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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_10 | Pages 34 - 34
1 Jun 2023
Airey G Chapman J Mason L Harrison W
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Introduction

Open fragility ankle fractures involve complex decision making. There is no consensus on the method of surgical management. Our aim in this study was to analyse current management of these patients in a major trauma centre (MTC).

Materials & Methods

This cohort study evaluates the management of geriatric (≥65years) open ankle fractures in a MTC (November 2020–November 2022). The method, timing(s) and personnel involved in surgical care were assessed. Weightbearing status over the treatment course was monitored. Patient frailty was measured using the clinical frailty score (CFS).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 64 - 64
1 Feb 2020
Hopwood J Redmond A Chapman G Richards L Collins S Brockett C
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Background

Total ankle arthroplasty (TAA) is an alternative to ankle arthrodesis, replacing the degenerated joint with a mechanical motion-preserving alternative. Implant loosening remains a primary cause of TAA revision, and has been associated with wear-mediated osteolysis. Differing implant designs have a major influence on the wear performance of joint replacements. Providing a range of implant sizes allows surgeons a greater intra-operative choice for varying patient anatomy and potential to minimise wear. Minimal pre-clinical testing exists in the literature that investigates the effect of implant size on the wear behaviour. The aim of this study therefore was to investigate the effect of two different implant sizes on the wear performance of a TAA.

Materials & Methods

Six ‘medium’ and six ‘extra small’ BOX® (MatOrtho Ltd, UK) TAA implants, of the same conceptual design and polyethylene insert thickness, were tested in a modified 6 station pneumatic knee simulator. 5 million cycles (Mc) of wear simulation were completed for each implant size, under kinematics aiming to replicate an ankle gait cycle (Figure 1) [1]. The simulator used had six degrees of freedom, of which four were controlled. The maximum axial load was 3150N, equivalent to 4.5 times body weight of a 70kg individual. The flexion profile ranged from −15° plantarflexion to 15° dorsiflexion. Rotation about the tibial component ranged from −2.3° of internal rotation to 8° external rotation, and anterior/posterior (AP) displacement ranged from 3.1 mm anterior to −0.9 mm posterior displacement. The lubricant used was 25% bovine serum supplemented with 0.04% sodium azide to prevent bacterial degradation. The wear of the TAA polyethylene inserts were determined gravimetrically after each Mc, with unloaded soak controls used to compensate for the uptake of moisture by the polyethylene.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 51 - 51
1 Feb 2020
Chapman R Moschetti W Van Citters D
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Introduction

Total knee arthroplasty (TKA) is highly successful due to pain reduction, patient satisfaction, and increased range of motion (ROM) during activities of daily living (ADL). ROM recovery is critical for successful outcomes, however ROM values are typically captured during routine physical therapy (PT) appointments via simplified measures (e.g. goniometric maximum passive ROM). These measures are imprecise, potentially neglecting patients’ home experiences. Accordingly, improved measurement methods are necessary to realistically represent ROM recovery. A validated inertial measurement unit (IMU) method continuously capturing knee ROM was deployed assessing knee ROM recovery during PT appointments and during patients’ routine daily experiences. Our objectives were to 1) continuously capture knee ROM pre-/post-TKA via IMUs and 2) divide each day's data to PT/non-PT segments comparing ‘gold standard’ ROM measurements (PT periods) with non-invasive home measurements (non-PT periods). Given patients are verbally/physically encouraged during PT, we hypothesized PT and non-PT metrics would be significantly different including 1) greater kinematics, 2) shorter times, and 3) greater activity level during PT compared to non-PT.

