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Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_9 | Pages 49 - 49
1 May 2017
Fox N Stanley M Thomas D Fisher J Ingham E
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The ability to pre-clinically evaluate new cartilage substitution therapies in viable physiological biotribological models, such as the femoral-tibial joint would be advantageous. Methods for osteochondral (OC) plug culture have been developed and the aim of this study was to extend these methods to organ culture of whole femoral condylar and tibial osteochondral tissues.

Porcine femoral condyles and tibial plateau were aseptically dissected. The majority of cancellous bone was removed leaving intact cartilage and a layer of cortical bone. OC plugs were from porcine knee condyles. “Whole joint” tissues and OC plugs were cultured in defined medium and the viability of the cartilage at day 0, 8 or 14 days of culture assessed by XTT assay and LIVE/DEAD staining. Histological analysis (H&E; alcian blue staining) was used to determine cell number and visualise glycosominoglycans (GAGs). GAG levels were quantified in the cartilage using the dimethylene blue assay.

XTT conversion by OC plug cartilage reduced significantly between day 0 and day 8 with no further change between day 8 and 14. GAG levels did not change. “Whole joint” tissue behaved similarly with reduced XTT conversion between days 0 and 8 (femoral only) and days 0 and 14 (femoral and tibial). LIVE/DEAD staining showed the majority of cells remained alive in the mid and deep cartilage zones. There was a band of mainly dead cells in the surface zone, from day 0. There was no change in the GAG levels over the 14 day culture period.

In conclusion, large cuts of femoral and tibial osteochondral tissues were maintained in organ culture for extended periods. Surface zone chondrocytes rapidly lost membrane integrity ex-vivo whereas mid- and deep zone chondrocytes remained viable. It is hypothesised that physiological loading in a novel physically interactive bioreactor will improve the viability and will be the focus of future studies.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_18 | Pages 9 - 9
1 Dec 2014
Aranganathan S Carpenter C Thomas D Hemmadi S O'Doherty D
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Complex congenital foot deformities pose a challenge to the surgeon due to poor results after extensive surgery. We report the clinical outcomes of children with complex congenital foot deformities treated with UMEX® (Universal mini-external fixator System) frames.

This is a prospective review of our experience in patients treated in this way, from 2004 to 2011. The indications for treatment included resistant/recurrent Congenital Talipes Equino Varus (CTEV), cavo-varus deformity secondary to Charcot-Marie-Tooth disease, arthrogryposis, fibular hemimelia and other congenital abnormalities. A total of 32 children (35 feet) have been treated, out of which 22 were male and 10 were female patients. Age at surgery ranged from 3 to 15 years (median age – 7 years). Three patients underwent bilateral procedures; the reminder (29 patients) underwent unilateral foot operations. Twenty-eight patients had undergone previous surgery including soft-tissue and/or bony corrective procedures.

The frames were removed at an average of 69 days after application, and the patients spent a further 6 weeks in a walking cast. Good functional outcomes were noted in 26 patients in the first postoperative year and in 19 patients in the fifth postoperative year. Further operations were needed in 10 patients. Complications occurred in 10 patients, predominantly pin-site infections and 1 case of bony overgrowth at pin-site and 1 of proximal tibio-fibular diastasis.

This is a simple fixator to use with a short learning curve. In groups of patients with complex congenital abnormalities, we achieved good functional outcome with low-complication rates.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 191 - 191
1 Jul 2014
Sladkova M Manassero M Myrtil V Savari H Fall M Thomas D Bensidhoum M Logeart-Avramoglou D Petite H
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Introduction

The use of mesenchymal stem cells (MSCs) loaded on osteoconductive scaffolds has emerged as a potential new treatment of large bone defects but has generated marginally successful results in terms of new bone formation. It is supposed that MSC massive death post implantation is a major obstacle for the exhibition of their osteogenic potential. Yet, the very few studies conducted using primary human MSCs derived from bone marrow (hMSCs), a clinically pertinent cell source, did not demonstrate that cell survival is required for new bone formation. In order to elucidate whether cell survival is needed for hMSC to express their osteogenic potential, the present study examined in an ectopic mouse model the relationship between cell survival and osteogenic potential of hMSCs loaded onto osteoconductive scaffold.

