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Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_15 | Pages 54 - 54
1 Nov 2018
Riffault M Johnson G Hoey D
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Bone tissue experiences continued remodelling in response to changes in its biochemical and biophysical environment. Given the finite lifespan of osteoblasts, this continued bone formation requires replenishment from a progenitor population. Although this is largely believed to be from a skeletal stem cell population, given the limitation in in-vivo markers for this cell type, progress in demonstrating this mechanism is limited. Therefore, we characterized the LepR-Cre mouse strain and evaluated whether LepR positive cells are the progenitor population and if they contribute to the osteoblast population over time and in mechanically-induced bone formation in-vivo. Transgenic mouse strains; B6.129(Cg)-Leprtm2(cre)Rck/J to study LepR-expressing cells and B6.Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze/J as a reporter strain were obtained from Jackson Laboratories. Characterization studies were performed on LepR:tdTomato mice at embryonic stage (19.5dpc), 8 and 12 weeks old. Mice (12 weeks old) were subjected to compressive tibia loading with a 11N peak load for 40 cycles, every other day for 2 weeks. Histological analysis reveal that LepR is expressed from the embryonic stage in various organs including bones. LepR positive cells are found around blood vessels and on bone surfaces. Flow cytometry analysis show the amount of LepR positive cells negative for CD45 and Ter-119 markers inside the bone marrow increases over time and following tibial loading. Mechanical loading induces an increase in bone mass and bone parameters. This model allows us to track and evaluate the role of LepR positive cells as bone forming cells, and to decipher the role of these cells in mechanically-induced bone formation.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_15 | Pages 2 - 2
1 Sep 2016
Goff T Moulder E Johnson G
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To evaluate the safety and efficacy of treating patients with Graf IIa developmental hip dysplasia.

The management of the developmentally immature Graf Type IIa dysplastic hip is controversial. Some authors advocate early treatment with an abduction harness whilst others adopt watchful waiting.

At our institution selective sonographic assessment for developmental dysplasia of the hip (DDH) was established in 1997 with prospective data collection. All infants diagnosed with Graf Type IIa hip(s) were treated with either a Pavlik harness or double nappies, with clinical and sonographic follow up until normalisation. Pelvic radiographs were routinely performed at 8 and 18 months follow up for assessment of residual dysplasia and/or complications of treatment. We evaluated the safety and efficacy of all treated patients between 2005 and 2013.

Complete clinical and radiological follow up (mean 2.1 years, 0.7–6.5) was available for 103 of 118 infants. 69 were treated with a Pavlik harness and 49 with double nappies. The chosen treatment was successful in 110 hips with no documented complications, well developed ossific nuclei on follow up radiographs, and no further treatments undertaken. In the double nappy group 4 infants deteriorated sonographically so were changed to a Pavlik harness with subsequent normalisation and successful treatment.

3 patients required VDRO at age 18 months (17–20) and 1 patient required closed reduction and spica cast treatment at age 11 months. No further complications arose in this group. The 15 patients lost to follow up had successful initial treatment but failed to attend for radiographic review.

Both Pavlik harness and double nappies are safe treatment modalities for Type IIa hip dysplasia. However, sonographic deterioration was observed in both groups with surgical intervention required in the minority, supporting the ongoing treatment of these immature hips.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 51 - 51
1 Mar 2013
Smith S Li L Johnson G Joyce T
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Wear of polymeric glenoid components has been identified as a cause of loosening and failure of shoulder implants1,2 in vivo. A small number of shoulder joint simulators have been built for in vitro wear testing, however none have been capable of testing with physiological motion patterns in three axes and with physiological loading. The Newcastle Shoulder Wear Simulator was designed with three axes of motion, which are programmable so that different activities of daily living might be replicated. The simulator uses three pneumatic cylinders with integral position encoders to move five shoulder prostheses simultaneously in the flexion-extension, abduction-adduction, and internal-external rotation axes. Axial loading is applied with pneumatic cylinders supplied from a pneumatic proportional valve via a manifold, which also supplies a sixth static control station. In order to establish if that the machine can actually perform as intended, commissioning trials were conducted replicating lifting a 0.5 Kg weight to head height as a daily living activity. During the commissioning trials JRI Orthopaedics Reverse VAIOS shoulder prostheses were tested in 50% bovine serum at ambient temperature. The results show that the shoulder joint wear simulator can satisfactorily reproduce a daily living activity deliberately selected for having a large range of motion and loading. Other daily activities, such as drinking from a mug, are less demanding in the ranges of motion and loading and represent no difficulty in being reproduced on the simulator. Now successfully commissioned, this new multi-station shoulder wear simulator can wear test current and new designs of shoulder prosthesis in vitro


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 111 - 111
1 Sep 2012
Raman R Johnson G Shaw C Graham V Cleaver N
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To report the clinical, functional and radiological outcome of consecutive primary hip arthroplasties using large diameter (36mm and above) ceramic bearing couples. We believe this to be one of the first independent series.

We prospectively reviewed 519 consecutive primary THA using fully HAC coated acetabular shell and fully HAC coated stem (JRI Ltd) in 502 patients, with minimum follow-up of 32 months. A Biolox-Delta ceramic liner with an 18 deg taper and Biolox-Delta ceramic head (36mm and 40mm) were used in all cases, by 3 surgeons. None were lost to follow-up. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Return to sports and hobbies were recorded.