Methods

Following IRB approval, IMUs captured long duration, continuous (8–12 hours/day, ∼50 days) knee ROM pre-/post-TKA. Post-TKA metrics were subdivided to PT/non-PT time periods including maximum ROM, gait phase ROMs (stance/swing), gait times (stride/stance/swing), and activity level. Clinical ROM and patient reported outcome measures (PROMs) were also captured before/after TKA. Statistical comparisons were completed between pre-TKA, post-TKA PT, and post-TKA non-PT metrics. Correlation analyses were completed between IMU, clinical ROM, and PROMs.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 49 - 49
1 Feb 2020
Chapman R Moschetti W Van Citters D
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Introduction

With many stakeholders, healthcare decisions are complex. However, patient interests should be prioritized. This maximizes healthcare value (quality divided by cost), simultaneously minimizing costs (objective) and maximizing quality (subjective). Unfortunately, even ‘high value’ procedures like total knee arthroplasty (TKA) suffer from recovery assessment subjectivity (i.e. high assessment variability) and increasing costs. High TKA costs and utilization yield high annual expenditures (∼$22B), including postoperative physical therapy (PT) accounting for ∼10% of total costs (∼$2.3B annually). Post-TKA PT is typically homogenous across subjects ensuring most recover, however recent work shows outcomes unimpacted by PT. Accordingly, opportunities exist improving healthcare value by simultaneously reducing unnecessary PT expenditures and improving outcomes. However, discerning recovery completion relies on discrete ROM measures captured clinically and subjective clinician experience (i.e. intuition about recovery). Accordingly, our goal was developing objective post-TKA performance assessment methods utilizing gait knee ROM and statistical analyses to categorize patient recovery (‘accelerated,’ ‘delayed,’ or ‘normal’).

Methods

We first established statistical reasons for current post-TKA rehabilitation including risk-reward tradeoffs between incorrectly ascribing ‘poor recovery’ to well-recovering patients (T1 error) or ‘good recovery’ to poorly-recovering patients (T2 error) using methods described by Mudge et al. and known TKA volumes/rehabilitation costs. Next, previously captured gait ROM data from well-healed patients was utilized establishing standard recovery curves. These were then utilized to assess newly captured patient recovery. Following IRB approval, we prospectively captured gait ROM from 10 TKA patients (3M, 69±13 years) 1-week pre-TKA and 6-weeks immediately post-TKA. Performance was compared to recovery curves via control charts/Shewhart rules (daily performance) as well as standard deviation thresholds (weekly performance) establishing recovery as ‘accelerated,’ ‘delayed,’ or ‘normal.’ The categorization was extrapolated to US TKA population and savings/expenses quantified. Statistical analyses were performed in Minitab with statistical significance set to α<0.05.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 75 - 75
1 Apr 2019
Lunn D Chapman G Redmond A
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Introduction

Total hip replacement (THR) patients are often considered a homogenous group whereas in reality, patients are heterogeneous. Variation in revision rates between patient groups suggest that implants are exposed to different environmental conditions in different patients [1]. Previous reports suggest that for every unit increase of BMI, there is a 2% increased risk of revision of a THR [2]. The aim of this study was to better understand the effect of patient-specific characteristics such as BMI on hip motions and to explore the possible impact on wear.

Methods

137 THR patients, at least 12 months post-surgery, underwent 3D kinematic (Vicon, Oxford, UK) and kinetic (AMTI, USA) analysis whilst walking at self-selected walking speed. 3D kinematic data were then mapped onto a modelled femoral cup at 20 pre-determined points to create pathways for femoral head contact, which were then quantified by deriving the aspect ratio (AR). Patients were stratified into three groups determined by BMI scores; healthy weight (BMI ≤25 kg/m2) (n=34); overweight (BMI >25kg/m2 to ≤ 30 kg/m2) (n=66) and obese patients (BMI > 30 kg/m2) (n=37). Comparisons were made using 95% confidence intervals (CI) and one way ANOVAs.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 76 - 76
1 Apr 2019
Vasiljeva K Al-Hajjar M Lunn D Chapman G Redmond A Flatters I Thompson J Jones A
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Introduction

One of the known mechanisms which could contribute to the failure of total hip replacements (THR) is edge contact. Failures associated with edge contact include rim damage and lysis due to altered loading and torques. Recent study on four THR patients showed that the inclusion of pelvic motions in a contact model increased the risk of edge contact in some patients. The aim of current study was to determine whether pelvic motions have the same effect on contact location for a larger patient cohort and determine the contribution of each of the pelvic rotations to this effect.

