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Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_5 | Pages 25 - 25
1 Apr 2018
Mo A Berliner Z Porter D Grossman J Cooper J Hepinstall M Rodriguez J Scuderi G
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INTRO

Two-stage revision arthroplasty for PJI may make use of an antibiotic-loaded cement spacer (ACS), as successful long- term prevention of reinfection have been reported using this technique.[i] However, there is little data on systemic complications of high-dose antibiotic spacers. Acute kidney injury (AKI) is of clinical significance, as the drugs most commonly utilized, vancomycin and aminoglycosides, can be nephrotoxic. We intended to determine the incidence of AKI in patients that underwent staged revision arthroplasty with an ACS, as well as to identify potential predisposing risk factors for the disease.

METHODS

Local databases of six different orthopaedic surgeons were retrospectively reviewed for insertion of either a static or articulating antibiotic cement spacer by from 2007–2017. Dose of antibiotic powder implanted, as well as IV antibiotic used, was collected from operative records. Demographics, comorbidities, and preoperative and postoperative creatinine and hemoglobin values were recorded from the EHR. AKI was defined by a more than 50% rise in serum creatinine from preoperative baseline to at least 1.4 mg/dL, as described by Menge et al.[ii] Variables were analyzed for the primary outcome of AKI within the same hospital stay as insertion of the ACS. Categorical variables were analyzed with Chi-Square test, and continuous variables with univariate logistic regression.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_5 | Pages 90 - 90
1 Mar 2017
Porter D Bas M Cooper J Hepinstall M Rodriguez J
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BACKGROUND

This study aims to identify recent trends in discharge disposition following bilateral total knee arthroplasty (TKA) as well as factors that predispose patients to enter inpatient rehabilitation facilities (IRF) or skilled nursing facilities (SNF) versus home-rehabilitation (HR). The goal was to identify risk factors that predispose prolonged hospital stays and identify changes in management over time that may be responsible for decreased length of stay (LOS) and a HR program.

METHODS

A retrospective cohort study design was used to collect and analyze clinical and demographic data for 404 consecutive bilateral primary total knee arthroplasty (TKA) procedures. Patients who underwent elective primary bilateral total knee arthroplasty from 2011 to 2016 were identified from hospital records at a single institution. Clinical and demographic data including sex, age, and disposition were analyzed


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_5 | Pages 91 - 91
1 Mar 2017
Porter D Grossman J Mo A Scuderi G
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BACKGROUND

High-dose antibiotic cement spacers are commonly used to treat prosthetic joint infections following knee arthroplasties. Several clinical studies have shown a high success rate with antibiotic cement spacers, however there is little data on the systemic complications of high-dose antibiotic spacers, particularly acute kidney injury (AKI). This study aims to determine the incidence of AKI and identify risk factors predisposing patients undergoing staged revision arthroplasty with antibiotic cement spacers.

METHODS

A single-institution, retrospective review was used to collect and analyze clinical and demographic data for patients who underwent staged revision total knee arthroplasty with placement of an antibiotic-impregnated cement spacer from 2006 to 2016. A search was made through specific procedure (DRG) and diagnostic (CD) codes. Baseline descriptive data were collected for all patients including age, sex, medical comorbidities, type and quantity of antibiotics used in the cement spacer, pre- and postoperative hemoglobin (Hg), BMI, smoking status, peak creatinine levels, and random vancomycin levels. Acute kidney injury was defined as a more than 50% rise in serum creatinine from a preoperative baseline within 90 days postoperatively.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_3 | Pages 10 - 10
1 Feb 2014
Hunter L Goudie ST Porter D
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The aim of this study was to produce estimates of specificity and predictive value of presenting symptoms and signs of paediatric bone cancer, a rare and frequently misdiagnosed condition, to aid clinical decision-making in primary care.

A systematic literature review plus questionnaire to primary care physicians were carried out to determine frequency of bone cancer symptoms in both cancer and the benign conditions as which cancer is misdiagnosed. Literature sources – Ovid MEDLINE (1950-May 2008), EMBASE (1980-May 2008) and AMED (Allied and Alternative Medicine) (1985-May 2008). Literature review methods – We included systematic reviews, cohort studies or case series (where n ≥ 10), reporting frequency of symptoms and signs at initial presentation, as originally recorded in case notes or observed by the authors, in subjects aged 0–18 years. Disease incidence data was taken from retrospective and prospective studies from 1980 onwards which recorded incidence over a defined time period, in a large pre-defined population within Europe, North America or Australia. Questionnaire respondents – 32 general practitioners and paediatric Accident & Emergency physicians throughout Scotland and England.

Positive predictive values (PPVs) for bone cancer symptoms range from 0.003 to 0.034% (percentage of children presenting with symptom who have cancer). Specificity (percentage of children without cancer who do not have the symptom) varies considerably between symptoms and ranges from 24% (tenderness) to 95% (weight loss). Specificity can be improved by looking for combinations of symptoms. Weight loss and fever are the features with both highest specificity and highest PPV.

