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Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_6 | Pages 23 - 23
1 May 2019
Tsang B Clarke A Dobson P Thomas P Jameson S Baker P
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Background

There is significant variation and inconsistencies in the current advice and information delivered to patients undergoing total hip replacement (THR). The aim of this study was to assess a locally developed web-based electronic resource system for patients undergoing total hip replacement (THR) surgery to see if this improves and standardises the content, structure, and delivery of information delivered to patients prior to and after surgery.

Patients/Materials and Methods

Prospective study with patients recruited in clinic when listed for THR surgery. Patients are emailed login details for the web based electronic resource system (GoWellHealth). The platform delivers content in a time-lined fashion and is individualised to the patient. Data gathered includes the number of patients registering to use this system, their engagement and use of the resources, and results from forms and questionnaires administered.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_14 | Pages 66 - 66
1 Nov 2018
Summer B Schwarzenlander K Reyna AP Thomas P Kretzer P Vas A Grupp T
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Total knee arthroplasty is a well-established treatment for degenerative joint disease, on the other hand metal ion release of cobalt or chromium and particle formation can trigger intolerance reactions. Biotribological examinations can help to assess the metal ion release in different settings. The purpose of this study was the evaluation of inter-laboratory differences in the metal ion concentration analysis. Samples were generated in a 3+1 station knee wear simulator (EndoLab GmbH, Thansau, Germany) with a medium size Columbus Knee System with or without AS multilayer coating. The wear simulation was performed under highly demanding activity (HDA) profile and samples were taken after 0.5, 5.0, 5.5. and 8.0 million cycles. The samples were blinded and sent to three different laboratories and the content of chromium, cobalt, molybdenum, nickel, and zirconium was assessed by inductively coupled plasma mass spectrometry (ICP-MS). The AS multilayer coating clearly reduced the release of chromium, cobalt and molybdenum. Mean levels were: Chromium 9329.78µg/l ± 985.44 vs 503.75µg/l ± 54.19, cobalt 10419.00µg/l ± 15.517.53 vs 2.60µg/l ± 1.35, molybdenum 2496.33µg/l ± 102.62 vs 2.46µg/l ± 2.31. Interestingly we found especially for nickel and zirconium big inter-laboratory differences in the metal assessment. There were up to 10-fold higher values in comparison of one laboratory to another. The data demonstrate that results of metal ion assessment should be evaluated by interlaboratory comparison and should be critically interpreted.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 48 - 48
1 Apr 2018
Reyna ALP Fritz B Schwiesau J Summer B Thomas P Grupp TM
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Total knee arthroplasty is a well established treatment for degenerative joint disease with good clinical results. However, complications may occur due to a biological response to polyethylene wear particles, leading to osteolysis and aseptic loosening, as well as local and systemic hypersensitivity reactions triggered by metal ions and particles such as chromium, cobalt and molybdenum. Moreover, there is an increasing demand on the performance of these implants, as this treatment is also performed in heavier, younger and middle-aged adults who have a significant physical activity and higher life expectancy. The purpose of the following study was to compare the wear characteristics and performance of a zirconium nitride (ZrN) coated knee implant, designed for patients with metal ion hypersensitivity, against the clinically established cobalt-chromium (CoCr) version under a high demanding activities wear simulation.

Medium size AS Columbus® DD (Aesculap AG, Tuttlingen, Germany) femoral and tibial components with a ZrN surface were tested in comparison with the cobalt-chromium version Columbus® DD. For both groups, ultra-high-molecular weight polyethylene (UHMWPE) gliding surfaces (size T3, high 10 mm) were used. Wear simulation was performed on a load controlled 4 station knee wear simulator (EndoLab GmbH, Thansau, Germany) capable of reproducing loads and movement of daily activities measured in vivo (Bergmann et al, 2014) on 8 patients and normalized to a patient weight of 100 kg (Schwiesau et al, 2014). The load profiles were applied for 5 million cycles in a combination of 40% stairs up, 40% stairs down, 10% level walking, 8% chair raising and 2% deep squatting. Test serum was changed every 0.5 million cycles and all the components were cleaned and analyzed according to ISO 14243-2:2009(E). The gliding surfaces were evaluated for gravimetric wear and wear patterns, femur components analyzed for scratches and the test medium analyzed for metal ion concentration (cobalt, chromium, molybdenum and zirconium) using ICP-MS according to ISO 17294-2.