Methods

Gait data was acquired from five male and five female unilateral THR patients using a ten camera Vicon system (Oxford Metrics, UK) interfaced with twin force plates (AMTI) and using a CAST marker set. All patients had good surgical outcomes, confirmed by patient-reported outcomes and were considered well-functioning, based on elective walking speed. Joint contact forces and pelvic motions were obtained from the AnyBody modelling system (AnyBody Technologies, DK). Only gait cycle regions with available force plate data were considered. A finite element model of a 32mm head on a featureless hemispherical polyethylene cup, 0.5mm radial clearance, was used to obtain the contact area from the contact force. A bespoke computational tool was used to analyse patients' gait profiles with and without pelvic motions. The risk of edge contact was measured as a “centre proximity angle” between the cup pole and centre of the contact area, and “edge proximity angle” between the cup pole and the furthest contact area point away from the pole. Pelvic tilt, drop and internal-external rotation were considered one at a time and in combinations.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 64 - 64
1 Feb 2017
Chapman R Kokko M Goodchild G Roche M Van Citters D
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Introduction

For nearly 58% of total knee arthroplasty (TKA) revisions, the reason for revision is exacerbated by component malalignment. Proper TKA component alignment is critical to functional outcomes/device longevity. Several methods exist for orthopedic surgeons to validate their cuts, however, each has its limitations. This study developed/validated an accurate, low-cost, easy to implement first-principles method for calculating 2D (sagittal/frontal plane) tibial tray orientation using a triaxial gyroscope rigidly affixed to the tibial plateau of a simulated leg jig and validated 2D tibial tray orientation in a human cadaveric model.

Methods

An initial simulation assessed error in the sagittal/frontal planes associated with all geometric assumptions over a range of positions (±10°, ±10°, and −3°/0°/+3° in the sagittal, frontal, and transverse planes, respectively). Benchtop experiments (total positions - TP, clinically relevant repeated measures - RM, novice user - NU) were completed using a triaxial gyroscope rigidly affixed to and aligned with the tibial tray of the fully adjustable leg-simulation jig. Finally, two human cadaveric experiments were completed. A similar triaxial gyroscope was mounted to the tibial tray of a fresh frozen human cadaver to validate sagittal and frontal plane tibial tray orientation. In cadaveric experiment one, three unique frontal plane shims were utilized to measure changes in frontal plane angle. In cadaveric experiment two, measurements using the proprosed gyroscopic method were compared with computer navigation at a series of positions. For all experiments, one rotation of the leg was completed and gyroscopic data was processed through a custom analysis algorithm.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 63 - 63
1 Feb 2017
Chapman R Van Citters D Dalury D
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Introduction

Subluxation and dislocation are frequently cited reasons for THA revision. For patients who cannot accommodate a larger femoral head, an offset liner may enhance stability. However, this change in biomechanics may impact the mechanical performance of the bearing surface. To our knowledge, no studies have compared wear rates of offset and neutral liners. Herein we radiographically compare the in-vivo wear performance of 0mm and 4mm offset acetabular liners.

Methods

Two cohorts of 40 individuals (0mm, 4mm offset highly crosslinked acetabular liners, respectively) were selected from a single surgeon's consecutive caseload. All patients received the same THA system via the posterior approach. AP radiographs were taken at 6-week (‘pre’) and 5-year (‘post’) postoperative appointments. Patients with poor radiograph quality were excluded (n0mm=5, n4mm=4). Linear and volumetric wear were quantified according to Patent US5610966A. Briefly, images were processed in computer aided design (CAD) software. Differences in vector length between the center of the femoral head and the acetabular cup (pre- and post-vector, Figure 1) allow for calculation of linear wear and wear rate. The angle (β) between the linear wear vector and the cup inclination line was quantified (Figure 1). Patients with negative β were excluded from volumetric analyses (n0mm=11, n4mm=7). Volumetric wear was accordingly calculated accounting for wear vector direction. The results from three randomly selected patients were compared to results achieved using the “Hip Analysis Suite” software package (UChicagoTech).