Mean age was 64.9 yrs (11–82yrs). There were no dislocations. 50–62mm acetabular shells were used. 36 mm head was used in 92% of cases. No acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (1), peri-prosthetic fractures (1). The mean Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. The Charnley score was 5.7 (5–6) for pain, 5.8 (4–6) for movement and 5.9 (4–6) for mobility. There was a significant improvement in the range of movement of the hip. There was no migration of acetabular component. Acetabular radiolucencies were present around one shell. No acetabular liner wear was demonstrated in CT Scans. Mean inclination was 7.4deg(37–65). Mean EQ-5D description scores and health thermometer scores were 0.84 (0.71–0.92) and 88 (66–96). With an end point of definite or probable loosening, the probability of survival was 100%. Overall survival with removal or repeat revision of either component for any reason as the end point was 99.1%.

The results of this study show an excellent clinical and functional outcome and support the use of a fully coated prosthesis with ceramic bearing couples. We envisage monitoring and prospectively reporting the long-term outcome of this series of patients.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 458 - 458
1 Sep 2012
Raman R Shaw C Johnson G Sharma H Day N Dutta A
Full Access

Introduction

Viscosupplementation is used widely to provide symptomatic relief to patients with knee OA. This study aimed to compare the efficacy and safety of the standard (3×2ml) and single (1×6ml) dosing regimens of hylan G-F 20

Methods

Prospective, randomized, blinded (reviewers), comparative independent study. Inclusion criteria was OA knee pain e 60mm on a 100mm VAS; no prior intra articular (IA) injection. Patients were randomised to recieve 1 × 6mL or 3 × 2mL hylan G-F 20. Follow-up at 1, 6, 12, 26 and 52 weeks. Analgesics prohibited for 24 hours prior to follow-up assessments and NSAID_s for 26 wks. All adverse events (AE) were recorded. Primary outcome measure: Target knee pain (VAS) at 26 weeks. Secondary outcome measures included WOMAC, Oxford knee score, SF12


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 130 - 130
1 Sep 2012
Raman R Johnson G Shaw C Graham N Cleaver V
Full Access

To discuss the rationale, selection criteria, indications, and results of using large diameter ceramic heads in revision hip arthroplasty.

We routinely use Biolox family of ceramic heads and acetabular liners in patients undergoing revision total hip replacements. We present our experience in using ceramic articular bearings over the last 20 years and the switch to larger diameter ceramic heads. We also present our rationale for using a large diameter ceramic head instead of a large metal head.

We reviewed a total of 689 revision arthroplasties over this time period and we report the outcome of large bearing couples with case examples in primary and revision scenarios. Furthermore we compared a subset of patients (110) with large diameter ceramic heads – Biolox Delta 36mm to patients who had metal on metal (large head 42 mm and above) bearing couples. The performance of the ceramic bearing couples will be discussed along with the functional outcome of these patients. We found no difference in the functional, clinical sports activities (UCLA and Tegner scores) between patients who had large metal bearing couples and large ceramic couples. Complication rate was less with the ceramic bearing revision arthroplasties, as was patient satisfaction.

Ceramic bearing couples have stood the test of time and have demonstrated an excellent long term wear properties. The recent introduction of the large diameter couples proves to be an excellent alternative if not the first choice in young, complex primary and revision case scenarios.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 91 - 91
1 Sep 2012
Raman R Singh J Johnson G Sharma H Day N Shaw C
Full Access

Introduction

Viscosupplementation is used widely to provide symptomatic relief to patients with knee OA. This study aimed to compare the efficacy and safety of the standard (3×2ml) and single (1×6ml) dosing regimens of hylan G-F 20.

Methods

Prospective, randomized, blinded (reviewers), comparative independent study. Inclusion criteria was OA knee pain e 60mm on a 100mm VAS; no prior intra articular (IA) injection. Patients were randomised to recieve 1 × 6mL or 3 × 2mL hylan G-F 20. Follow-up at 1, 6, 12, 26 and 52 weeks. Analgesics prohibited for 24 hours prior to follow-up assessments and NSAID's for 26 wks. All adverse events (AE) were recorded. Primary outcome measure: Target knee pain (VAS) at 26 weeks. Secondary outcome measures included WOMAC, Oxford knee score, SF12


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXX | Pages 7 - 7
1 Jul 2012
Grimer R Smith G Johnson G Wilson S
Full Access

Earlier diagnosis is one of the key aims in achieving improved outcomes for patients with cancer. In general, the earlier a tumour is diagnosed, the easier it will be to treat and the greater the chance of cure. We have investigated how tumour size at diagnosis and duration of symptoms, both of which may act as a proxy for delay in diagnosis have varied over a 25 year period and whether there is evidence of improvement.

