthy tendon samples were obtained from patients undergoing tendon transfer procedures; including tibialis posterior and FHL. Diseased tendon samples were obtained during debridement of intractable Achilles and peroneal tendinopathy, and during fusion of degenerative joints. Single cell RNA sequencing with surface proteomic analysis identified 10 sub-populations of human tendon derived cells. These included groups expressing genes associated with fibro-adipogenic progenitors (FAPs) as well as ITGA7+VCAM1- recently described in mouse muscle but, as yet, not human tendon. In addition we have identified previously unrecognised sub-classes of collagen type 1 associated tendon cells. Each sub-class expresses a different set of extra-cellular matrix genes suggesting they each play a unique role in maintaining the structural integrity of normal tendon. Diseased tendon harboured a greater proportion of macrophages and cytotoxic lymphocytes than healthy tendon. This inflammatory response is potentially driven by resident tendon fibroblasts which show increased expression of pro-inflammatory cytokines. Finally, identification of a previously unknown sub-population of cells found predominantly in tendinopathic tissue offers new insight into the underlying pathophysiology. Further work aims to identify novel proteins targets for possible therapeutic pathways.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 13 - 13
16 May 2024
Lambert L Davies M Mangwani J Molloy A Mason L
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Introduction

Anatomic reduction of talar body fractures is critical in restoring congruency to the talocrural joint. Previous studies have indicated a maximum of 25% talar body exposure without malleolar osteotomy. The aim of this study was to investigate the percentage talar body exposure when using the lateral transligamentous approach.

Methods

The lateral transligamentous approach to the talus was undertaken in 10 fresh frozen cadaveric specimens by surgeons inexperienced in the approach, following demonstration of the technique. An incision was made on the anterolateral aspect of the ankle augmented by the removal of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) from their fibular insertions. A bone lever was then placed behind the lateral aspect of the talus and levered forward with the foot in equinus and inversion.

The talus was disarticulated and high resolution images were taken of the talar dome surface. The images were overlain with a reproducible nine-grid division. Accessibility to each zone within the grid with a perpendicular surgical blade was documented. ImageJ software was used to calculate the surface area exposed with each approach.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 17 - 17
16 May 2024
Batten T Talbot N Sharpe I
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Revision options for a failed Total ankle arthroplasty (TAA) have historically been limited to complex hindfoot fusions, bespoke ankle arthroplasty revision or amputation. The patient outcomes of these procedures has been felt to be poor. The introduction of the INBONE-II and INVISION ankle arthroplasty revision systems has created a range of revision arthroplasty options, with the possibility of improved patient outcomes. We aim to report on the early results of 20 sequential revision TAA. All patients undergoing revision TAA with INBONE-II or INVISION had prospective collection of pre-operative and post-operative MOx-FQ and EQ-5D scores. Between September 2013 and June 2019 23 patients underwent revision TAA with mean time from implantation of 35 months (6 to 74). Those with greater than 1 year follow-up had scores included. Other outcomes included radiographic assessment for loosening and revision. 13 patients had INBONE-II and 10 INVISION. None required revision at the time of review. Pre-operative MOx-FQ averaged 40.6 (13.4 pain, 21 walking, 6.2 social). Post-operative MOx-FQ averaged 17.4 (6.2 pain, 8.1 walking, 3.1 social). Average EQ-5D improved from 8 to 6.6 and average EQ-VAS from 60 to 80. On radiograph review one patient had radiolucent lines around their INBONE-II stem evident at 1 year. This had not progressed by 4 years total follow-up. Another patient had uncoupling of part of the stem of her INBONE-II but had not required revision. This was attributed to surgeon error. Revision TAA using the INBONE-II and INVISION systems shows promising early results relating to loosening and revision and good maintained improvement in MOx-FQ and EQ-5D scores. This provides further evidence that patients with a failed TAA can safely have revision rather than having to commit to complex ankle/hindfoot fusion. This provides surgeons with flexibility particularly in those patients with other hindfoot arthritis or arthrodesis.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 16 - 16
16 May 2024
Ha T Higgs Z Watling C Osam C Madeley N Kumar C
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Introduction

Total ankle replacement (TAR) is performed for post-traumatic arthritis, inflammatory arthropathy, osteoarthritis and other indications. The Scottish Arthroplasty Project (SAP) began collection of data on TAR in 1997. In this study, using data from the SAP, we look at trends in the use and outcomes of TAR in Scotland.