The present study showed a wear rate reduction for the ZrN group (1.01 ± 0.29 mg/million) in comparison with the CoCr group (2.40 ± 1.18 mg/million cycles). The articulation surface of the ZrN coated femurs remained polished after the testing period, whereas the uncoated femurs showed wear scratches. Furthermore, the metal ion release from the ZrN coated implants was reduced orders of magnitude in comparison with the CoCr implants through the entire test. These results demonstrate the efficiency of ZrN coated knee implants to reduce wear as well as to prevent metal ion release in the knee joint.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_6 | Pages 35 - 35
1 Feb 2016
Mellor F Breen A Thomas P Thompson P
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Purpose and Background:

To compare static and dynamic lumbar intervertebral ranges of motion (IV-RoM) in patients with chronic, nonspecific low back pain with upper and lower cut off values derived from healthy controls when variability and measurement errors were reduced.

Measurements from functional radiographs suffer from high variability and measurement errors, making cut off values for excessive or insufficient motion problematical. This study compared maximum lumbar IV-RoM and maximum IV-RoM at any point in continuous motion sequences in patients with chronic, non-specific back pain with upper and lower cut off values for L2 to L5 from matched controls using quantitative fluoroscopy, where variation and measurement errors were reduced.

Methods and Results:

Participants underwent passive recumbent examinations in the sagittal and coronal planes. Values based on were developed for both maximum and continuous motion in controls (n=40). Fishers exact test was used to analyse proportions of patients whose IV-RoMs exceeded reference values.

For maximum IV-RoM in patients, there were no statistically significant differences between groups for the lower value. Only flexion at L4/5 significantly exceeded the upper value (p=0.03). For continuous IV-RoM, left L3/4 (p=0.01) and right L4/5 (p=0.01) were significantly below the lower cut off values. Both flexion L4/5 (p=0.05) and left L3/4 (p=0.01) were significantly above the upper cut off values.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 106 - 106
1 Feb 2012
Ennis O Mahmood A Maheshwari R Moorcroft I Thomas P
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A single centre, prospective study of 196 closed tibial diaphyseal fractures treated by monolateral external fixation. Surgical management of all patients followed a protocol of the senior author (PBMT), with regard to technique and fracture reduction. Operations were performed by several different surgeons including the senior author. A definitive fixator was used as a reduction tool in 34 cases, and a separate fracture reduction device was used in 162 patients. Follow-up was in a dedicated external fixator clinic by the senior author until one year post-fracture healing. Fracture healing was determined by fracture stiffness measurements. 196 tibial fractures in 196 patients, average age 29 (range 12-80). 111 right sided and 85 left sided. 166 male and 30 female. 116 fractures due to low energy and 80 due to high energy.

Mechanism of injury

football 75, fall 52, RTA 49, others 20. 33 patients had an additional 74 injuries: 38 fractures/dislocations (3 open), 7 compartment syndromes, 7 head injuries, 16 chest injuries, 9 soft tissue injuries. According to AO classification system: 33 A1, 47 A2, 42 A3, 15 B1, 46 B2, 7 B3. Time to fracture healing was 19 weeks on average (range 9-87). 15 patients had coronal deformity >5 degrees and 1 also had saggital deformity >10 degrees. One osteotomy for correction of malunion. 279 pin site infections requiring antibiotics in 35 patients. 7 fixators removed early due to pin site infection. One established osteomyelitis-lautenbach. 7 refractures, all healed (5 with pop, 2 with further fixator). Non-union: 5 hypertrophic, 2 atrophic-all healed with further external fixation. Our results show that external fixation of closed tibial fracture is a viable alternative to other treatment methods with regard to healing time and angular deformity.