Data were available for 2568 patients with primary bone sarcomas and 2366 with soft tissue sarcomas. The mean size at diagnosis was 10.7 cm for bone tumours and 9.9cm for soft tissue sarcomas. The size of bone sarcomas had not changed with the passage of time but there had been a slight decrease in the size of soft tissue sarcomas (10.3 cm before 2000 vs 9.6cm after 2000, p=0.03). The duration of symptoms reported by patients varied widely with a median of 16 weeks for bone sarcomas and 26 weeks for soft tissue sarcomas. The median duration of symptoms for bone sarcomas had actually increased since 2000 (16 weeks before to 20 weeks after 2000, p⋋0.01), whilst it remained unchanged for soft tissue sarcomas. Further analysis showed that females tended to present with smaller tumours than males and that slower growing tumours (eg. liposarcoma and chondrosarcoma) tended to be larger and have a longer duration of symptoms than other tumours. 15% of patients with a soft tissue sarcoma had undergone a previous inadvertent excision – and this % has not changed over 20 years. Younger patients had smaller soft tissue soft tissue sarcomas than older patients but there was little difference for bone sarcomas.

Conclusion

This data shows there is huge room for improvement


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 60 - 60
1 May 2012
Raman R Dickson D Angus P Ridge J Johnson G Graham A
Full Access

We aim to report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong HAC coated femoral and acetabular components.

We reviewed 586 consecutive cementless primary THA in 542 patients with a minimum 12-18 year follow-up, performed at one institution between 1986 and 1994. Twenty-eight (32 THA) were lost to follow-up. Clinical outcome was measured using Harris, Charnley and Oxford scores. Quality of life using EuroQol

EQ-5D. Radiographs were systematically analysed.

The mean age was 75.2 years. Dislocation occurred in 12 patients (three recurrent). Re operations were performed in 11 patients (1.9%). Four acetabular and one stem revisions were performed for aseptic loosening. Other re-operations were for infection (two), periprosthetic fractures (two), cup malposition (one), revision of worn liner (two). The mean Harris and Oxford scores were 89 (79–96) and 18.4 (12–32) respectively. The Charnley score was 5.7 for pain, 5.3 for movement and 5.4 for mobility. Acetabular radiolucencies were present in 54 hips (9.7%).

The mean linear polythene wear was 0.06 mm/year. Stable stem by bony ingrowth was identified in all hips excluding one femoral revision case. Mean stem subsidence was 2.2mm (0.30–3.4mm). Radiolucencies were present around 37 (6.6%) stems. EQ- 5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, survival at 12 years was 96.1% for acetabular and 98.3% for femoral components. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 97.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 224 - 224
1 May 2012
Raman R Dickson D Sharma H Angus P Shaw C Johnson G Graham A
Full Access

We report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic (HAC) coated acetabular components.

We reviewed 412 consecutive cementless primary THA using fully coated acetabular shell in 392 patients—with a minimum 12 to 18 year follow-up—performed at two institutions between 1986 and 1994. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study. Fully HAC coated stems were used in all patients. The clinical outcome was measured using Harris, Charnley and Oxford hip scores and the quality of life using EuroQol EQ-5D. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured. The radiographic stability of the acetabular component was determined by Enghs criteria.

The mean age was 74.4 years. The mean Harris and Oxford scores were 87 (78– 97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5-6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in four hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4° (38–65).

Radiolucencies were present around 37 (6.6%) stems. Dislocation occurred in 10 patients (three recurrent). Re-operations were performed in nine patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (three), periprosthetic fractures (one), cup malposition (one) and revision of worn liner (three). Mean EQ-5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 97.1% for acetabular component. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 96.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long-term period.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XIV | Pages 1 - 1
1 Apr 2012
Smith G Johnson G Pirrie S Stocken D Billingham L Grimer R
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Bone and Soft Tissue Sarcomas represent approximately 1% of all malignant tumours. Delays in diagnosis are frequent and the average size of Sarcomas at diagnosis has averaged 10cm for many years. In 1999 guidance was produced by NICE with the aim of leading to the earlier diagnosis of common cancers – including Sarcomas. We have attempted to analyze whether this guidance has had any impact on either the size of the tumours at diagnosis or the symptom duration prior to diagnosis experienced by the patients.

Data for patients referred to the Royal Orthopaedic Hospital in Birmingham between 1992 and 2007 with Bone Sarcomas (n=1592) and Soft Tissue Sarcomas (n=2004) were analysed to determine the effect of the guidance. For Bone Sarcomas the mean size of the tumours decreased from 11.2cm prior to the guidance to 10.7cm after the guidance but the change was not statistically significant (p=0.09). The mean duration of symptoms increased from 18 to 21.2 weeks (p=0.01). For Soft Tissue Sarcomas, mean size fell from 10.8cm to 9.5cm (p<0.001), however the duration of symptoms actually increased from 27.3 to 32.1 weeks (p=0.01). Statistical modelling using restricted cubic splines confirmed these trends in the data.

These results show that whilst there may have been a slight improvement in the size at diagnosis of Soft Tissue Sarcomas, overall most patients still experience a long delay between the onset of symptoms and diagnosis and commencement of treatment. It is difficult to conclude that the early diagnosis guidance produced in 1999 has had a significant effect on the basis of this study. Strategies to improve awareness of the symptoms and clinical features of Bone and Soft Tissue Sarcomas are still urgently required.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IV | Pages 37 - 37
1 Mar 2012
Johnson G Smith G Grimer R
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Objectives

To assess the affects of a delay in diagnosis on the survival rates of Bone Sarcoma (BS) using size and symptom duration as measures of delay.