Materials and Methods

hMSCs (106) were seeded on 40-mg calcium carbonate (Biocoral) particles (size: 610–1000 µm), wrapped in fibrin gel (Baxter), and implanted subcutaneously into immunodeficient (nu/nu) mice (n=8/group). The fate of implanted cells was analysed using the bioluminescence and immunohistochemistry. For this, hMSCs were transduced with Luc-GFP (Luciferase-Green fluorescent protein) lentiviral vectors prior to experimentation. Bone formation was analysed 8 weeks post implantation on both non-decalcified and decalcified samples.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 301 - 301
1 Mar 2013
Patel A Patel R Thomas D Stulberg SD Bauer T
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Introduction

Modular femoral necks have shown promising clinical results in total hip arthroplasty (THA) to optimize offset, rotation, and leg length. Given the wide variety of proximal femoral morphology, fine-tuning these kinematic parameters can help decrease femoroacetabular impingement, decrease wear rates and help prevent dislocations. Yet, additional implant junctions introduce additional mechanisms of failure. We present two patients who developed an abnormal soft tissue reaction consistent with a metal hypersensitivity reaction at a modular femoral neck/stem junction requiring revision arthroplasty.

Methods

Two patients underwent THA for primary osteoarthritis with the same series of components: 50 mm shell, a 36 mm highly-crosslinked polyethylene liner, uncemented titanium alloy modular stem with a 130 degree Cobalt Chromium (CoCr) modular femoral neck, and 36 mm CoCr head with a +5-mm offset. Patient 1 was a 63 year-old female who had an uneventful post-operative course but presented seven months later with progressive pain in the left hip. Patient 2 was an 80 year-old female who did well post-operatively, but presented with limp and persistent pain at 10 months post-op.

An initial evaluation of a painful THA to rule out aseptic loosening, infection, mal-positioning, loosening and osteolysis included radiographs, lab work (CBC, ESR, CRP, Cobalt & Chromium levels) and Metal Artifact Reduction Sequence (MARS) MRI.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_9 | Pages 16 - 16
1 Feb 2013
Aranganathan S Carpenter C Thomas D Hemmadi S O'Doherty D
Full Access

We report the clinical outcomes of children with complex congenital foot deformities treated with UMEX® mini-external fixators. This is a prospective review of our experience in patients treated in this way, from 2004. The indications for treatment were resistant/recurrent Congenital Talus Equina Varus(CTEV), cavo-varus deformity secondary to Charcot-Marie-Tooth disease, arthrogryposis, fibular hemimelia and other congenital abnormalities. In addition, one patient underwent this treatment since he was allergic to casting material.

A total of 32 children (35 feet) have been treated, with a male to female ratio of 22:10 respectively. The patient-age at operation ranged between 3 and 15 years (median age −7 years). Three patients underwent bilateral procedures and 29 patients underwent unilateral foot operations. Twenty-eight patients underwent previous soft-tissue and bony corrective operations with serial casting. The frames were removed at an average of 69 days after application with a further 6 weeks in a walking cast. Seventy-nine percent of the patients had good functional outcome. Further operations were needed in 10 patients. Complications occurred in 10 patients, including pin-site infections, bony overgrowth at pin-site and proximal tibio-fibular diastasis.

In conclusion, this is a simple fixator to use with a small learning curve. In groups of patients with complex congenital abnormalities, we achieved good functional outcome with low-complication rates.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 372 - 372
1 Sep 2005
Carpenter C Thomas D Hemmadi S O’Doberty D
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We report our initial experience with the Universal Mini External Fixator (UMEX) frame for the treatment of complex congenital foot deformities. This new frame is simple to apply and manage. It provides for multiplanar deformity correction in one stage.

The application of external fixators for the correction of foot deformities can be a complex procedure for the surgeon and cumbersome for the patient. Currently, five patients (mean age 10 years, range 4–18) have undergone application of this frame and have completed treatment. We illustrate the ease of its application, potential complications and the early clinical outcomes.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 12 - 12
1 Mar 2005
Thomas D Sanchez P Hoffman E
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This is an ongoing retrospective study of 35 children treated from 1986 to 2001 for chronic osteomyelitis following acute haematogenous osteomyelitis. The purpose was to validate the use of a modified Cierny classification to predict behaviour, to assess the timing of sequestrectomy in relation to involucrum formation, and to evaluate the results of dealing with the resultant defect by conventional methods of bone grafting.