Methods

We identified 499 patients from the SAP who underwent TAR between 1997 and 2015 with imaging available on the National Picture Archiving and Communication System (PACS). We identified, and looked at trends in, implant type over the following time periods: 1998–2005; 2006–2010 and 2011–2015. Age, gender, indication and outcomes for each time period were examined and also trends with implant type over time.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 18 - 18
16 May 2024
Najefi A Ghani Y Goldberg A
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Background

The importance of total ankle replacement (TAR) implant orientation in the axial plane is poorly understood with major variation in surgical technique of implants on the market. Our aims were to better understand the axial rotational profile of patients undergoing TAR.

Methods

In 157 standardised CT Scans of end-stage ankle arthritis patients planning to undergo primary TAR surgery, we measured the relationship between the knee posterior condylar axis, the tibial tuberosity, the transmalleolar axis(TMA) and the tibiotalar angle. The foot position was measured in relation to the TMA with the foot plantigrade. The variation between medial gutter line and the line bisecting both gutters was assessed.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 21 - 21
16 May 2024
Morrell R Abas S Kakwani R Townshend D
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Background

The use of a knotless TightRope for the stabilisation of a syndesmotic injury is a well-recognised mode of fixation. It has been described that the device can be inserted using a “closed” technique. This presents a risk of saphenous nerve entrapment and post-operative pain.

Aim

We aimed to establish the actual risk of injury to the Saphenous Nerve using a “closed” technique for the insertion of a TightRope.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_9 | Pages 2 - 2
16 May 2024
Schwagten K
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Background

Iatrogenic hallux varus is a rare complication after hallux valgus surgery. Operative treatment comprises a wide variety of techniques, of which the reversed transfer of the abductor hallucis tendon is the most recent described technique.

Methods

This paper will present the long-term clinical results of the reversed transfer of the abductor hallucis longus. Therefore, we performed a prospective clinical observational study on 16 female patients. Our hypothesis is that the tendon transfer will persist in a good alignment and patient satisfaction on long term. There is a 100% follow-up rate with a range from 10 to 101 months. Patients were subjected to a clinical examination, three questionnaires and their general satisfaction.


Bone & Joint Open
Vol. 5, Issue 5 | Pages 394 - 400
15 May 2024
Nishi M Atsumi T Yoshikawa Y Okano I Nakanishi R Watanabe M Usui Y Kudo Y

Aims

The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs.

Methods

Patients aged younger than 55 years diagnosed with ONFH after FNF were retrospectively reviewed. Overall, 65 hips (38 males and 27 females; mean age 32.6 years (SD 12.2)) met the inclusion criteria. Patients with stage 1 or 4 ONFH, as per the Association Research Circulation Osseous classification, were excluded. The ratios of anterior and posterior viable areas and necrotic areas of the femoral head to the articular surface were calculated by setting the femoral head centre as the reference point. The PTA was measured using Palm’s method. The association between the PTA and viable or necrotic areas of the femoral head was assessed using Spearman’s rank correlation analysis (median PTA 6.0° (interquartile range 3 to 11.5)).


Bone & Joint Open
Vol. 5, Issue 5 | Pages 385 - 393
13 May 2024
Jamshidi K Toloue Ghamari B Ammar W Mirzaei A

Aims

Ilium is the most common site of pelvic Ewing’s sarcoma (ES). Resection of the ilium and iliosacral joint causes pelvic disruption. However, the outcomes of resection and reconstruction are not well described. In this study, we report patients’ outcomes after resection of the ilium and iliosacral ES and reconstruction with a tibial strut allograft.

Methods

Medical files of 43 patients with ilium and iliosacral ES who underwent surgical resection and reconstruction with a tibial strut allograft between January 2010 and October 2021 were reviewed. The lesions were classified into four resection zones: I1, I2, I3, and I4, based on the extent of resection. Functional outcomes, oncological outcomes, and surgical complications for each resection zone were of interest. Functional outcomes were assessed using a Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 9 - 9
10 May 2024
Owen D
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Background

Increasing evidence suggests a link between the bearing surface used in total hip arthroplasty (THA) and the occurrence of infection. It is postulated that polyethylene has immunomodulatory effects and may influence bacterial function and survival, thereby impacting the development of periprosthetic joint infection (PJI). This study aimed to investigate the association between polyethylene type and revision surgery for PJI in THA using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). We hypothesized that the use of XLPE would demonstrate a statistically significant reduction in revision rates due to PJI compared to N-XLPE.