Bone cancer symptoms, even those with high specificity for cancer, have low positive predictive value. We suggest that diagnosis based on initial presentation to primary care is intrinsically difficult and that delay in diagnosis is not unreasonable if it is to make use of time as a diagnostic aid.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 480 - 480
1 Dec 2013
Pienkowski D Porter D Monier-Faugere M Malluche H
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Advances in the performance and longevity of total joint arthroplasty (TJA) have been enabled by related progress in implant materials, device designs, and surgical techniques. Successful TJA also depends upon adequate bone quality to provide an enduring mechanical foundation. Bone quality can be defined as the ability to repetitively withstand physiologically-relevant loads without excess deformation or fracture. It is now recognized that bone quality encompasses more than just material quantity, i.e. densitometrically-measured bone mass. Bone quality is also determined by: material composition and arrangement, cortical and cancellous structure, and extent of microdamage. These properties, together with the appropriate mass, confer bone with the biomechanical competence needed to meet the repetitive load-bearing demands imposed by total joint implants.

The need for TJA continues to increase in the aging global baby-boomer population. Unfortunately, this group is also experiencing increases in related comorbidities including: osteoporosis, kidney dysfunction, and diabetes, among others. Collectively these three comorbidities afflict more than 74 million Americans, and each is increasing at 2–8% annually. More importantly, each of these comorbidities negatively affects bone quality through alterations in bone turnover independent of bone mass changes commonly associated with these diseases. Specifically, alterations in bone turnover result in abnormal mineral-to-matrix ratios as measured by Fourier transform infra-red (FTIR) spectroscopy (Fig. 1) and altered Young's moduli (shape-independent resistance to deformation) as measured by nanoindentation (Fig. 2). These parameters are related to bones' fracture toughness and load-bearing capabilities, respectively. Also, low bone turnover is associated with mechanically important structural changes, i.e., decreased trabecular thickness (Fig. 3), cortical thickness and cancellous volume. Furthermore, low bone turnover may result in reducing the repair rate of physiologically – induced bone microdamage. This may lead to increases in the number or length of bone cracks, crack coalescence, and ultimately reduced energy needed for fracture.

Therefore, patients needing TJA who also have comorbidities associated with abnormal bone quality are at risk for inferior arthroplasty results. Recognition and treatment of the TJA-relevant biomechanical implications of these comorbidities may help improve outcomes.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 483 - 483
1 Dec 2013
Porter D Urban R Jacobs JJ Rodriguez J Cooper J
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There is renewed concern surrounding the potential for corrosion at the modular head-neck junction to cause early failure in modern hip implants. Although taper corrosion involves a complex interplay of many factors, previous studies have correlated decreasing flexural rigidity of the femoral trunnion with an increased likelihood of corrosion at retrieval. A multicenter retrieval analysis of 85 modular femoral stems was performed to calculate the flexural rigidity of various femoral trunnions. Stems were implanted between 1991–2012 and retrieved between 2004–2012. There were 10 different taper designs from 16 manufacturers. Digital calipers were used to measure taper geometries by two independent observers. Mean flexural rigidity was 262 Nm2, however there was a wide range of values among the various stems spanning nearly an order of magnitude between the most flexible (80 Nm2) and most rigid (623 Nm2) trunnions, which was due in part to the taper geometry and in part to the material properties of the base alloy. There was a modest but significant negative correlation between flexural rigidity of the trunnion and release date of the stem. This wide variability in flexural rigidity may predispose particular stem designs to an increased risk of corrosion at the modular head-neck taper, and may in part explain why taper corrosion is being seen with increasing frequency in modern hip arthroplasty.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_25 | Pages 14 - 14
1 May 2013
Clement N Porter D
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There is a high rate of forearm deformity in patients with hereditary multiple exostoses (HME), and a quarter of patients acquire a dislocated radial head due to disproportionate ulnar shortening.

One-hundred and six patients with HME aged 15 years or older were identified from a prospective database. Flexion and extension of the elbow and wrist, and supination and pronation of the forearm was measured. The number of exostoses affecting the proximal and distal radius and ulna were recorded. Proportional ulna length was calculated as a percentage of the patients measured height ([ulna length/height] × 100).

More than 70% of patients were affected by exostoses of the forearm, of which the distal radius was the commonest site to be affected (73%). One in seven patients had a dislocated radial head, which was associated with proportional ulna shortening (p<0.001). Both radial head dislocation (p<0.001) and proportional ulna shortening (p<0.001) were confirmed to be independent predictors of forearm motion on multivariable regression analysis. In conjunction with other predictors these could be used to calculate ROM of the forearm. In addition proportional ulna length was also an independent predictor of radial head dislocation (p<0.001).

Proportional ulna length could be used as a tool to identify patients at risk of diminished forearm motion and radial head dislocation during childhood, who could be monitored clinically and radiographically, and surgical intervention could be offered before deterioration in function and dislocation of the radial head occurs.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_11 | Pages 7 - 7
1 Feb 2013
Singhota J Clement N Hillman S Porter D Robb J
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Aim

In previous small series, some authors have suggested a difference between re-fractures through immature callus and remodelled bone. We aimed to determine whether different fracture patterns occur in early and late re-fractures of paediatric forearm bones.