Our study also uses a well validated end point to define fracture healing and does not rely on the difficulty of defining union on clinical and radiological grounds.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 66 - 67
1 Jan 2011
Kwon Y Thomas P Summer B McLardy-Smith P Ostlere S Gundle R Whitwell D Gibbons C Athanasou N Gill H Murray D
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Introduction: Symptomatic abnormal soft-tissue masses relating to the hip joint, such as those described as pseudotumours, are being increasingly reported following metal-on-metal hip resurfacing arthroplasty (MoMHRA). These were found to be locally destructive, requiring revision surgery in a high proportion (75%) of patients. Lymphocyte infiltrations seen in pseudotumours were similar to aseptic lymphocyte vascular associated lesion (ALVAL), which is thought to represent a T-lymphocyte-mediated delayed type hypersensitivity. Therefore, a delayed hypersensitivity reaction to nickel (Ni), chromium (Cr) or cobalt (Co) has been suggested to play a role in pseudotumour aetiology. In patients with bilateral MoMHRA who presented with symptoms on one side, subsequent scans have demonstrated pseudotumours both on the symptomatic and asymptomatic side. Thus, there are concerns that there may be an appreciable number of asymptomatic pseudotumours that surgeons are unaware of and these may eventually become symptomatic.

Aim: The aims of this study were:

to determine the prevalence of asymptomatic pseudotumours after MoMHRA; and

to measure Co and Cr ion levels as well as lymphocyte proliferation responses to Ni, Co and Cr (the principal elements in the CoCr alloy used in MoMHRA) in MoMHRA patients with and without asymptomatic pseudotumours.

Methods: A total of 201 MoMHRA implanted hips in 158 patients (97 male, 61 female) with a mean age of 56 years (range 33–73 years) were evaluated. The mean follow-up was 61 months (range 13–88 months). Resurfacing devices implanted included 128 Birmingham Hip Resurfacing, 66 Conserve Plus and seven ReCap. The control groups included additional 20 patients, 10 male and 10 female (a mean age 68 years, range 57–80 years) with metal-on-polyethylene total hip arthroplasty and a further 22 age-matched patients (a mean age 55 years) without any metal implants. Ultrasound was used as the initial imaging modality and MRI was used to assess the extent of the identified masses. Patients with a soft-tissue mass had ultrasound-guided aspiration or core biopsy performed. Venous blood samples were collected in all patients for serum cobalt and chromium ion levels analysis using Inductively-Coupled Plasma Mass Spectrometer and lymphocyte transformation tests (LTT). The Oxford Hip Score (OHS) was used to measure the functional outcomes of patients. Acetabular component abduction angle was measured from standardised anteroposterior pelvis radiographs.

Results: Prevalence – Pseudotumours were found in 7 patients (6 female and 1 male). The overall prevalence of asymptomatic pseudotumours was 4%, with a relatively very high (30%) prevalence in females with bilateral implants. Histological examinations showed extensive necrosis of connective tissue, in which there were scattered aggregates of metal particles and a diffuse lymphocyte infiltrate.

Metal Ion Levels – The presence of pseudotumour was associated with significantly higher median serum cobalt levels (9.2mg/L vs. 1.9mg/L, p< 0.001), chromium levels (12.0mg/L vs. 2.1mg/L, p< 0.001), hip aspirate cobalt levels (1182 mg/L vs. 86.2mg/L, p=0.003), and aspirate chromium levels (883mg/L vs. 114.8mg/ L, p=0.006), as well as with inferior functional scores (OHS 41 vs. 47 p< 0.001). There was no significant difference in acetabular cup inclination angle (p=0.51). Lymphocyte Reactivity: A higher incidence and level of enhanced lymphocyte reactivity to Ni (p=0.001), but not to Co or Cr (the principal elements in the CoCr alloy used in metal-on-metal hip resurfacing implants), was found in patients with MoMHRA compared to the patients without MoM implants. However, lymphocyte reactivity to Co, Cr and Ni did not significantly differ in patients with pseudotumours compared to those patients without pseudotumours.