Methods

Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) spanning September 1, 1999, to December 31, 2021, were used to compare the infection revision rates between THA using N-XLPE and XLPE. We calculated the Cumulative Percentage Revision rate (CPR) and Hazard Ratio (HR) while controlling for factors like age, sex, body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, and head size.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 8 - 8
10 May 2024
Sim K Schluter D Sharp R
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Introduction

Acetabular component loosening with associated bone loss is a challenge in revision hip arthroplasty. Trabecular Metal (TM) by Zimmer Biomet has been shown to have greater implant survivorship for all-cause acetabular revision in small cohort retrospective studies. Our study aims to review outcomes of acetabular TM implants locally.

Method

This is a retrospective observational study using data from Auckland City and North Shore Hospitals from 1st of January 2010 to 31st of December 2020. Primary outcome is implant survivorship (re-revision acetabular surgery for any cause) demonstrated using Kaplan-Meier analysis. Secondary outcome is indication for index revision and re-revision surgery. Multivariate analysis used to identify statistically significant factors for re-revision surgery.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 18 - 18
10 May 2024
Joseph R Callon K Lin J Matthews B Irwin S Williams D Ashton N Crawford H Wen J Swift S Cornish J
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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.

Method

Surgery was performed on adult rats and received systemic Flucloxacillin (Flu). The craniomedial tibia was exposed, drilled, then inoculated with S. aureus biofilm. A metal pin was placed within the medullary cavity and treatments conducted. Lf in lavage solutions: The defect was subject to 2× 50 mL lavage with 4 treatment groups (saline only, Lf only, Bactisure with Lf, Bactisure with saline). Lf embedded in Stimulin beads: 4 bead types were introduced (Stimulin only, Lf only, Flu only, Lf with Flu). At day 7, rats are processed for bioluminescent and X-ray imaging, and tibial explants/pins collected for bacterial enumeration (CFU).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 29 - 29
10 May 2024
Stowers M Rahardja R Nicholson L Svirskis D Hannam J Young S
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Introduction

Day stay surgery for anterior cruciate ligament (ACL) reconstructions is an increasingly common practice and has driven clinicians to come up with postoperative pain regimes that allow same day mobilisation and a safe and timely discharge. There is a paucity of literature surrounding the use of intraosseous (IO) ropivacaine used as a Bier's block to provide both intraoperative and postoperative analgesia in lower limb surgery.

Methods

This patient blinded, pilot study randomised 15 patients undergoing ACL reconstruction to receive either IO ropivacaine 1.5 or 2.0 mg/kg; or 300 mg of ropivacaine as local infiltration (standard of care). Toxic plasma levels of ropivacaine have been defined in the literature and therefore the primary outcome for this study was arterial plasma concentration of ropivacaine as a means to determine its safety profile. Samples were taken via an arterial line at prespecified times after tourniquet deflation. Secondary outcomes that we were interested in included immediate postoperative pain scores using the visual analogue scale (VAS) and perioperative opioid equivalent consumption.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 39 - 39
10 May 2024
Zhu M Taylor G Mayo C Young S Mutu-Grigg J Poutawera V
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Aims

Hip fracture is a common injury in the elderly. Recent studies in orthopaedic access have demonstrated inequities affecting Māori. This study aimed to compare the demographic differences between Māori and NZ Europeans with hip fractures, identify any deficiencies in initial, surgical and post op care and in outcomes.

Methods

All cases in New Zealand from 2018–2020 were included. Key outcomes included time to theatre from admission, change in walking status, residential status and survival at 120 days post fracture.

Univariate analysis compared differences in demographics, surgical and management factors between ethnicities. Key outcome comparisons were conducted using multivariate analysis to assess whether ethnicity was an independent risk factor for outcomes.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 40 - 40
10 May 2024
Zhang J Miller R Chuang T
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Introduction

Distal femur fractures have traditionally been stabilized with either lateral locking plate or retrograde intramedullary nail. Dual-plates and nail-plate combination fixation have the theoretical biomechanical advantage, faster union and allows patients to weight bear immediately.