Methods

Notes and radiographs of 77 forearm re-fractures from children aged 2–14 years were retrieved from our institution's radiographic database. Children treated surgically at initial presentation and re-fractures beyond one year were excluded. A control group of 100 forearm fractures without complication was used for comparison. Statistical analysis used chi-square and unpaired t-tests and statistically significant results were based on a two-tailed p-value <0.05


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 216 - 216
1 Sep 2012
Ahmed I Clement N Tay W Porter D
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Background

Fractures of the scaphoid are uncommon in the paediatric population. Despite their rarity a significant number of children are referred to the fracture clinic for a suspected scaphoid fracture. The aim of this study is to report on the incidence and pattern of injury of the paediatric scaphoid fracture and present a new classification.

Methods

An analysis of all paediatric scaphoid fractures treated in the Royal Hospital for Sick Children, Edinburgh (age up to 14 years old) over a five year period. The case notes, radiographs and were applicable MRI scan for these patients were reviewed. The clinical information recorded included the dominant hand, mechanism of injury, clinical features on examination, type of cast and length of period, stiffness following cast removal and evidence of delayed or non union. Each radiograph was analysed independently and fracture classified according to a new classification system.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 414 - 414
1 Sep 2012
Chaudhury S Holland C Porter D Vollrath F Carr A
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Introduction

The pathophysiology of high failure rates following rotator cuff tendon repairs, particularly massive tears, is not fully understood. Collagen structural changes have been shown to alter tendon thermal and mechanical properties. Thermal changes in small biopsies, detected by differential scanning calorimetry (DSC) can help to quantify collagen structural differences in torn rotator cuff tendons. This study aimed to form a quantitative rather than qualitative assessment, of whether differences in collagen structure and integrity existed between small biopsies of normal, small and massive rotator cuff tears using DSC.

Methods

Thermal properties were measured for 27 human biopsies taken intra-operatively from normal, small, and massive rotator cuff tendon tears. 3 samples were taken from each patient and subjected to a modulated temperature ramp between 20–80°C at a rate of 2°C per minute with 0.318°C amplitude. The melting temperature (TM) is proposed to represent amide-amide hydrogen bond breakage and resulting protein backbone mobility. Denaturing temperature (TD) reportedly corresponds to the temperature at which the proteins fall out of solution. Denaturation enthalpy (H) should correlate with the amount of triple helical structure. Based upon a pre-study power calculation, this study had 90% power to detect a 10% difference in melting and denaturation temperature between groups with alpha=0.05.

1 specimen per patients was also frozen and cryosectioned and polarised light microscopy was used for quantitative validation. The effect of tear size on heat related parameters were performed using a one-way ANOVA test. A student's unpaired t-test was used to search for differences between individual groups (small tears, massive tears and normal tendons).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIII | Pages 1 - 1
1 Jul 2012
Thomson W Porter D Demosthenous N Elton R Reid R Wallace W
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Metastatic osteosarcoma is seen in 10-20% of patients at initial presentation with the lung the most common site of metastasis. Historically, prognosis has been poor. We studied trends in survival in our small developed nation and aimed to identify correlations between the survival rate and three factors: newer chemotherapy, advances in radiological imaging and a more aggressive approach adopted by cardiothoracic surgeons for lung metastases.

Our national bone tumour registry was used to identify patients at the age of 18 or under, who presented with metastatic disease at initial diagnosis between 1933 and 2006. There were 30 patients identified. Kaplan-Meier analysis was used to determine survival rates and univariate analysis was performed using the Cox regression proportional hazards model.

Median survival has improved over the last 50 years; highlighted by the ‘Kotz’ eras demonstrating incremental improvement with more effective chemotherapy agents (p=0.004), and a current 5-year survival of 16%. Aggressive primary and metastatic surgery also show improving trends in survival. Three patients have survived beyond five years. The introduction of computerised tomography scanning has led to an increase in the prevalence of metastases at initial diagnosis.

Metastatic osteosarcoma remains with a very poor prognostic factor, however, aggressive management has been shown to prolong survival.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXVIII | Pages 17 - 17
1 Jun 2012
Thomson W Porter D Demosthenous N Elton R Reid R Wallace W
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Metastatic osteosarcoma is seen in 10-20% of patients at initial presentation with the lung the most common site of metastasis. Historically, prognosis has been poor. We studied trends in survival in our small developed nation and aimed to identify correlations between the survival rate and three factors: newer chemotherapy, advances in radiological imaging and a more aggressive approach adopted by cardiothoracic surgeons for lung metastases.

Our national bone tumour registry was used to identify patients at the age of 18 or under, who presented with metastatic disease at initial diagnosis between 1933 and 2006. There were 30 patients identified. Kaplan-Meier analysis was used to determine survival rates and univariate analysis was performed using the Cox regression proportional hazards model.

Median survival has improved over the last 50 years; highlighted by the ‘Kotz’ eras demonstrating incremental improvement with more effective chemotherapy agents (p=0.004), and a current 5-year survival of 16%. Aggressive primary and metastatic surgery also show improving trends in survival. Three patients have survived beyond 5 years. The introduction of computerised tomography scanning has led to an increase in the prevalence of metastases at initial diagnosis.