Methods

All patients diagnosed with a Primary BS from 1970 to 2005 were included. Demographic data concerning age, sex, diagnosis and tumour site were recorded. The data were collected retrospectively from a prospective database, with 2573 patients included. Symptom duration is defined as the length of time the patient was experiencing symptoms for until the date of diagnosis. Survival analysis was performed using Kaplan-Meier curves and Cox Regression was carried out to identify variables affecting outcome.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IV | Pages 36 - 36
1 Mar 2012
Smith G Johnson G Grimer R
Full Access

Objective

Sarcomas are a rare group of tumours, which pose numerous problems regarding correct diagnosis and appropriate management. This study aimed to examine whether symptom duration and tumour size at diagnosis have changed over time, using size and symptom duration as methods of comparison.

Methods

All patients diagnosed with sarcoma were identified retrospectively from a prospective database from 1963 to 2005. Demographic data concerning age at diagnosis, sex and diagnosis were recorded. Data were also collected on duration of symptoms and size of tumour at diagnosis. Symptom duration is defined as the length of time the patient was experiencing symptoms for until the date of diagnosis. Changes in size and symptom duration over time were compared by grouping date of diagnosis into time periods and comparing them against each other using non-parametric statistical analysis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 115 - 115
1 Feb 2012
Johnson G Grimer R
Full Access

Current guidelines suggest that most lumps less than 5cm in size will not be malignant. We reviewed our experiences of small lumps at the Royal Orthopaedic Hospital, Birmingham, in order to try and identify factors associated with malignancy. All referrals to our clinic were included and data on size, symptoms, depth and diagnosis were analysed. We identified 325 patients, with 57 (17.5%) malignant and 268 (82.5%) benign lumps. Size >3cm was the most accurate predictor of malignancy (35.8% malignant vs 9.9% <3cm). 23.6% of lumps reported as increasing size were found to be malignant, compared to 8.6% of those that were not. Pain was found to be a poor predictor of malignancy, with only 15.5% of painful lumps found to be malignant and 18.9% of painless lumps found to be malignant. ‘Size >3cm’ has a sensitivity of 73.6% and a specificity of 56.3%, ‘Depth’ has a sensitivity of 73.6% and a specificity of 30.2%, ‘Increasing in Size’ a sensitivity of 71.4% and a specificity of 56.7% and ‘Pain’ a sensitivity of 33.3% and a specificity of 57.1%. If a lump has none of the above features then one can be 89.5% certain that it is not malignant. If it has 1 feature there is a 16.1% chance of its becoming malignant, 2 features a 58% chance, 3 features an 87% chance and if a lump has all 4 features there is a 93.5% chance of its being found to be malignant.

The main limitation with this study is that the data set is skewed because all lumps referred to the Oncology Department are by their nature suspicious. This study identifies those factors which suggest malignancy in small lumps and provides the basis for carrying out a large, community-based study on all lumps, to identify features associated with malignancy.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 11 - 11
1 Feb 2012
Raman R Dutta A Day N Shaw C Johnson G
Full Access

Aim

To compare the clinical effectiveness, functional outcome and patient satisfaction following intra articular injection with Synvisc¯ and Hyalgan¯ in patients with osteoarthritis (OA) of the knee.

Methods

348 consecutive patients were randomised into two groups to receive either Hylan G-F 20 -Synvisc (n= 181) or Sodium Hyaluronate -Hyalgan (n=167). All patients were prospectively reviewed by independent assessors blinded for the treatment. Knee pain on a VAS were recorded. The functional outcome was assessed using Tegner, UCLA, Oxford knee score and EuroQol-5D scores. VAS was used to quantify patient satisfaction. Mean follow-up was 12 months.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 262 - 262
1 Jul 2011
Woodhouse LJ Petruccelli D Wright J Elliott W Toffolo N Patton S Samanta S Sardo A MacMillan D Johnson G Anderson C Evans W
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Purpose: Reducing wait times for total hip (THA) or knee (TKA) joint arthroplasty is a Canadian health care priority. Models that maximise the capacity of advanced practice clinicians (nurses, physical therapists, sports medicine specialists) have been established to streamline care. Hospitals across the Hamilton Niagara Haldimand Brant Local Health Integration Network in Ontario collaborated to establish a Regional Joint Assessment Centre (RJAC). This study was designed to profile patients deemed suitable for surgical review, and to examine wait times for THA or TKA in RJAC patients compared to those referred directly to an orthopaedic surgeon’s office.

Method: Patients referred to the RJAC between July 2007 and August 2008 with knee or hip OA were included. Self-reported function was evaluated using the Oxford Hip and Knee Score that is scored out of 60 (higher scores reflect greater disability). Time to surgery was measured as the number of days from initial review to surgery. Group one consisted of patients that were referred to the RJAC while group two was comprised of patients who were referred directly to a surgeon’s office. Patient characteristics were examined using univariate analyses. Independent t-tests were used to examine between group differences.