The aim of this study is to compare single vs combination fixation, and evaluate outcomes and complications.

Method

We retrospectively reviewed all patients over 60, admitted to Christchurch Hospital, between 1st Jan 2016 and 31st Dec 2022, with an AO 33A/33B/33C distal femur fracture. Patient demographics, fracture characteristics, operation details, and follow up data were recorded.

Primary outcomes are union rate, ambulatory status at discharge, and surgical complications. Secondary outcomes include quality of reduction, operation time and rate of blood transfusions.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 12 - 12
10 May 2024
Sevic A Patel C Tomlinson M
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Introduction

Comparative studies examining Fixed-Bearing (FB) and Mobile-Bearing (MB) Total Ankle Replacement (TAR) designs have demonstrated similar results and successful long-term outcomes for both. To date there has been no study directly comparing FB and MB designs of the same prosthesis. We present the first prospective randomised trial comparing patient satisfaction, functional outcomes and radiographic results of the Salto Talaris Fixed-Bearing and the Salto Mobile-Bearing Total Ankle Replacement in the treatment of end-stage ankle arthritis.

Methods

A total of 108 adult patients with end-stage ankle arthritis were enrolled in the study between November 2014 and October 2021 with similar demographic comparison. Prospective patient-reported outcomes and standardised weightbearing ankle radiographs were performed preoperatively, at 6 weeks, 6 months and 12 months post-operatively, followed by yearly intervals. All surgeries were performed by a single non-design orthopaedic foot and ankle specialist with experience in over 200 Salto and Salto Talaris TAR prior to the study. Radiographs were examined independently by two clinicians. Complete patient data and radiographs were available for 103 patients with an average follow up of 2 years.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 31 - 31
10 May 2024
Clatworthy M Rahardja R Young S Love H
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Background

Anterior cruciate ligament (ACL) reconstruction with concomitant meniscal injury occurs frequently. Meniscal repair is associated with improved long-term outcomes compared to resection but is also associated with a higher reoperation rate. Knowledge of the risk factors for repair failure may be important in optimizing patient outcomes.

Purpose

This study aimed to identify the patient and surgical risk factors for meniscal repair failure, defined as a subsequent meniscectomy, following concurrent primary ACL reconstruction.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 36 - 36
10 May 2024
Bolam SM Matheson N Douglas M Anderson K Weggerty S Londahl M Gwynne-Jones D Navarre P
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Introduction

The Te Whatu Ora Southern catchment area covers the largest geographical region in New Zealand (over 62,000 km2) creating logistical challenges in providing timely access to emergency neck of femur (NOF) fracture surgery. Current Australian and New Zealand guidelines recommend that NoF surgery be performed within 48 hours of presentation. The purpose of this study was to compare the outcomes for patients with NoF fractures who present directly to a referral hospital (Southland Hospital) compared to those are transferred from rural peripheral centres.

Methods

A retrospective cohort study identified 79 patients with NoF who were transferred from rural peripheral centres to a referral hospital for operative management between January 2011 to December 2020. This cohort was matched 1:1 by age and sex to patients with NoF who presently directly to the referral hospital over the same period. The primary outcome was to compare time to surgery between the groups and secondary outcomes were to compare length of hospital stay, complication rates and mortality rates at 30-days and 1-year.


Introduction

The first VRAS TKA was performed in New Zealand in November 2020 using a Patient Specific Balanced Technique whereby VRAS enables very accurate collection of the bony anatomy and soft tissue envelope of the knee to plan and execute the optimal positioning for a balanced TKA

Method

The first 45 VRAS patients with idiopathic osteoarthritis of the knee was compared with 45 sequential patients who underwent the same TKA surgical technique using Brainlab 3 which the author has used exclusively in over 1500 patients. One and two year outcome data will be presented


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 2 - 2
10 May 2024
Chen W Tay ML Bolam S Rosser K Monk AP Young SW
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Introduction

A key outcome measured by national joint registries are revision events. This informs best practice and identifies poor-performing surgical devices. Although registry data often record reasons for revision arthroplasty, interpretation is limited by lack of standardised definitions of revision reasons and objective assessment of radiologic and laboratory parameters. Our study aim was to compare reasons for unicompartmental knee arthroplasty (UKA) revision reported to the New Zealand Joint Registry (NZJR) with reasons identified by independent clinical review.