Metastatic osteosarcoma remains with a very poor prognostic factor, however, aggressive management has been shown to prolong survival.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 42 - 42
1 May 2012
Chaudhury S Holland C Porter D Vollrath F Carr AJ
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Background

High re-rupture rates following repairs of rotator cuff tears (RCTs) have resulted in the increased use of repair grafts to act as temporary scaffolds to support tendon healing. It has been estimated that thousands of extracellular matrix repair grafts are used annually to augment surgical repair of rotator cuff tears. The only mechanical assessment of the suitability of these grafts for rotator cuff repair has been made using tensile testing only, and compared grafts to canine infraspinatus. As the shoulder and rotator cuff tendons are exposed to shearing as well as uniaxial loading, we compared the response of repair grafts and human rotator cuff tendons to shearing mechanical stress. We used a novel technique to study material deformation, dynamic shear analysis (DSA).

Methods

The shear properties of four RCT repair grafts were measured (Restore, GraftJacket, Zimmer Collagen Repair and SportsMesh). 3mm-sized biopsy samples were taken and subjected to DSA using oscillatory deformation under compression to calculate the storage modulus (G') as an indicator of mechanical integrity. To assess how well the repair grafts were matched to normal rotator cuff tendons, the storage modulus was calculated for 18 human rotator cuff specimens which were obtained from patients aged between 22 and 89 years (mean age 58.8 years, with 9 males and 9 females). Control human rotator cuff tendons were obtained from the edge of tendons during hemiarthoplasties and stabilisations.

A 1-way ANOVA of all of the groups was performed to compare shear properties between the different commercially available repair grafts and human rotator cuff tendons to see if they were different. Specific comparison between the different repair grafts and normal rotator cuff tendons was done using a Dunn's multiple comparison test.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 10 - 10
1 May 2012
Chaudhury S Holland C Porter D Vollrath F Carr AJ
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Improved understanding of the biomechanics and biology of rotator cuff tendons (RCT) may help reduce high re-rupture rates following repairs, particularly amongst larger tears. This study aims to use novel methods for quantitatively determining differences in the mechanical and thermal properties of intact healthy RCTs compared to torn ‘diseased’ tendons. A common problem in the mechanical testing of small tendon samples is that stress risers at the clamp-tendon interface can obscure measurements. As the shoulder is subject to shear, tension and compression, we developed a novel solution using Dynamic Shear Analysis (DSA), a form of rheology which studies material deformation. As collagen is the main component of RCT, the structure and mechanical properties may be affected by collagen conformational changes. Both dermis and rat tail tendon with increased collagen cross-linking exhibit stronger mechanical properties. Thermal changes detected by differential scanning calorimetry (DSC) can help to quantify collagen structural differences in torn RCT, and has been previously used to study muscle, cartilage and vertebral discs.

There were 79 tears (mean age 65.2 years), which were classified according to the size of the tear as small, medium, large and massive. Two separate 3mm-sized biopsy samples were taken and subjected to DSA using oscillatory deformation under compression. The storage modulus (G') was calculated and used as an indicator of mechanical integrity. 18 control tendon specimens were obtained from patients aged between 22-89 years (mean age 58.8 years) during shoulder hemiarthroplasties and stabilisations. Additionally 7 normal, 7 small and 7 massive frozen specimens were thermally characterized. 3 samples per patient were heated between 20-80oC in hermetically sealed vessels. Useful thermal parameters were measured such as the melting temperature (TM) which apparently represents breaking of the amide-amide bonds and protein chains mobility, the denaturation temperature (TD) which supposedly corresponds to proteins falling out of solution and the denaturation enthalpy (ΔH) which reflects the relative amount of triple helical structure.

Healthy tendons had a significantly higher modulus than torn tendons, indicating that torn tendons are mechanically weaker than normal tendons (p = 0.032). Normal tendons had significantly higher mean shear modulus than tendons with small and massive tears (p<0.01). Overall there was a negative correlation between moduli and severity of tendon tear (r = −0.698, p=0.189). The moduli did not significantly correlate with age, sex, hand dominance, or length of preservation in formalin. Massive RCT tears had significantly higher TM and TD when compared to normal RCT (p < 0.05), unlike small RCT tears. No significant difference was detected between the denaturation enthalpy of the different RCT groups. This case control study has demonstrated that normal RCTs have a significantly higher modulus than torn tendons, indicating that torn tendons have less mechanical integrity. Our study further demonstrated a trend between increasing tear size and decreasing mechanical integrity. This study has also demonstrated differences in some of the thermal properties of normal and torn RCTs. These are likely due to collagen structural changes. A decrease in the denaturation temperature of torn tendons, suggests that the material is intrinsically less stable. Torn tendons with reduced storage modulus and collagen integrity may be less able to withstand mechanical loads following repair. This pilot study provides some preliminary insight into the mechanisms that may contribute to, or represent adaptations to high rates of failure of RCT repairs.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 76 - 76
1 Feb 2012
Walmsley P Kelly M Robb J Annan I Porter D
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Supracondylar fractures of the humerus have historically been treated as an emergency case and operated on at the earliest opportunity. We undertook a study to examine whether surgical timing affects the need for open reduction or peri-operative complications in the type III injuries.

Between August 1995 and August 2004, 534 patients presented and were referred to our unit with these fractures. Those with closed, type III injuries without vascular compromise were selected (171 patients). These were divided into 2 groups: those undergoing surgery less than 8 hours from presentation (126 patients) and those undergoing surgery more than 8 hours from presentation (45 patients).