Conclusion: The prevalence of asymptomatic pseudotumours in females was high, especially in females with bilateral MoMHRA implants (30%). The patients with ‘asymptomatic’ pseudotumours were in fact mildly symptomatic. Lymphocyte reactivity to Co, Cr and Ni did not differ in patients with pseudotumour compared to those patients without pseudotumours, suggesting that systemic hypersensitivity type IV reactions, mediated by lymphocyte reactivity to these metals, is not the dominant mechanism in pathogenesis of the soft tissue pseudotumours. Furthermore, pseudotumours were not detected in those patients who had normal levels of cobalt and chromium ions. This suggests that pseudotumours do not occur if MoM articulations are well functioning. Therefore, pseudotumours are likely to be a biological consequence of the large amount of metal debris generated in vivo due to excessive wear.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 546 - 547
1 Oct 2010
Ennis O Clewer G Moorcroft I Ogrodnik P Thomas P
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In a novel external fixation system for tibial fractures accurate reduction is achieved with a complex temporary device (Staffordshire Orthopaedic Reduction Machine: STORM) following which the reduced fracture is fixed using a simple titanium bar fixator (IOS). With the fracture reduced, the external fixator screws may be placed in the optimum position. The fixator is designed to allow controlled bending to optimise movement at the fracture site for callus growth. With no need for adjustable elements, the fixator is small and short enough for epicentric placement in the commonest fracture of the middle and distal thirds. Optimum mechanical properties are approached: elastic return is to the reduced position; epicentric placement minimises shear and distraction on weightbearing. Integral healing assessment measures bending stiffness. The device is single-use.

In 40 tibial fractures (closed or grade I compound) the mean healing time was 15 weeks with a healing endpoint of bending stiffness of 15Nm/deg in two orthogonal axes and full weightbearing on fixator removal with no subsequent creep or refracture. Good reduction, defined as less than 5 deg of maximum angulation and less than 3mm of maximum translation, was achieved and maintained. The incidence of pin site complications was extremely low and there were no deep infections.

This new device thus far has had few of the drawbacks commonly associated with external fixation. The infection rate is low, healing time is comparable to other methods and there have been no malunions. We feel our strict adherence to fracture reduction and pin site hygiene are the most important factors in producing these excellent results.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 523 - 523
1 Oct 2010
Kwon Y Gill H Mclardy-Smith P Monk P Murray D Ostlere S Summer B Thomas P
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Recently, a series of locally destructive soft tissue pseudotumour has been reported in patients following metal-on-metal hip resurfacing arthroplasty (MoMHRA), requiring revision surgery in a high percentage of patients. Based on the histological evidence of lymphocytic infiltration, a delayed hypersensitivity reaction to nickel (Ni), chromium (Cr) or cobalt (Co) has been suggested to play a role in its aetiology. The aim of this study was to investigate the incidence and level of hypersensitivity reaction to metals in patients with pseudotumour.

Materials and Methods: 25 patients were investigated in this Ethics approved study:

Group 1: MoMHRA patients with pseudotumours, detected on the ultrasound and confirmed with MRI (n=6, 5 F:1 M, mean age 53 years);

Group 2: MoMHRA patients without pseudotumours (n=13, 7 F:6 M, mean age 55 years); and

Group 3: age-matched control subjects without metal implants (n=6, 4 F:2 M, mean age 54 years).

Lymphocyte transformation tests (LTT) were used to measure lymphocyte proliferation responses to metals. Peripheral blood mononuclear cells were isolated from heparinized blood samples using standard Ficoll–Hypaque® (Pharmacia). The PBMC were cultured at a cell density of 106 cells/mL. Culture was set up in the presence of either:

medium alone;

nickel chloride (Sigma; 10-4M-10-6M);

cobalt chloride (10-4M-10-6M); and

chromium chloride (10-4M-10-6M).

After 5 days of culture, cells were pulsed with [3H]-thymidine and proliferation was assessed by scintillation counting. The stimulation index (SI) was calculated by the ratio of mean counts per minute of stimulated to unstimulated cultures. A SI value of greater than 2.0 was interpreted as a positive result.