Methods

A total of 2,272 patients undergoing primary medial and lateral UKA at four large tertiary hospitals between 2000 and 2017 were included. A total of 158 patients underwent subsequent revision with mean follow-up of 8 years. A systematic review of clinical findings, radiographs and operative data was performed to identify revision cases and to determine the reasons for revision using a standardised protocol. These were compared to reasons reported to the NZJR using Chi-squared and Fisher exact tests.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 23 - 23
10 May 2024
Leary J Lynskey T Muller A
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Objective

Carpal tunnel release surgery is a commonly performed procedure for alleviating symptoms of median nerve compression and restoring hand function. With pressure on theatre time these procedures are now commonly performed in a step-down out-patient facility under local anaesthetic. The choice of suture for skin closure in this procedure can impact the quality of wound healing, patient outcomes and the follow-up required however the question of the best type of suture remains unanswered. The purpose of this study was to compare the outcomes of absorbable and non-absorbable sutures using a randomised control trial design.

Methods

Eighty patients diagnosed with bilateral carpal tunnel syndrome were enrolled and underwent outpatient carpal tunnel release surgery under local anaesthetic in a staged fashion. Random number generation was used to assign each hand to receive interrupted nylon or Vicryl Rapide sutures. Pre-operative data collection included patient demographics, ASA, inflammatory conditions, smoking status as well as a Boston Carpal Tunnel Questionnaire (BCTQ) for each hand. Patients were followed up at 2 and 6 weeks after each operation and the BCTQ was repeated along with the Patient and Observer Scar Assessment Scale and the VAS score for wound discomfort. This study has approval from the DHB ethics committee, Local Iwi, HDC and ANZ Clinical Trials:ACTRN12623000100695.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 26 - 26
10 May 2024
Mauiliu S
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Titanium Elastic Nails have been around for the last 40 years, but it has never been introduced properly in the Pacific especially in Samoa in the management of femoral & in severely displaced forearm fractures in the paediatric age group & also Adult upper limb Trauma.

This paper looks at the cases treated in TTM Hospital (Apia, Samoa) from June 2019- June 2023, looking at common injury patterns, indications for fixation and the cost benefit to the family and hospital, in terms of early rehabilitation and improving the length of stay in hospital pre-Tens nail era from 6–8 weeks to 1–2 weeks in hospital. 29 cases were treated with TENs concept during this period, 17 femoral fractures, 10 forearm fractures & 1 humerus fracture.

Lastly this is very useful skill and tool to have in every hospital in the Pacific Islands, through proper training to prevent long term complications.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 6 - 6
10 May 2024
Zaidi F Bolam S Goplen C Yeung T Lovatt M Hanlon M Munro J Besier T Monk A
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Introduction

Robotic-assisted total knee arthroplasty (TKA) has demonstrated significant benefits, including improved accuracy of component positioning compared to conventional jig-based TKA. However, previous studies have often failed to associate these findings with clinically significant improvements in patient-reported outcome measures (PROMs). Inertial measurement units (IMUs) provide a more nuanced assessment of a patient's functional recovery after TKA. This study aims to compare outcomes of patients undergoing robotic-assisted and conventional TKA in the early postoperative period using conventional PROMS and wearable sensors.

Method

100 patients with symptomatic end-stage knee osteoarthritis undergoing primary TKA were included in this study (44 robotic-assisted TKA and 56 conventional TKA). Functional outcomes were assessed using ankle-worn IMUs and PROMs. IMU- based outcomes included impact load, impact asymmetry, maximum knee flexion angle, and bone stimulus. PROMs, including Oxford Knee Score (OKS), EuroQol-Five Dimension (EQ-5D-5L), EuroQol Visual Analogue Scale (EQ-VAS), and Forgotten Joint Score (FJS-12) were evaluated at preoperative baseline, weeks 2 to 6 postoperatively, and at 3-month postoperative follow-up.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 3 - 3
10 May 2024
Hancock D Leary J Kejriwal R
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Introduction

This study assessed outcomes of total knee joint replacements (TKJR) in patients who had undergone previous periarticular osteotomy compared with unicompartmental knee replacement (UKR). Establishing a difference in the results of total knee joint replacements following these operations may be an important consideration in the decision-making and patient counselling around osteotomy versus UKR for the management of single-compartment osteoarthritis.