The two major differences between the two groups were: the delayed group were more likely to undergo open reduction (33.3% v 11.2%, p<0.05) and the mean length of the surgical procedure was increased (105.1 minutes v 69.2 minutes, p<0.05). Delay in treatment of the type III supracondylar fractures is associated with an increased need for open reduction and a longer procedure. We would recommend treating these injuries at the earliest opportunity.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 70 - 70
1 Feb 2012
Watts A Teoh K Beggs I Porter D
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This study investigates the experience of one treatment centre with routine surveillance MRI following excision of sarcoma. Casenotes, MRI and histology reports for fifty-nine patients were reviewed. The primary outcome was the presence of local tumour recurrence and whether this was identified on surveillance or interval scanning. Forty-eight patients had a diagnosis of soft tissue sarcoma, the remaining 11 a primary bone tumour. Fifteen patients had local recurrence (25%). Eight were identified on surveillance scan, and the remaining 7 required interval scans.

Surveillance scanning has a role in the early detection of local recurrence of bone and soft tissue sarcoma.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 5 | Pages 684 - 688
1 May 2011
Fisher NE Patton JT Grimer RJ Porter D Jeys L Tillman RM Abudu A Carter SR

Endoprosthetic replacement of the pelvis is one of the most challenging types of limb-salvage surgery, with a high rate of complications. In an attempt to reduce this and build greater versatility into the reconstruction process, a new type of pelvic endoprosthesis was developed in 2003, based on the old McKee-Farrar prosthesis. This study reviews the outcomes in 27 patients who had an ice-cream cone pelvic prosthesis inserted at two different specialist bone tumour centres in the United Kingdom over the past six years. The indications for treatment included primary bone tumours in 19 patients and metastatic disease in two, and six implants were inserted following failure of a previous pelvic reconstruction. Most of the patients had a P2+P3 resection as classified by Enneking, and most had resection of the ilium above the sciatic notch. The mean age of the patients at operation was 49 years (13 to 81). Complications occurred in ten patients (37.0%), of which dislocation was the most common, affecting four patients (14.8%). A total of three patients (11.1%) developed a deep infection around the prosthesis but all were successfully controlled by early intervention and two patients (7.4%) developed a local recurrence, at the same time as widespread metastases appeared. In one patient the prosthesis was removed for severe pain.

This method of treatment is still associated with high morbidity, but early results are promising. Complications are diminishing with increasing experience.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 371 - 371
1 Jul 2010
Chee Y Teoh K Shortt N Porter D
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Introduction: We conducted a prospective study on 29 patients comparing the medium-term outcome between intramedullary nail fixation and plate fixation in paediatric forearm fractures.

Materials and Methods: The criteria were patients who had a nail (10) or plate fixation (19) for a single or both bones forearm fracture between 2004 and 2006. All these patients were recalled following ethical approval for assessment of their grip strength using a hand dynamometer, forearm and elbow range of movements, scar assessment, POSNA outcome questionnaire and new radiographic views of the forearms.

Results: Mean age of 10.4 years for both groups (4–16), All fractures were caused by low velocity falls. Grip strength is reduced in 83% of patients, comparable in both groups. Elbow flexion is more reduced in the plating group but more reduction in extension in the nailing group. The reduction in forearm pronation (69% of patients) and supination (61%) were comparable in both groups. Using the ‘Manchester scar proforma’; the plating group scored worse with 14/21; nail 11/21. ‘POSNA outcome questionnaire’ score showed the nailing group had 90% excellent or good result and plating group 74%. The moderate and poor POSNA outcome (26% plate, 10% nail) were associated with pain, restricted rotation, bad scarring and difficulty lifting heavy objects. Nails were removed after bony healing but all plates were left in situ. Complete remodeling of forearm bones were seen in all radiographs in both groups. One case of non-iatrogenic ulnar nerve injury and two cases of wound infection were noted; all made full recovery.

Conclusion: The medium-term outcome at 2.5 years following either fixation method is generally comparable and good. The obvious differences were; a higher (better) POSNA score in the nailing group, larger scar formation in plating, elbow extension restriction in nailing and elbow flexion restriction in plating group. Factors that were comparable were grip strength, forearm rotation and radiographic remodeling and outcome.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 398 - 398
1 Jul 2008
Huntley JS Teoh KH Sokhi KV Porter D
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Introduction: Langerhans Cell Histiocytosis (LCH) is a tumour-like condition that runs a variable clinical course. Recent series1,2 have suggested that skeletally immature patients with a solitary bony focus (eosinophilic granuloma) have an especially good prognosis.

Aim: To compare recurrence/progression rates for Scottish patients with solitary eosinophilic granulomas, according to skeletal maturity.

Methods: Retrospective case note review of patients identified from the Scottish Bone Tumour Registry.

Results: We identified 70 cases of biopsy-proven non-spinal eosinophilic granuloma of bone. Of these, 39 were skeletally immature (< 16 years) and 31 were skeletally mature (> 16 years). Follow-up (mean 8.25 years) was either continuing or to discharge/death. On the basis of initial screening (skeletal survey/bone scan), 9 cases (13 %; 4 and 5 patients, from the paediatric and adult groups respectively) were found to have multi-focal disease. Considering those with unifocal disease:

in the immature group, 6 patients (ex 35; 17%) developed a further manifestation of the condition (2 had recurrences at same site; 2 developed a distinct focus in bone; 1 developed a distinct soft tissue lesion causing spinal cord compression; 1 developed diabetes insipidus),

in the mature group, 3 patients (ex 26; 12%) developed a distinct focus in bone but there was no other recurrence/progression.