Results: One hundred thirty-six patients (mean±sd: 68±2 years, body mass index 31±6 kg/m2, 83 females) with 150 hip and/or knee joint problems were reviewed in the RJAC. Of those, only 33% (45/136 patients) were deemed suitable for surgical review. Self-reported function (Oxford Scores) in the group requiring surgical review was significantly worse (40±7, p=0.03) than in those patients deemed unsuitable for surgical review (37±9). The RJAC group waited on average 130 days for THA and 129 days for TKA (below the provincial target of 182 days) while those referred directly to the surgeons’ offices waited significantly longer (194 days for THA and 206 days for TKA, p< 0.001).

Conclusion: Patients with hip and knee OA who require surgical review have worse self-reported function than those triaged to conservative care. Wait times for THA or TKA were significantly shorter for patients referred to the RJAC under the new model of care than for those referred directly to an orthopaedic surgeon’s office.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 222 - 222
1 May 2011
Raman R Johnson G Sharma H Gopal S Shaw C
Full Access

Aim: To discuss the rationale, selection criteria, indications, and results of using large diameter ceramic heads in primary and revision hip arthroplasty.

Patients and Methods: We routinely use Biolox family of ceramic heads and acetabular liners in patients undergoing total hip replacements. We present our experience in using ceramic articular bearings over the last 20 years and the switch to larger diameter ceramic heads. We also present our rationale for using a large diameter ceramic head instead of a large metal head.

Results: We reviewed a total of 1189 arthroplasties over this time period and we report the outcome of large bearing couples with case examples in primary and revision scenarios. Furthermore we compared a subset of patients (110) with large diameter ceramic heads – Biolox Delta 36mm to patients who had metal on metal (large head 42 mm and above) bearing couples. The performance of the ceramic bearing couples will be discussed along with the functional outcome of these patients. We found no difference in the functional, clinical sports activities (UCLA and Tegner scores) between patients who had large metal bearing couples and large ceramic couples. Complication rate was less with the ceramic bearing arthroplasties, as was patient satisfaction

Conclusion: Ceramic bearing couples have stood the test of time and have demonstrated an excellent long term wear properties. The recent introduction of the large diameter couples proves to be an excellent alternative if not the first choice in young, complex primary and revision case scenarios


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 220 - 220
1 May 2011
Raman R Johnson G Sharma H Gopal S Shaw C Singh J
Full Access

Aim: To report the clinical, functional and radiological outcome of consecutive primary hip arthroplasties using large diameter (36mm and above) ceramic bearing couples. We believe this to be one of the first reported series in the UK.

Methods: We prospectively reviewed 319 consecutive primary THA using fully HAC coated acetabular shell and fully HAC coated stem (JRI Ltd) in 302 patients, with minimum follow-up of 12 months. A Biolox-Delta ceramic liner with an 18 deg taper and Biolox-Delta ceramic head (36mm and 40mm) were used in all cases, which were performed in one institution by 3 surgeons. None were lost to follow-up. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Return to sports and hobbies were recorded.

Results: Mean age was 64.9 yrs (11–82yrs). There were no dislocations. 50–62mm acetabular shells were used. 36 mm head was used in 96% of cases. No acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (1), peri-prosthetic fractures (1). The mean Harris and Oxford scores were 95 (88–97) and 14.1 (12–33) respectively. The Charnley score was 5.7 (5–6) for pain, 5.8 (4–6) for movement and 5.9 (4–6) for mobility. There was a significant improvement in the range of movement of the hip. There was no migration of acetabular component. Acetabular radiolucencies were present around one shell. No acetabular liner wear was demonstrated in CT Scans. Mean inclination was 47.4deg(37–65). Mean EQ- 5D description scores and health thermometer scores were 0.84 (0.71–0.92) and 88 (66–96). With an end point of definite or probable loosening, the probability of survival was 100%. Overall survival with removal or repeat revision of either component for any reason as the end point was 99.1%.

Conclusion: The results of this study show an excellent clinical and functional outcome and support the use of a fully coated prosthesis with ceramic bearing couples. We envisage to monitor and prospectively report the long-term outcome of this series of patients.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 16 - 16
1 Jan 2011
Raman R Eswaramoorthy V Angus P Sharma H Madhu T Shaw C Johnson G
Full Access

We aim to report the clinical, radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic coated acetabular components. We reviewed 412 consecutive primary THA using fully coated acetabular shell in 392 patients, with minimum 12-year follow-up to 18 years, performed at two institutions. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study.

Fully HAC coated stems were used in all patients. Clinical outcome was measured using Harris, Charnley Oxford, EuroQol EQ-5D scores. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured.

Mean age was 74.4 yrs. Dislocation occurred in 10 patients (3 recurrent). Revision operations were performed in nine patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (3), periprosthetic fractures (1), cup malposition (1), revision of worn liner (3). The mean Harris and Oxford scores were 87 (78–97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5–6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in 4 hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4 deg(38–65). Mean EQ-5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 96.1%. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 94.2%.

The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long term period


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 39 - 39
1 Jan 2011
Raman R Madhu T Hamilton R Shaw C Johnson G
Full Access

The aim of this study was to compare the clinical outcome, radiological outcome, activity level and functional outcome of hip resurfacing against metal on metal (MOM) hip arthroplasty.