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_7 | Pages 22 - 22
1 May 2015
Mathews J Ward J Chapman T Khan U Kelly M
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Grade III Open fractures of the tibia represent a serious injury. It is recognised that combined management of these cases by experienced orthopaedic and plastic surgeons improves outcomes. Previous studies have not considered the timing of definitive soft tissue cover in relation to the definitive orthopaedic management. We reviewed medical notes of 73 patients with 74 Grade III Open tibia fractures (minimum 1 year follow up), to compare deep infection rates in patients who had a) a single-stage definitive fixation and soft tissue coverage vs. those who had separate operations, and b) those who had definitive treatment completed in < 72 hours vs. > 72 hours.

Of subjects that underwent definitive fixation and coverage in a single procedure, 4.2% developed deep infections, compared with 34.6 % deep infection(p<0.001) in those who underwent definitive treatment at separate operations. Of patients who had definitive treatment completed in < 72-hours, 20.0% developed deep infections a compared with 12.2%(p=0.4919) in the >72-hour group.

Patients with Gustilo III open tibial fractures have lower rates of deep infection if definitive fixation and coverage are performed in a single-stage procedure. Emphasis should be placed on timely transfer to a specialist centre, aiming for a single-stage combined orthoplastic surgery.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_5 | Pages 5 - 5
1 Mar 2014
Hassaballa M Artz N Mihok P Chapman L Robinson J Porteous A Murray J
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This is a prospective review of consecutive patients who underwent knee revision surgery using the Legion knee system.

Clinical and functional assessments (American Knee Scores-AKS, WOMAC and Oxford knee score-OKS) were carried out preoperatively, one year and 2 years post op. Radiographic evaluation was done at 1 and 2 years included review of standing AP, lateral and skyline views. Figgie's method was used to measure the joint line reproduction.

210 patients underwent revision knee system 103 male: 107 females with a mean age of 66.4 (44–87) yrs. Mean BMI-26.03 (21–50). We had a 2-year follow up for 110 patients. Surgery was carried out at a single centre and performed by Bristol knee specialists.

Indications for surgery were aseptic loosening (84), infection (27) instability (47), pain and stiffness (31), progression of disease (6), peri-prosthetic fractures (15)

The AKS and WOMAC scores at, 1 year and 2 years follow up showed significant improvements in pain and function. The mean total AKS improved from 75.7/200 pre-operatively to 140.5/200 at 2 yrs. Radiographic assessment showed a mean AP coronal femoral angle of 95.3 degrees (89.6–99.9), coronal tibial angle of 90.1 degrees (88–92). The mean sagittal femoral and tibial angles were 88.4 and 90.4 degrees respectively.

The short-term results showed significant improvement in functional and pain scores irrespective of indications for revision surgery. The Legion system has showed good outcome scores that match or beat published series on revisions. It also showed a good ability to restore joint line.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 65 - 65
1 Jan 2013
Sultan J Chapman G Jones R
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Background

The knee is the commonest joint to be affected by osteoarthritis, with the medial compartment commonly affected. Knee osteoarthritis is commonly bilateral, yet symptoms may initially present unilaterally. Higher knee adduction moment has been associated with the development and progression of medial compartment knee osteoarthritis.