Conclusions: For this population, these data show that the prognosis for paediatric patients with isolated eosinophilic granuloma of bone must be more guarded than that suggested by other series1,2.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 397 - 398
1 Jul 2008
Watts A Teoh K Evans T Beggs I Porter D
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Introduction: Local recurrence of tumour following definitive treatment of bone or soft tissue sarcoma is a predictor of increased morbidity. Early detection of local recurrence may affect outcome. The role of magnetic resonance imaging (MRI) screening following definitive treatment is controversial. This study investigates the experience of one treatment centre with routine surveillance MRI following treatment of sarcoma.

Methods: Patients were identified from the records of the Regional Sarcoma Group. With Local Ethics Committee approval the casenotes, MRI and histology reports for sixty-five patients who had routine surveillance MRI scans following definitive treatment of sarcoma in a single treatment centre were reviewed. The minimum follow up period was 24 months. The primary outcome was the presence of local tumour recurrence and whether this was identified on surveillance or interval scanning.

Results: There were sixty-four patients identified with a bone or soft tissue sarcoma. All had undergone surveillance scanning biannually for the first year then annually. Six patients with Ewing’s sarcoma were excluded because they had not had surgical excision. Fifty-eight patients (59% men) with a bone or soft tissue sarcoma without metastasis between 1996 and 2003 were available for study. The median age at diagnosis was 53 years (range 6–78 years). Eighty three percent had a diagnosis of soft tissue sarcoma. Ten patients had a primary bone tumour. Fourteen patients had local recurrence (24%). Six were identified on surveillance scan, and the remaining eight required interval scans because of clinical suspicion of tumour recurrence. There were no statistical differences in gender, age, or tumour characteristics between those identified on surveillance or interval scans. All those detected on surveillance had intra-lesional or marginal resections.

Conclusions: Surveillance scanning has a role in the early detection of local recurrence of bone and soft tissue sarcoma. Whether this results improvements in prognosis require longer-term follow up studies.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 399 - 399
1 Jul 2008
Teoh K Watts A Reid R Porter D
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Purpose: The purpose of this study was to determine factors predictive of tumour recurrence, or refracture, following curettage as treatment for pathological fracture of the proximal humerus through a benign bone lesion.

Methods: From a cohort of patients held on a national database the factors predictive of recurrence following surgical curettage in patients with pathological fractures through benign bone tumours of the proximal humerus were examined. Thirty nine cases were identified. The diagnosis was simple bone cyst in 27 patients (69.2%), aneurysmal bone cyst in 4 patients (10.3%), (en)chondroma in 4 patients (10.3%), giant cell tumour in 2 patients (5.1%), benign chondroblastoma in 1 patient (2.6%) and fibroma in 1 patient (2.6%). The mean age was 16.5 years and 70% were male.

Results: Most of the patients presented with a history of trauma (77%). Five patients were excluded as their fractures were not treated with surgical curettage. Twenty two patients (65%) had recurrence of the lesion or re-fracture following curettage. None of the patients in whom the fracture occurred after skeletal maturity had a recurrence. Obliteration of the lesion occurred more frequently in those with greatest initial fracture displacement on pre-operative radiographs and in those with impacted fractures. The average time to union and obliteration of the lesion was 4 months (range 1 to 13 months).

Conclusions: Factors predictive of recurrence following curettage were age under 21 years, undisplaced fractures and fractures without impaction on initial radiographs. Patients with these features should be followed up until obliteration of the lesion or skeletal maturity.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 398 - 398
1 Jul 2008
+Watts A Porter D Simpson A Noble B
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Introduction: In hereditary multiple exostosis (HME) the synthesis of the polysaccharide heparan sulphate (HS) is disrupted. HS-proteoglycans are low affinity receptors involved in fibroblast growth factor signaling. Activation of FGF receptor 3 (FGFr3) on mature chondrocytes leads to growth attenuation rather than stimulation. We tested the hypothesis that in HME chondrocytes with absent or reduced HS-PG synthesis there is impaired response to the FGFr3 ligand and loss of control of chondrocyte proliferation.

Materials and methods: Chondrocytes were harvested from normal growth plate (epiphyseodesis) or HME osteochondroma cartilage cap obtained as surgical discard and cultured to 70% confluence in growth media. Cells were re-plated for experimentation. Growth curves were obtained for cells over a period of 5 days. In addition proliferative responses of healthy and HME chondrocytes were determined after low serum synchronization followed by challenge with FGF 9 (10 and 100ng/ml) and incorporation of BrdU for 2hours every two hours over a twenty eight hour period. Using these techniques it is possible to describe in detail the time dependent entry of cells into S-phase of the cell cycle and compare cell lines and treatment.