Matched pairs of patients were selected from consecutive patients who had either MOM arthroplasty (n=236) or hip resurfacing (n=264). We matched 346 patients (173 pairs) in terms of age, sex, diagnosis, and a minimum follow up of 60 months. The functional outcome was assessed using Harris, Charnley-MDP, SF-36, UCLA and Tegner scores. Mean follow up was 67 months (61–80).

Mean age was 54.5 years. Femoral neck fractures were seen in 4 patients in the resurfacing group. The mean acetabular inclination was 42.8 deg and 44.3 deg in the resurfacing and MOM groups. Mean stem subsidence was 1.2mm. Bony ingrowth was seen in ninety six stems and all stems were stable by Engh s criterion. Radiolucent halo was observed around the stem of two resurfacing heads. The mean Harris hip score was 87.9 and 88.2 in the MOM and resurfacing groups respectively (p=0.76). The SF 36 score was 77.8 and 80.1 (p=0.4). The UCLA and Tegner scores were 6.1 and 3.6 for the resurfacing group and 5.9 and 3.9 for the MOM group. Nine patients in the resurfacing group had a postoperative painful limp which settled by 3 months. There was no radiological evidence of implant failure at last follow up. Survival at 5 years was 100% for the MOM group and 94.1% for the resurfacing group.

Functional outcome and activity levels increased in both groups with no difference between the groups. Post operative complications were fewer in MOM group and return to activity was quicker. It appears that resurfacing arthroplasty offers no medium term advantages over MOM arthroplasty. However longer follow up is required to establish the longevity and durability of this implant.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 600 - 600
1 Oct 2010
Thonse R Johnson G
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Aim: We wanted to ascertain if clinical examination confers any additional benefit to secondary/targeted ultrasound screening of neonatal hips.

Materials/Methods: Of the 30585 births (over a 6 year period) in the population served by our hospital, 2742 babies (8.96percent) were referred to the Hip Screening Clinic by the neonatologists and general practitioners. They were examined clinically and by US scans by the specialist consultants. The findings were documented prospectively. Of these, 1862 hips were normal on clinical examination, 841 hips tense (clinical examination inconclusive).

Results: 233 hips were identified as abnormal by the US scans (Graf method). 106 (45percent) of these were normal on clinical examination. In 88 of the hips with abnormal US scans (38percent), clinical examination could not be performed reliably as the babies were tense. None of the hips identified as abnormal on clinical examination were normal on US scans.

Conclusion/Discussion: US scanning of hips in at-risk babies by an experienced paediatric radiologist will identify all the abnormal hips. This will release the paediatric orthopaedic surgeon from routine clinical examination of all these babies. This time can be utilised for running other clinics. Babies found to have abnormal hips on US scanning may be seen by the orthopaedic surgeon for treatment and follow-up. Parents of babies with normal hip US scans may be reassured by a nurse practitioner or a paediatric physiotherapist. This should lead to better utilisation of resources and cost savings.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 389 - 389
1 Jul 2010
Madhu T Akula M Raman R Sharma H Johnson G
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The aim of the paper is to provide an independent single surgeon experience with BHR after a seven-year follow-up.

A cohort of 117 hips in 101 consecutive patients operated by the senior author between Jan 1998 and Dec 2002 were assessed to note their clinical, radiological and functional outcome after a mean follow-up of 7 years (5–9.4 years). Primary osteoarthritis was seen in 73 hips and secondary in 44 hips. Their mean age at surgery was 54 years (range 20–74years). At latest follow-up their mean flexion was 100°and their mean functional outcome scores were respectively: Oxford hip score of 21.5 (12–52, mode 12); Harris hip score of 84.8 (25–100, mode 97), Charnley modification of Merle d’ Aubigné and Postel scores were 4.8 for pain, 4.3 for walking and 5.4 for movement; and SF-36 (physical component 43.9 and mental component 51.45). Failure in the study was defined as revision for any reason. Revision was undertaken in 8 hips (6.8%), five within the first year for periprosthetic fracture neck of femur and 3 hips after the end of 5-year follow-up (2 for advance collapse of the femoral component in patients’ with avascular necrosis of the femoral head and 1 hip for sepsis).

The Kaplan-Meier survival with revision as end point at minimum 5-years of follow-up was 95.7% (95% CI 92–99%) and overall survival at an average 7-years was 91.7% (95% CI 86–97.6%). All the failures were due to the femoral component. However, the reported survival with the use of traditional uncemented and cemented femoral stems is beyond 99% at similar period of follow-up. Patient selection particularly in patients with secondary osteoarthritis is therefore a critical factor when choosing BHR components.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 309 - 309
1 May 2010
Raman R Eeswaramoorthy V Sharma H Anugs P Madhu T Johnson G Shaw C
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Introduction: We aim to report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic (HAC) coated acetabular components.