Results: A clinical history of metal allergy was reported in 2/6 in Group 1, 2/13 in Group 2, and none in Group 3. In pseudotumour group, the incidence of reactivity to Ni, Co and Cr was 60%, 17% and 0%, respectively. Within Group 2, the reactivity to Ni, Co and Cr was 69%, 8% and 15%, respectively. One control subject had reactivity to Ni. Inter-group comparisons of mean SI values (Kruskal-Wallis non-parametric analysis of variance) showed no significant differences (p> 0.05).

Discussion: The incidence of enhanced lymphocyte response to metals in patients with MoMHRA was more common than the control group. However, in comparison with non-pseudotumour patients, there was no significant difference in the incidence or the level of lymphocyte reactivity in patients with pseudotumour. We conclude that patients with MoMHRA have an enhanced lymphocyte response to metal ions, reflecting exposure and immune reactivity. However, patients with pseudotumours have a similar proliferative response to those without pseudotumours, which suggests that type IV hypersensitivity may not be the cause of the pseudotumours.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 547 - 547
1 Oct 2010
Ennis O Balain B Clewer G Moorcroft I Ogrodnik P Thomas P
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Introduction: We present a prospective comparative study of 200 consecutive patients of closed tibial shaft fractures treated by external fixation using two different fracture reduction methods. Factors affecting fracture healing, including the effect of quality of reduction, was studied.

Methods: The healing time for all these fractures was determined by a combination of clinical, radiological and fracture stiffness measurements. The effect of smoking, AO classification type, associated fractures, initial and final angulation and translation on healing time was evaluated using nonparametric tests and regression analysis.

Results: Healing time was affected most by presence of Compartment syndrome followed by smoking status and final translation at fracture site. Having a compartment syndrome significantly increased fracture healing time (mean 286.7 days versus 139.2 days). There was no difference in healing times between the two different reduction machines. Angulation was found not to affect healing time, but translation did. Both initial and final translation were better using STORM (Staffordshire Orthopaedic Reduction Machine). The amount of axial shortening was also reduced by using STORM.

Conclusion: Healing time is affected by translation at fracture site, which is a factor under the control of the surgeon. The second reduction method using STORM, helps achieve better reduction.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 403 - 403
1 Jul 2010
Thomas P Ennis O Wagner W Moorcroft C Ogrodnik P
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Introduction: The Staffordshire Orthopaedic Reduction Machine (STORM) was developed to assist in the reduction of tibial shaft fractures prior to the application of an external fixator. Its use has now been extended to fractures of the tibial plateau and plafond, where it has been utilised to gain and hold a good reduction prior to the application of various internal and external fixation techniques.

Methods: The STORM was used sterile within the operative field on a standard radiolucent operating table. It was applied with two tensioned 2 mm wires: the distal through the calcaneum; the proximal through the proximal tibia for shaft and pilon fractures, and through the distal femur for plateau fractures.

Controlled traction was applied through these two wires. Torsion was independently corrected and locked. Translation and angulation was corrected using two translation arms each applied to the tibia with a single unicortical screw. The STORM was removed at the end of each operation.

Results: The STORM was used in 241 cases.

Pilon (n=42): bridging hinge 23 (t [mean operation time in minutes]=102.9), percutaneous plate 10 (t=131.4), ring fixator 5 (t=140), screws and fibula plate 3 (t=77), other 2.

Plateau (n=23): ring fixator 11 (t=129.7), LISS plate 8 (t=98.6 mins), monolateral Garches fixator 3 (t=64.4), screws only 1 (t=15).

Shaft (n=176): monolateral fixator 138 (t=69.1), ring fixator 37 (t=131.2), nail 1 (t=65).

Ilizarov rings up to 200 mm were accommodated.