Results: Significant differences were observed in the growth characteristics over a five-day period (p< 0.05). Under baseline growing conditions the chondrocytes derived from osteochondroma had a more rapid doubling time when compared with the normal growth plate chondrocyte (2.6+/− 0.6 vs 4.9+/−1.0, p< 0.05). In response to incubation with FGF-9 cells from normal growth plate have a lower peak proportion of cells entering the s-phase than with media alone (7% vs 25%). This inhibition is not observed in chondrocytes from osteochondroma.

Conclusions: It would appear that osteochondroma chondrocytes are resistant to the normal regulatory effect of FGF-9 on cell proliferation. The differential response to FGF may be responsible for the growth differences observed both in-vitro and in-vivo.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 4 | Pages 484 - 487
1 Apr 2008
Watts AC Teoh K Evans T Beggs I Robb J Porter D

This study reports the experience of one treatment centre with routine surveillance MRI following excision of musculoskeletal sarcoma. The case notes, MRI and histology reports for 57 patients were reviewed. The primary outcome was local tumour recurrence detected on either surveillance MRI in asymptomatic patients, or interval MRI in patients with clinical concern. A total of 47 patients had a diagnosis of soft-tissue sarcoma and ten of a primary bone tumour. A total of 13 patients (22%) had local recurrence. Nine were identified on a surveillance scan, and four by interval scans. The cost of surveillance is estimated to be £4414 per recurrence detected if low-grade tumours with clear resection margins are excluded. Surveillance scanning has a role in the early detection of local recurrence of bone and soft-tissue sarcoma.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 74 - 74
1 Mar 2005
Simpson P Reid R Porter D
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Aim: The aim of this study was to look at the presenting features, histological grade, size of primary tumour, method of treatment and patient and doctor delays in upper extremity Ewing sarcoma to observe the effects on local recurrence, metastasis and survival.

Methods: 19 patients with upper extremity Ewing sarcoma were identified using the Scottish Bone Tumour Registry which carries clinical, pathological and radiological data on the majority of bone tumours diagnosed in Scotland over the past 50 years.

Results: With increasing tumour Enneking grade at presentation there was a significantly higher mortality (X2=8.0606, p=0.0178). Patients with a higher grade also had an increased trend towards local recurrence (X2=5.1154, p=0.0775). Grade did not seem to influence the occurrence of metastasis. Patients with larger tumours tended to have a higher mortality (50% vs 27% dead at 5 years). All patients presented clinically with pain and all but two complained of some sort of swelling. It was found that there was a trend towards a higher grade in patients presenting with a longer duration of symptoms (X2=4.6269,p=0.0989). No difference in survival was noted between patients undergoing surgery and chemotherapy and patients undergoing radiotherapy and chemotherapy. Disease-free survival was 100% at both 5 and 10 years for Enneking Grade IIA, 56% at 5 and 10 years for Grade IIB and 0% at 5 years for Grade III.

Conclusions: This study re-emphasises the importance of a delay in diagnosis on outcome. Longer symptom duration results in a higher histological grade at presentation. In turn a higher presenting grade is associated with a higher mortality. In agreement with other studies a larger primary tumour correlates with a poorer outcome. Outcomes in terms of survival are comparable for groups treated with adjuvant radiotherapy or surgery.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 75 - 75
1 Mar 2005
McCullagh R Watts A Reid R Porter D
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The Government has set a target of two weeks for referral of suspicious tumours to specialist centres, but what symptoms should raise suspicion of chondrosarcoma and what factors affect survival and local recurrence? A retrospective study of 320 cases of chondrosarcoma from the Scottish Bone Tumour Registry was performed. Presenting symptoms and were related to tumour grade and duration of disease free status and survival. Pain, swelling and loss of function were the most common presenting features. Rapid progression of pain was significantly associated with high-grade tumours. Longer duration of symptoms from onset to presentation was associated with low-grade tumours. High-grade tumour and metastasis at diagnosis were associated with poor prognosis. Thus, patients with a longer history of symptoms actually appear to have longer disease free survival after presentation. Expert opinion should be sought for patients presenting with pain, swelling and loss of function. Practitioners should make prompt referral of patients presenting with pain that is rapidly increasing in severity.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 116 - 116
1 Feb 2003
Aslam N Lavis G Willis N Porter D Cooke PH
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The SCARF osteotomy is a three dimentional osteotomy for hallux valgus. It combines a lateral release of the adductor hallucis with a lateral and plantar displacement of the first metatarsal. The osteotomy is ‘z’ shaped in the lateral view and displacement of the distal fragment is followed by internal fixation.

In this study we set out to determine whether the SCARF osteotomy was an effective method in the correction of moderate to severe hallux valgus deformity. A prospective radiographic study was performed on 22 cases of SCARF osteotomy with an average age of 52 years (range 25–78). Standardised weight bearing anterior-posterior radiographs were taken preoperatively and at six months post operatively.

The American Foot and Ankle Society guidelines were used for all measurements. Measurements were made using overlay acetate sheets to minimise inter and intra observer error.

These were compared to determine changes in the intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular angle (DMAA) and joint congruency angle (JCA). Correction of sesamoid position and metatarsal length changes were also assessed.