Method

Using data from the New Zealand Joint Registry, we identified 1,895 total knee joint replacements with prior osteotomy and 1,391 with prior UKR. Revision rates and patient-reported outcomes, as measured by the Oxford Knee Score (OKS), between these two groups were compared. Adjusted hazard ratios were also calculated to compare the groups.


Concepts in glenoid tracking and treatment strategies of glenoid bone loss are well established. Initial observations in our practice in Singapore showed few patients with major bone loss requiring glenoid reconstructions. This led us to investigate the incidence of and the extent of bone loss in our patients with shoulder instability. Our study revealed bony Bankart lesions were seen in 46% of our patients but glenoid bone loss measured only 6–10% of the glenoid surface. In the same study we found that arthroscopic labral repair with capsular plication and Mason-Ellen suturing (Hybrid technique) was sufficient to stabilise patients with bipolar bone defects and minor glenoid bone loss. This led us to develop the concept of minor bone loss and a new algorithm.

Our algorithm and strategies to deal with major bone loss will also be discussed, and techniques & outcomes of Arthroscopic Bony Bankart repair, Arthroscopic Glenoid Reconstruction and Arthroscopic Remplissage procedures will be shown.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 10 - 10
10 May 2024
Penumarthy R Jennings A
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Background

Obesity has been linked with increased rates of knee osteoarthritis. Limited information is available on the survival and functional outcome results of rTKR in the obese patients. This registry-based study aimed to identify whether BMI is an independent risk factor for poorer functional outcomes and /or implant survival in rTKA.

Methods

New Zealand Joint Registry (NZJR) data of patients who underwent rTKA from 1st January 2010 to January 2023 was performed. Demographics, American Society of Anesthesiologists (ASA), BMI, Operative time, indications for revision and components revised of the patients undergoing rTKA was collected. Oxford knee score (OKS) at 6 months and rates of second revision (re- revision) were stratified based on standardised BMI categories.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 21 - 21
10 May 2024
Tuimana C Asafo A Hunter S Chan G
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Pacific people in New Zealand experience significant disparity in health outcomes. There is little known about the burden of arthritis within this community or difficulties accessing specialist orthopaedic care. This qualitative study evaluated the experiences of Pacific patients who underwent hip or knee arthroplasty with a goal to identify barriers to accessing arthroplasty for this community.

We interviewed Pacific patients within the Bay of Plenty region who had received either elective hip or knee arthroplasty between 2013 and 2022. Interviews were centred on perceptions of arthritis severity, duration of symptoms, primary care and specialist interactions. Patients were encouraged to offer feedback on ways to improve this experience.

We identified 6087 publicly funded primary joints performed in Tauranga hospital and 58 patients were of Pacific ethnicity. After exclusion criteria was applied, we successfully interviewed 20 patients eligible for our study. Pacific patients represented 2.9% of the of the BOP catchment but only received 0.43% of the publicly funded joints. Most reported reluctance to seek help from primary care until symptoms were present for at least a year. Most commonly cited reasons for not seeking help were fear of hospital services and lack of awareness in the community about osteoarthritis.

We identified a lack of community awareness of osteoarthritis and arthroplasty among Pacific. This may result in delayed presentation to primary care and decreased utilisation of publicly funded joint surgery. It is reassuring that most patients of Pacific ethnicity who receive primary hip or knee arthroplasty report a positive experience. Public health initiatives together with positive feedback from Pacific patients who have undergone surgery will help to increase awareness of arthroplasty as an option to restore function and relieve pain.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 34 - 34
10 May 2024
Penumarthy R Turner P
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Aim

Clavicular osteotomy was described as an adjunct to deltopectoral approach for improved exposure of the glenohumeral joint. This study aims to present contemporary outcomes and complications associated with the routine use of clavicular osteotomy by a single surgeon in a regional setting within New Zealand.

Methods

A retrospective case series of patients who have undergone any shoulder arthroplasty for any indication between March 2017 to August 2022. This time period includes all patients who had clavicular osteotomy(OS) and patients over an equal time period prior to the routine use of osteotomy as a reference group (N-OS).