Discussion: The STORM is a safe device for reliable reduction of tibial plateau, shaft and pilon fractures which allows good access for internal or external fixation. No significant complications attributable to the use of the current design of the STORM were encountered.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 402 - 403
1 Jul 2010
Thomas P Ennis O Wagner W Moorcroft C Ogrodnik P
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Introduction: In a new external fixation system for tibial fractures, accurate reduction was achieved with a complex temporary device, the Staffordshire Orthopaedic Reduction Machine (STORM) following which the fracture was fixed using a simple titanium bar fixator (IOS). The fixator was designed to allow controlled bending to optimise movement at the fracture site for callus growth. Ideal mechanical properties are approached: elastic return is to the reduced position; epicentric placement minimises shear and distraction on weightbearing. Integral healing assessment measures bending stiffness. The device is single-use.

Methods: Closed or grade I compound unstable tibial shaft fractures in 38 patients were externally fixed using the STORM in the operating theatre to reduce the fracture prior to application of an IOS fixator. Immediate full weight-bearing was encouraged. Bending characteristics of the fixator allowed 1 mm of axial movement for 20 kg loading. Fixator removal time was determined by fracture stiffness measurements against which the integral IOS stiffness measurement was compared.

Results: Mean healing time was 18.1 weeks, shortest time 9.5 weeks. The healing endpoint was fixator removal at a bending stiffness of 15 Nm/deg in two orthogonal axes. There was no subsequent creep or re-fracture. Good reduction, defined as less than 3 deg of maximum angulation and less than 3 mm of maximum translation, was achieved and maintained.

Discussion: The IOS/STORM system allows safe and effective treatment of tibial shaft fractures. With the fracture reduced, the external fixator screws can be placed in optimum positions. Good reductions were achieved and maintained. The IOS bending characteristics appear to approach the optimum for callus growth. The simple integral fracture stiffness measurement method has been validated against more complex devices.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 480 - 480
1 Sep 2009
Thomas P Sattar T Nagaria J Bolger C
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INTRODUCTION: Atlanto-axial instability due to Rheumatoid arthritis has been treated by posterior C1/C2 wiring techniques supplemented with bone graft. Magerls technique of Transarticular fixation provides a three-point fixation by eliminating motion, promoting fusion, increased mechanical strength and treating instability. It allows fixation across the plane of movement and prevents basilar invagination.

The clinical results of transarticular fixation are satisfactory in terms of clinical outcome with few complications. However there are concerns that these patients develop subaxial kyphosis. It is important to highlight that none of these patients in our series had supplementary wiring techniques with TAS The purpose of this study is to analyse postoperative Xrays of patients who have undergone transarticular atlantoaxial fixation and look at the following parameters;

What percentage of patients develop subaxial kyphosis?

Are the ADI and PADI maintained postoperatively?

Is there a late failure rate of TAS despite the absence of supplementary wiring techniques?

MATERIALS & METHODS: 15 patients underwent pre and postoperative cervical spine X-rays in the AP and lateral projections. In addition flexion/extension views were also obtained pre and postoperatively.

We analysed the following parmeters:

Pre and Postoperative ADI and PADI.

C0/C1, C1/C2, C1/C7, C2/C7 angles

C2/C3 slip and C2/C3 osteoarthritis

Any breakage or pullout of screws.

Postoperative basilar invagination.

It is important to highlight that all these 15 patients had bony fusion at the C1/C2 joints and these findings have been analysed and published in the clinical counterpart of this study (Fusion rates 97% in 36/37 patients).

RESULTS: As highlighted, the clinical outcome of these patients has been published. We would like to present the radiological parameters of this subgroup of patients. The ADI improved in 13 patients with a preoperative median of 7 and postoperatively 3.5. The preoperative and postoperative PADI remained at 15. The C0/C1 angle changed from 12 to 17 postoperatively. The C2/C7 angle changed from 21 to 26 postoperatively. C1/C7 angle changed from 39 to 41. The spinal cord diameter remained at 15 pre and postoperatively.

There was only 1 patient with C2/C3 slip on flexion/extension views. 2 patients developed subaxial kyphosis with evidence of significant disc degeneration on preoperative imaging.

There are some interesting conclusions from these 15 xrays.

Only 2 out of 13 patients have developed a subaxial kyphosis.

The 2 patients that have developed subaxial kyphois had subaxial disc degeneration at the level of the kyphois

There was only 1 patient with a C2/C3 spondylolisthesis on flexion/extension.