The results showed a median reduction of IMA of 6 degrees, HVA of 16 degrees, DMAA of 6 degrees and an improvement in JCA of 11 degrees. Improvement of the lateral sesamoid displacement from beneath the first metatarsal head was seen postoperatively. Metatarsal length was assessed by comparing the ratio of the length of the first to second metatarsal pre and post operatively. No shortening was found. There was no incidence of avascular necrosis or non-union. This study indicates that the SCARF osteotomy produces effective radiological correction of hallux valgus where there is moderate to high degree of deformity. It also improves sesamoid displacement and avoids shortening of the first metatarsal.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 128 - 128
1 Feb 2003
Taylor A Porter D Cooke P
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Aim

To determine the prevalence and distribution of pain in patients with Charcot-Marie-Tooth disease and the effects of surgery on this pain.

Methods

Members of the Charcot -Marie -Tooth International support group were sent a pain questionnaire. Data about the site, nature, frequency, severity of pain, pain triggers, methods of pain relief and the response to surgery were collected.

Results

There were 399 respondents (233 women and 166 men). The most frequently reported sites of pain were the legs (79%) and feet (77%). Ankle pain was reported by 57%. Walking and exercise were the most frequent pain triggers. Rest was the most common method of modifying pain (60 % of respondents). 32 % found analgesics effective and 39% used heat to relive their pain. The most common sites for surgery were the foot (36%) and ankle (26%). In 43% of patients undergoing foot surgery and 54% of patients undergoing ankle surgery, pain had been increased or introduced following surgery.

Conclusions

Patients with Charcot-Marie-Tooth disease experience significant inherent, and probably neuropathic, pain in addition to pain from mechanical causes. Surgery is unlikely to improve or eliminate pain in these patients. It may introduce pain in some. Surgery should be confined to the treatment of structural problems, as it is often ineffective at relieving pain.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_I | Pages 50 - 51
1 Jan 2003
Porter D Fraser M Dobson-Stone C Monaco A Simpson A
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To identify if disease severity and cancer-risk might depend on genotype in Hereditary Multiple Exostoses (HME).

The discovery that the EXT family of tumour suppressor genes is responsible for Hereditary Multiple Exostoses (HME) now enables correlation of clinical features with genetic defects. Genetic epidemiological studies, such as this, may provide additional data of use to the clinician. In most population-based HME cohorts, the incidence of sarcomatous degeneration has been estimated as 1–5%. This is not high, but occurs at a younger age (on average 2–3 decades younger) than chondrosarcoma in the general population. Genetic stratification might allow a very high-risk subgroup to be identified, within which surveillance for neoplastic change in osteochondromas could be concentrated.

In a pilot study, 29 affected individuals from 17 families with HME were screened for EXT mutation, with mutations identified in 12 families. Pedigrees were obtained and a complete assessment of disease severity made. We have since expanded this cohort; a further 71 affected individuals from 34 families with HME have provided detailed pedigree data and undergone a simple clinical examination to assess number of palpable osteo-chondromas. EXT mutation was assessed by means of fluorescent single-strand conformational polymorphism (f-SSCP) screening, followed by sequencing analysis.

Validation of clinical examination : In those who underwent radiographic examination for clinical purposes, number of palpable osteochondromas correlated strongly with number seen on radiographs at 146 anatomical sites (r= 0.814, p< 0.001), validating the usefulness of clinical examination in a population analysis, and negating the need for a radiographic skeletal survey in individuals at risk from malignant change.

EXT mutation : EXT mutation detection rates for f-SSCP were calculated to be 93%. As suggested in the pilot study, most (84%) were loss-of-function mutations. 60% had not previously been reported in the literature. There were 42 individuals with EXT1 and 29 with EXT2 mutations.

Disease severity and EXT mutation: In the pilot study, median number of palpable osteochondromas were about twice as frequent in the 7 families with EXT1 mutation than in the 5 families with EXT2 mutation (p< 0.05). This was also reflected in overall disease severity scores. In the larger follow-up study, individuals with EXT1 mutation had a median number of 32 osteochondromas, compared with 16 osteochondromas in those with EXT2 mutation (Wilcoxon rank sum test p< 0.0005).

Cancer risk: Six chondrosarcomas occurred, and were only found in individuals with EXT1 mutation.

The observation that osteochondromas are more frequent in patients with EXT1 than EXT2 mutations is an important message in genetic counselling. If disease severity and cancer risk is greater in individuals with EXT1 mutation, screening for neoplastic change might be targeted on this group, in which lifetime risk of malignant change in osteochondromas could be increased to between 5% and 10%.


The Journal of Bone & Joint Surgery British Volume
Vol. 74-B, Issue 6 | Pages 883 - 886
1 Nov 1992
Porter D Holden S Steel C Cohen B Wallace M Reid R

We studied the pedigrees of 17 index patients with osteosarcoma, recording malignant disease and cause of death for first- and second-degree relatives. There were seven cancers and five cancer deaths per 2151.5 person-years in first-degree relatives of osteosarcoma patients under the age of 50 years, a significantly greater incidence than in an age- and sex-matched population group (p < 0.001). This excess of malignancy was largely due to two families which fulfilled the criteria for the Li-Fraumeni cancer family syndrome. Both of these families were shown to have the genetic alterations in the p53 gene which have been implicated in this syndrome. Our study suggests that orthopaedic surgeons seeing new cases of osteosarcoma should arrange screening for familial malignancy.