Methods: We reviewed 412 consecutive cementless primary THA using fully coated acetabular shell in 392 patients, with a minimum 12-year follow-up to 18 years, performed at two institutions between 1986 and 1994. Twenty (22 THA) were lost prior to 12-year follow-up, leaving 372 patients (390 THA) available for study. Fully HAC coated stems were used in all patients. The clinical outcome was measured using Harris, Charnley and Oxford hip scores. Quality of life using EuroQol EQ-5D. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis. Polythene wear was digitally measured. The radiographic stability of the acetabular component was determined by Enghs criteria

Results: The mean age was 74.4 yrs. Dislocation occurred in 10 patients (3 recurrent). Re operations were performed in 9 patients (1.9%). Four acetabular revisions were performed for aseptic loosening. Other re-operations were for infection (3), periprosthetic fractures (1), cup malposition (1), revision of worn liner (3). The mean Harris and Oxford scores were 87 (78–97) and 19.1 (12–33) respectively. The Charnley score was 5.6 (5–6) for pain, 5.2 (4–6) for movement and 5.3 (4–6) for mobility. Migration of acetabular component was seen in 4 hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Mean inclination was 48.4deg(38–65). Radiolucencies were present around 37 (6.6%) stems. Mean EQ–5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 96.1% for acetabular Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 94.2%.

Discusssion and conclusion: The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long term period.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 49 - 50
1 Mar 2010
Thonse R Johnson G
Full Access

Aim: We wanted to ascertain if clinical examination confers any additional benefit to secondary/targeted ultrasound screening of neonatal hips.

Materials and Methods: Of the 30585 births (from 1997–2002) in the population served by our hospital, 2742 babies (8.96 percent) were referred to the Hip Screening Clinic by the neonatologists and general practitioners. They were examined clinically and by US scans by the specialist consultants. The findings were documented prospectively. Of these, 1862 hips were normal on clinical examination, 841 hips tense (clinical examination inconclusive).

Results: 233 hips were identified as abnormal by the US scans (Graf method). 106 (45 percent) of these were normal on clinical examination. In 88 of the hips with abnormal US scans (38 percent), clinical examination could not be performed reliably as the babies were tense. None of the hips identified as abnormal on clinical examination were normal on US scans.

Conclusion/Discussion: US scanning of hips in at-risk babies by an experienced paediatric radiologist will identify all the abnormal hips. This will release the paediatric orthopaedic surgeon from routine clinical examination of all these babies. This time can be utilised for running other clinics. Babies found to have abnormal hips on US scanning may be seen by the orthopaedic surgeon for treatment and follow-up. Parents of babies with normal hip US scans may be reassured by a nurse practitioner or a paediatric physiotherapist. This should lead to better utilisation of resources and cost savings.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 578 - 578
1 Aug 2008
Raman R Dutta A Day N Shaw C Johnson G
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Aim: To compare the clinical effectiveness, functional outcome and patient satisfaction following intra articular injection with Hylan G-F-20 and Sodium Hyaluro-nate in patients with osteoarthritis (OA) of the knee.

Methods: In this independent study, 382 consecutive patients with OA of the knee were prospectively randomized into two groups to receive Hylan G-F-20 -Syn-visc (n=196) or Sodium Hyaluronate -Hyalgan (n=186) and reviewed by blinded independent assessors at pre injection, 6 weeks, 3, 6, 12 months. Knee pain, patient satisfaction was measured on a VAS. Functional outcome was assessed using WOMAC, UCLA, Tegner, Oxford knee score and EuroQol- 5D scores. Mean follow up was 14 months.

Results: Patients in both groups predominantly had grade III OA. Knee pain on VAS improved from 6.7 to 3.2 by 6 weeks (p=0.02) and was sustained until 12 months (3.7, p=0.04) with Synvisc. In the Hyal-gan group, pain improved from 6.6 to 5.7 at 6 weeks (p> 0.05) and to 4.1 at 3 months (p=0.04) but was sustained only until 6 months (5.9, p> 0.05). Improvements in the WOMAC pain and physical activity subscales were significantly superior in the Synvisc group at 3 months (p=0.02), 6 months (p=0.01) and 12 months (p=0.02). General patient satisfaction was better in the Synvisc group at all times although statistically significant at 3 months (p=0.01) and 6 months (p=0.02). There was local increase in knee pain in one patient who received Synvisc, which settled by 4 weeks. Total treatment cost was 23% more in the Hyalgan group due to the two additional visits.

Conclusion: Although both treatments offered significant pain reduction, it was achieved earlier and sustained for a longer period in patients with Synvisc with early increase in activity levels. However, a local reaction of pseudo sepsis was observed with Synvisc in one patient. The total treatment cost, both for the patient and the hospital are higher with Hyalgan. From this study, it appears that the clinical effectiveness and general patient satisfaction are better amongst patients who received Synvisc.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 22 - 22
1 Mar 2008
Thonse R Johnson G
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Of the 30585 births (from 1997–2002) in the population served by our NHS trust, 2742 babies (8.96%) were referred to the hip screening clinic by the neonatologists and general practitioners. They were examined clinically and by US scans by the specialist consultants. The findings were documented prospectively. 233 hips were identified as abnormal by ultrasound scans (Graf). 45% (106) of these were normal on clinical examination. None of the hips identified as abnormal on clinical examination were normal on US scans. In 38% (88) clinical examination could not be reliably performed as the babies were tense.