Oxford Shoulder Score (OSS) and a Simple Shoulder Test (STT) were used to assess functional outcomes and were compared with the reported literature. Operative times and Complications were reviewed.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 11 - 11
10 May 2024
Stowers M Slykerman L McClean L Senthi S
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Introduction

A common acute orthopaedic presentation is an ulcerated or infected foot secondary to diabetic neuropathy. Surgical debridement or amputation are often required to manage this complication of diabetes. International literature indicates that amputation may lead to further complications and an increased mortality rate. The aim of this study is to investigate the mortality rate associated with different surgical interventions. This will inform surgical management of patients presenting with acute foot complications from diabetes.

Methods

This is a retrospective review of patients with diabetic foot infections aged >16 years attending Middlemore Hospital over a 10-year period (2012–2021). Clinical records were examined to determine whether patients were managed with no surgery, surgery but not amputation, or amputation. We recorded relevant baseline characteristics and comorbidities. Regression models were used to determine factors associated with mortality.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 1 - 1
10 May 2024
Scherf E Willis J Frampton C Hooper G
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Introduction

The mobile-bearing (MB) total knee arthroplasty (TKA) design was introduced with the aim of reducing polyethylene wear and component loosening seen in the fixed-bearing (FB) design. A recent joint registry study has revealed increased risk for all-cause revision, but not revision for infection, in MB-TKA. We used the New Zealand Joint Registry (NZJR) to compare all-cause revision rates, and revision rates for aseptic loosening of MB-TKA compared with fixed bearing (FB) TKA.

Methods

All patients who underwent a primary TKA registered in the NZJR between the 1st January 1999 to 31st December 2021 were identified. Analysis compared MB to FB designs, with sub analysis of implants from a single company. We identified 135,707 primary TKAs, with 104,074 (76.7%) FB-TKAs and 31,633 (23.3%) MB-TKAs recorded. We examined all-cause revision rates, reasons for revision and performed survival analyses.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 4 - 4
10 May 2024
Hoffman T Knudsen J Jesani S Clark H
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Introduction

Debridement, antibiotics irrigation and implant retention (DAIR) is a common management strategy for hip and knee prosthetic joint infections (PJI). However, failure rates remain high, which has led to the development of predictive tools to help determine success. These tools include KLIC and CRIME80 for acute-postoperative (AP) and acute haematogenous (AH) PJI respectively. We investigated whether these tools were applicable to a Waikato cohort.

Method

We performed a retrospective cohort study that evaluated patients who underwent DAIR between January 2010 and June 2020 at Waikato Hospital. Pre-operative KLIC and CRIME80 scores were calculated and compared to success of operation. Failure was defined as: (i) need for further surgery, (ii) need for suppressive antibiotics, (iii) death due to the infection. Logistic regression models were used to calculate the area under the curve (AUC).


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 32 - 32
10 May 2024
Wells Z Zhu M Sim K Schluter D Young SW
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Objectives

Post-infective arthritis is an important sequalae of septic arthritis(SA). While total knee arthroplasty(TKA) is an effective treatment for said arthritis, previous SA brings challenges for treatment planning. Using prospectively collected data from a cohort of patients with knee SA, this study aims to determine the proportion of patients requiring eventual TKA, and risk factors of developing prosthetic joint Infection(PJI).

Methods

All cases of 1st episode knee SA from 01/01/2000 to 31/12/2020 were identified in the Auckland region. Patient records and NZJR records of all cases were searched to identify subsequent TKA. PJI following arthroplasty was identified using ICM criteria.

Univariate and multivariate analysis was performed to determine risk factors for developing PJI.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 37 - 37
10 May 2024
Woodfield T Major G Longoni A Simcock J Hooper G Lim K
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Introduction

Autologous fat grafting has favourable potential as a regenerative strategy and is the current gold-standard to repair large contour defects, as needed in breast reconstruction after mastectomy and traumatic soft tissue reconstruction. Clinically, there is a limit on the volume of lipoaspirate which can be utilised to repair a soft-tissue defect. Surgical complications are the result of poor structural fidelity of lipoaspirate and graft resorption as a filling material and are hindered further by poor graft vascularisation. This study aims to develop injectable lipoaspirate-derived adipose tissue grafts with enhanced biologically and clinically-admissible structural and functional properties adopting light photocrosslinking of unmodified lipoaspirate.