The ADI and SAC were maintained at the craniocervical junction.

There is no late failure rate despite the absence of a modified gallie fusion


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 78 - 78
1 Mar 2009
Mahmood A Ennis O Maheswari R Moorcroft I Thomas P
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Single centre prospective study of 196 closed tibial diaphyseal fractures treated by monolateral external fixation.

Methods: Surgical management of all patients followed protocol of senior author (PBMT), with regard to technique and fracture reduction.

Operations performed by several different surgeons including senior author.

Definitive fixator used as a reduction tool in 34 cases, fracture reduction device used in 162 patients – ST.O.R.M

Followed up in a dedicated external fixator clinic by the senior author until one year post fracture healing.

Fracture healing was determined by fracture stiffness measurements.

Results: 196 tibial fractures in 196 patients, average age 29 (range 12–80).

111 right sided and 85 left sided.

166 male and 30 female.

116 fractures due to low energy and 80 due to high energy.

Mechanism of injury: football 75, fall 52, RTA 49, direct blow 7, assault 4, rugby 3, crush 2, dancing 2, bowling 1, roller skating 1.

33 patients had an additional 74 injuries: 35 fractures (3 open), 7 compartment syndromes, 3 dislocations, 7 head injuries, 16 chest injuries, 9 soft tissue injuries.

According to AO classification system: 33 A1, 47 A2, 42 A3, 15 B1, 46 B2, 7 B3.

Time to # healing was 19 weeks on average (range 9–87)

X ray data: 15 patients had deformity > 5 degrees in the coronal plane and 1 of these also had deformity > 10 degrees in the saggital plane.

One patient underwent osteotomy for correction of malunion.

85 patients had a total of 279 pin site infections requiring Abx (6 with 14 pin infections requiring iv abx), and 33 pins were removed due to persistent infection. 15 patients had 32 ring sequestra which settled with debridement under GA.

7 fixators removed early due to pin site infection.

1 established osteomyelitis-lautenbach.

7 refractures, all healed(5 with pop, 2 with further fixator)

Non-union: 5 hypertrophic, 2 atrophic-all healed with further external fixation.

Malunion: 1

Conclusion: Our results show that external fixation of closed tibial fractures is a viable alternative to other treatment methods with regard to healing time and angular deformity.

Our study also uses a well validated end point to define fracture healing and does not rely on the difficulty of defining healing on clinical or radiological grounds which is known to be unreliable. This is the first time this highly repeatable methodology has been used for such fractures.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 465 - 465
1 Aug 2008
Moorcroft C Thomas P Ogrodnik P
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This is a clinically based study to assess the reliability of fracture stiffness as a measurement of clinical union and investigate other indicators which may aid the clinician to accurately determine when fracture fixation may be removed.

A fracture bending stiffness in the sagittal plane of 15Nm/deg. has been stated as a satisfactory endpoint at which an external fixator may be removed from diaphyseal fractures of the tibia. However using this as a measure to determine when to remove support in a study of 76 patients 4 continued to a malunion. Fracture callus properties were measured in clinic. The fixator was removed for the tests and a specially designed system was used to measure displacement and load. Fracture stiffness was measured in different planes and at various loading rates. Passive stressing of the leg was performed whilst fracture displacement was recorded. A constant load was applied for a longer period to assess creep properties.

Fracture stiffness was found to vary between different planes of measurement and on load rate. The visco-elastic characteristics of the callus changed with time. In early measurements, the callus absorbed a large proportion of energy when a load was applied. Later tests showed a progressive change with the callus absorbing less energy. This demonstrates that the properties of the callus changed with time, with the viscous element diminishing and the elastic element increasing. This sometimes occurred with no change in the measured fracture stiffness.

Further investigation is needed, focusing on the visco-elastic properties of callus, to develop a more reliable method of determining clinical union.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 469 - 469
1 Aug 2008
Ennis O Mahmood A Maheshwari R Moorcroft I Thomas P
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A prospective study of 196 closed tibial diaphyseal fractures treated by a monolateral external fixator is presented.