The mean age of the patients was 7 years (1 to 12). All except 18, who were treated within five days of acute onset, were delayed presentations or transfers. In 14 children the tibia was involved, in 13 the femur, in five the humerus and in three the fibula. Monthly radiographs were taken and the size and location of the sequestrum and involucrum was documented.

Our classification represents the size and location of the sequestrum. We divided the patients into cortical (one), medullary (three), corticomedullary (12) and structural (19) types. Fractures occurred in all the structural types, as well as in five of the 12 corticomedullary types. A sequestrum was apparent at a mean of 2.4 months (1 to 3). The mean length of the sequestrum at diagnosis was 8.5 cm and at surgery 5.8 cm, suggesting partial resorption. Involucrum formed in 69% of patients at a mean of 1.9 months (1 to 3) after sequestrum. In 31% of patients no involucrum formed from 4 to 12 months after surgery. This suggests that involucrum formation depends on viable periosteum and not on the sequestrum, and in the absence of involucrum early rather than late sequestrectomy is warranted.

The resultant incomplete bone defects in the corticomedullary type ranged from 1 cm to 15 cm, but had an intact cortical bed on one or more sides. These and complete defects of less than 6 cm in the structural type united after autogenous cancellous bone grafting, with or without an exoskeleton. Four structural defects greater than 6 cm united after fibular strut grafting (humerus) or bone grafting from fibula to tibia via a posterolateral approach (tibia).

Patients were followed up both clinically and radiologically for a mean of 2.9 years. Twenty patients (57%) had an excellent result and 15 (43%) a good result.


The Journal of Bone & Joint Surgery British Volume
Vol. 70-B, Issue 3 | Pages 431 - 434
1 May 1988
Dodd C Fergusson C Freedman L Houghton G Thomas D

The results of a study of the use of autograft versus allograft bone in the surgery of idiopathic adolescent scoliosis are presented. Two groups of patients, matched for age, sex, level and angle of curve, received bone grafts, 20 patients having autogenous bone from the iliac crest and the other 20 having donor bone from a bone bank. Both groups had otherwise identical posterior fusions and Harrington instrumentation. There was no difference between the two groups in a blind, radiographic assessment of bone graft mass at six months, nor in maintenance of the curve correction over the same period. No major operative complications nor failures of instrumentation were encountered. There was, however, a marked reduction in operative time and blood loss in the patients receiving donor bone and also a much lower incidence of late symptoms relating to the operative sites. We conclude that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery.


The Journal of Bone & Joint Surgery British Volume
Vol. 68-B, Issue 1 | Pages 42 - 44
1 Jan 1986
Devereaux M Parr G Lachmann S Thomas D Hazleman B

Pain in front of the knee is common in athletes and is often called patellofemoral arthralgia, but it is difficult to prove that the pain arises in that joint. Thermograms of 30 athletes clinically considered to have patellofemoral arthralgia were compared with those of a similar number of unaffected athletes matched for age and sex. A comparison was also made with thermograms of two older groups of 30 patients with knee involvement from either rheumatoid arthritis or osteoarthritis. Twenty-eight of the athletes with patellofemoral arthralgia had a diagnostic pattern on thermography. The anterior knee view showed a rise in temperature on the medial side of the patella and the medialis knee view showed that this temperature rise radiated from the patellar insertion of the vastus medialis into the muscle itself. The possible aetiological role of quadriceps muscle imbalance in athletes with patellofemoral arthralgia is discussed in relation to these findings.


The Journal of Bone & Joint Surgery British Volume
Vol. 66-B, Issue 4 | Pages 513 - 517
1 Aug 1984
Citron N Edgar M Sheehy J Thomas D

Intramedullary spinal cord tumours may present as scoliosis without neurological signs. Those treating spinal deformities should be alert to this possible aetiology. The clinical features of 12 such cases are discussed with reference to early diagnosis and treatment. Patients with a painful scoliosis should be investigated with myelography as well as bone scintigraphy. Many intrinsic spinal cord tumours are now amenable to surgical removal. The prognosis for neurological recovery is poor once a severe deficit becomes established. The importance of early diagnosis and joint orthopaedic and neurosurgical management is emphasised.