Methods

Patient-derived lipoaspirate was harvested and crosslinked using novel photoinitiator and exposure to visible light (wavelength 450nm) in surgery, establishing bonds between extracellular matrix (ECM) proteins within the material. The degree of crosslinking was tuned (photoinitiator concentration, light exposure, light intensity) and covalent bond formation measured using mass spectrometry. To predict patient response, SWATH-MS was used to identify differences in patient ECM and crosslinked grafts were implanted in vivo using a subcutaneous mouse model. Functional vessel formation and resorption were quantified using micro-CT and tissue-remodelling was assessed via histology.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 38 - 38
10 May 2024
Zhu M Mayo C Rahardja C Seow MY Young S
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Aims

Using the Australian and New Zealand Hip Fracture Registry (ANZHFR) data, this study aimed to identify patient, fracture, and management factors associated with survival, mobility and residential status at 120 days. This will allow future interventions to target modifiable risk factors to improve the overall care of patients with hip fractures.

Methods

All NZ patients from 2018 – 2020 were included. Baseline demographics, management factors, and outcomes were recorded. Key outcomes were change in walking status, residential status and survival at 120 days. Univariate analysis was performed to compare differences in demographics, surgical and management factors for the key variables. Multivariate analysis was conducted to identify factors independently associated with outcomes.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 19 - 19
10 May 2024
Earp J Hadlow S Walker C
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Introduction

This study aimed to assess the relationship between preparation times and operative procedures for elective orthopaedic surgery. A clearer understanding of these relationships may facilitate list organisation and thereby contribute to improved operating theatre efficiency.

Methods

Two years of elective orthopaedic theatre data was retrospectively analysed. The hospital medical information unit provided de- identified data for 2015 and 2016 elective orthopaedic cases, from which were selected seven categories of procedures with sufficient numbers to allow further analysis - primary hip and knee replacement, spinal surgery, shoulder surgery (excluding shoulder replacement), knee surgery, foot and ankle surgery (excluding ankle replacement), Dupuytrens surgery and general orthopaedic surgery. The data analysed included patient age, ASA grade, operation, operation time, and preparation time (calculated as the time from the start of the anaesthetic proceedings to the patient's admission to Recovery, with the operating time [skin incision to skin closure] subtracted). Statistical analysis of the data was undertaken.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 15 - 15
10 May 2024
Longoni A Arnold S Major GS Jiang A Wise L Hooper G Kieser D Woodfield T Rnjak-Kovacina J Lim K
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INTRODUCTION

Stimulation of angiogenesis via the delivery of growth factors (GFs) like vascular endothelial growth factor (VEGF) is a promising strategy for the treatment of avascular necrosis (AVN). Tyraminated poly-vinyl-alcohol hydrogels (PVA-Tyr), which have the ability to covalently incorporate GFs, were proposed as a platform for the controlled delivery of therapeutic levels VEGF to the necrotic areas[1]. Nevertheless, PVA hydrophilicity and bioinertness limits its integration with the host tissues. The aim of this study was to investigated the effectiveness of incorporating gelatin, an FDA-approved, non-immunogeneic biomaterial with biological recognition sites, as a strategy to facilitate blood vessels invasion of PVA-Tyr hydrogels and to restore the vascular supply to necrotic tissues.

METHODS

Progressively higher gelatin concentrations (0.01–5wt%) were incorporated in the PVA-Tyr network. Hydrogel physico-chemical properties and endothelial cell attachment were evaluated. Afterwards, the capability of the released VEGF and gelatin to promote vascularization was evaluated via chorioallantoic membrane (CAM) assay. VEGF-loaded PVA-Tyr hydrogels with or without gelatin (n=7) were implanted in a subcutaneous mouse model for 3 weeks. Vascularization (CD31+ cells) and cell infiltration (H&E) were evaluated. Finally, AVN was induced in 6 weeks old male piglets as previously described [2]. A transphyseal hole (3mm) was drilled and PVA-Tyr hydrogels with 1% gelatin were delivered in the defects. Piglets were euthanized after 4 weeks and microCT analysis was performed.