The patients were managed by a group of Surgeons including the senior author (PBMT), a definitive fixator being used in 34 patients, and a fracture reduction device in 162 patients. All the patients were followed up in an external fixator clinic by the senior author, and follow up continued for 1 year after the fractures had healed. Fracture healing was determined clinically.

There were 196 tibial fractures, with an average age of 29 years (range 12–80 years). 111 Fractures involved the right tibia, and 85 the left. There were 166 males and 30 females. 116 Fractures were deemed due to a low energy accident, and 80 due to a high energy injury. The most common mechanism of injury was football (75), a fall (52), a road vehicle accident (49), direct trauma (7), assault (4), and rugby (3). According to the AO classification system 33 were A1 fractures, 47 A2, 42 A3, 15 B1, 46 B2, and 7 B3. Time to fracture healing was 19 weeks on average (with a range from 9–87 weeks).

15 Fractures united with a deformity of more than 50 in the coronal plane. One patient required a corrective osteotomy for a mal-united fracture. There were 279 pin track infections that required antibiotic treatment in 85 patients. 33 Pins had to be removed due to persistent infection. Of these patients 15 developed 32 ring sequestrae, but infection was settled by debridement under GA. 7 External fixators had to be removed early because of pin site infection. One patient developed a full blown osteomyelitis, which was treated with the Lautenbach irrigation and settled. There were 7 re-fractures, but all healed after further treatment. 5 Were treated in a POP cast and 2 were re-treated with another external fixator. There were 7 non-unions, but all eventually healed with further treatment with an external fixator.

The authors conclude that treating a closed tibial fracture with an external fixator is a viable alternative method of treatment.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 211 - 211
1 Mar 2004
Thomas P
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Apart from the inflammatory reaction upon surgery itself, the immunological biocompatibility of a given material varies with factors like the site of implantation, the immunogenicity of implant constituents and the individual reactivity of the patient. Most investigations have focused on cytotoxic, osteolytic or proinflammatory effects of wear debris and corrosion products. In some patients specific immune response, e.g. allergic reactions, to the implant components may develop and lead to localized or generalized eczema, local swelling, recurrent urticaria or even implant loosening. However the number of these patients seems to be much lower than the sensitisation rates to cobalt, chromium or nickel ranging between 2–10% in the general population. To identify implant associated allergic reactions the diagnostic approach should encompass both epicutaneous patch testing and in vitro methods, e.g. analysis of T-cell reactivity in peripheral blood and perimplantar tissue. Several patients with allergy-mediated implant intolerance under the picture of eczema, swelling, seroma formation or implant loosening will be presented. Based on these cases, a new panel of patch test substances (developed by the German Contact Dermatitis Group), immunohistology and molecular biology approach to characterize the periimplantar immune response will be exemplified. As the author is actually establishing a nationwide register for implant-associated allergic reactions, more information about incidence and clinical picture of these reactions will be available in the future. Certainly, these patients profit from an interdisciplinary problem solving approach.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 176 - 176
1 Feb 2003
Narvani A Chaundhuri R Tsiridis E Thomas P
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To the best of our knowledge, this prospective study is the first to investigate the prevalence of acetabular labrum tears in athletes presenting with groin pain.

Eighteen consecutive athletes who presented to our sports clinic with groin pain, underwent Magnetic Resonance Arthrography (MRA). Presence or absence of acetabular labrum tears, were reported on by a Consultant Radiologist, who has an interest in musculoskeletal radiology.

In 4 out of 18 athletes with groin pain (22.2%), the Magnetic Resonance Arthrography demonstrated the presence of acetabular labrum tear. Two underwent hip arthroscopy and treatment

Acetabular labrum tears can be a common cause of groin pain in athletes. Sports clinicians have to be well aware of the condition. Magnetic resonance arthrography of the hip can be a valuable tool in diagnosing this pathology.


The Journal of Bone & Joint Surgery British Volume
Vol. 78-B, Issue 4 | Pages 683 - 683
1 Jul 1996
ROBERTS S THOMAS P


The Journal of Bone & Joint Surgery British Volume
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