Objectives

To assess the effect of lateral wedge insoles on the asymptomatic knee of patients with unilateral symptoms of medial compartment knee osteoarthritis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXII | Pages 31 - 31
1 Jul 2012
Wood A Hales R Bakker-Dyos J Chapman M Keenan A
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Previous Anterior Cruciate Ligament (ACL) reconstruction is currently a bar from entry to the Royal Marines and Royal Navy, whilst the British Army allows recruits to join if asymptomatic 18 months post ACL reconstruction. However current Royal Marines policy is to rehabilitate recruits who sustain an ACL disruption in training. We retrospectively analysed the rehabilitation times and pass out rate of Royal Marines who had an ACL disruption during recruit training over an 8 year period.

12 recruits sustained an ACL disruption during recruit training in the study period, giving an incidence of around 1.5/1000 recruits. 9 Patients underwent ACL repairs in training, with 1 patient leaving and rejoining post repair and later successfully passed out. 2 patients were treated conservatively. Of the 12 ACL sustained in training 8/12 (67%) passed out. None of the patients treated conservatively passed out. The mean time out of training for successful recruits was 51.6 weeks (95% CI 13.1) mean rehabilitation time post ACL reconstruction for successful recruits was 36.7 weeks (95% CI 12.5). Mean time to discharge for unsuccessful recruits 63.2 weeks (95% CI 42.4). In the operative group 1/10 left due to failure to return to training and 1/10 left through unrelated reasons. Current costing for recruit training is £1800 per week per recruit.

ACL injuries are not common in Royal Marine Training, and reconstruction is not a bar to completing Royal Marine basic training. We estimate that it costs around £100,000 per-injured recruit, to maintain a policy of rehabilitating ACL injured recruits in Royal Marines training. Further research into the long-term employability or Royal Marines sustaining an ACL injury in training is required.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXII | Pages 16 - 16
1 Jul 2012
Granville-Chapman J Hacker A Keightley A Sarkhel T Monk J Gupta R
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Extensor tendon ruptures have been reported in up to 8.8% of patients after volar plating and long screws have been implicated. The dihedral dorsal surface of the distal radius hinders accurate screw length determination using standard radiographic views (lateral; pronation and supination). A ‘dorsal tangential’ view has recently been described, but has not been validated.

To validate this view, we mounted a plate-instrumented sawbone onto a jig. Radiographs at different angles were reviewed independently by 11 individuals. Skyline views clearly demonstrated all screw tips, whereas only 69% of screw tips were identifiable on standard views.

With screws 2mm proud of the dorsal surface, skyline views detected 67% of long screws (sensitivity). The best of the standard views achieved only 11% sensitivity. At 4mm long, skyline sensitivity was 85%, compared with 25% for standard views. At 6mm long, 100% of long screws were detected on skylines, but only 50% of 8mm long screws were detected by standard views. Inter and intra-observer variability was 0.97 (p=0.005).

For dorsal screw length determination of the distal radius, the skyline view is superior to standard views. It is simple to perform and its introduction should reduce the incidence of volar plate-related extensor tendon rupture.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 223 - 223
1 May 2012
Petterwood J Fettke G Chapman N
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All children with a fracture of both bones of the forearm who underwent general anaesthetic manipulation and plaster (GAMP) at the Launceston General Hospital over a four-year period from 2005–2008 were reviewed. Casting technique was determined according to the treating surgeon, with three casting techniques used: flexion, extension and a mid-flexed position.

The primary end-point was defined as re-manipulation or progression to open reduction and internal fixation. The secondary end-point of residual angulation was also assessed.

A total of 123 patients with 124 fractures were treated with GAMP. Seventy-seven cases were treated in a traditional flexion cast, 28 in extension and 19 were treated in a dorsoradial slab in a mid-flexed position. Ten patients required repeat intervention. Six failures were initially cast in flexion, four were in the mid flexed position and none of the fractures in the extension group required re-manipulation. The difference between the groups was statistically significant (p<0.001).

There was significantly greater residual angulation at follow up in the flexed group compared to the extension group for both the radius (p=0.049) and the ulna (p=0.046)

Closed reduction and cast immobilisation with the elbow extended is a safe and more effective technique in maintaining position in both bone forearm fractures in children.