Of the 1862 hips which were clinically normal, 106 (5.69%) had abnormal ultrasound findings. Furthermore, of the 841 babies who were tense on clinical examination, 88 (10.46%) babies had abnormal ultra-sonographic findings.

Ultrasound scanning of hips in at-risk babies by an experienced paediatric radiologist will identify all the abnormal hips. This will release the paediatric orthopaedic surgeon from routine clinical examination of all these babies. This time can be utilised for running other clinics. Babies found to have abnormal hips on US scanning may be seen by the orthopaedic surgeon for treatment and follow-up. Parents of babies with normal hip US scans may be reassured by a nurse practitioner or a paediatric physiotherapist.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 118 - 118
1 Mar 2008
Wai E Gruscynski A Johnson G Chow D O’Neil J Vexler L
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Back pain is a complex problem affecting the majority of the population at some point in their life. This cross-sectional study evaluated patients presenting to a tertiary spine clinic with a primary complaint of back pain for modifiable lifestyle factors which may be associated with their back pain. Patients were also asked if any of these lifestyle factors had been addressed by primary care practitioners prior to referral to the spine surgeon’s office.

The purpose of this cross-sectional study is to evaluate the modifiable lifestyle factors which may be associated with back pain in patients presenting to a tertiary spine clinic with a primary complaint of back pain and to compare these lifestyle factors with the general population. A secondary objective is to determine whether patients with back pain were given any instructions with regard to modifiable lifestyle factors by their primary care practitioner.

Consecutive patients presenting to the orthopaedic spine surgery clinic at the Ottawa Hospital – Civic Campus are asked to complete a questionnaire upon presentation to the surgeon’s clinic and prior to their visit with the surgeon. Data being collected includes Body Mass Index, smoking history, physical activity history, perceived stress, and disability. Information is also being collected on sources of information about back pain including instructions given by primary care practitioners (physician, chiropractor, physiotherapist, massage therapist, acupuncturist, naturopath, and other). Data will be analyzed to determine the difference in modifiable risk factors between patients presenting to the spine surgery clinic and the general population. Data will also be tabulated for numbers of patients being given information on modifiable lifestyle factors by primary care practitioners.

To date fifty-two patients have completed the questionnaire. A significant difference has been noted between the number of morbidly obese (BMI > 30) patients presenting to the clinic and the general population. It has been noted that less than 20% of primary care physicians have talked about lifestyle modification with their patients prior to referring them to a spine surgeon.

It will be important to know what modifiable lifestyle risk factors this group of patients possesses and which of these modifiable lifestyle risk factors are actually being addressed by primary care practitioners prior to referral to spine surgeons.

The current waiting list for an appointment with a spine surgeon at the Ottawa Hospital is six to eighteen months. If surgeons can help primary care practitioners address some modifiable lifestyle factors with their patients prior to their referral, waiting times may be reduced or at the very least made more comfortable for patients.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 22 - 22
1 Mar 2008
Thonse R Johnson G
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The aim of this study was to ascertain the results and effectiveness of targeted screening of babies.

All the newborn babies (30585 births from 1997 to 2002) in the geographical area served by our trust were assessed by the paediatricians (neonatologists) and general practitioners (GP). They were assessed for abnormal hip examination finding including clinical instability and risk factors for DDH. The risk factors were positive family history, abnormal lie or presentation other than vertex during pregnancy or at birth, oligohydramnios or other congenital abnormalities. On referral, they were assessed clinically and by ultrasound (US) scan in a special Hip screening clinic.

The data were obtained prospectively. Over the period of these six years, 2742 babies were examined in the clinic. Many had more than one risk factor or abnormal hip examination finding (15.9% of babies with abnormal hips and 7.4% of babies with normal hips). Only five babies presented at or after 4 months of age (delayed presentation). They had been treated by the GP (1 patient), at a private hospital (1 patient) or were from outside our area (3 patients). All had abnormal hips on clinical examination. Of these, 3 were 3A or 3B Graf grade (US scan), 1 was 2B and another 2A+.

Screening of babies with above risk factors has identified all patients with abnormal hips in our area, thus avoiding late presentation of DDH. Raising awareness of GPs and paediatricians about these factors should also reduce the number babies to be seen in the hip screening clinic to minimum yet safe levels.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 293 - 293
1 May 2006
Johnson G Smith G Dramis A Grimer R
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To establish whether Patients or Medical Professionals are the main source of delay for patients referred to a Specialist Centre for Soft Tissue Sarcoma.

Methods: Patients were recruited from both outpatient clinics and from the surgical ward. A semi-structured interview was used to take a detailed history of the patients’ treatment pathway, before arriving at the Specialist Centre. Results: The average time for patient to present to a SC from the onset of symptoms was 110 weeks, (min 3 days, max 1089 weeks), with a median of 40 weeks. Average delay to presentation to a medical professional (patient delay) was 24.5 weeks (min 0, max 530), median 2 weeks. Average delay in referral to a SC (service delay) was 84 weeks (min 0 max 1083), median 25weeks.

Discussion: Medical professionals rather than patients contribute the greatest source of delay in patients reaching a Specialist Centre for treatment of Soft Tissue Sarcoma. Adherence to previously published guidelines could decrease this delay. Medical professional awareness of these guidelines and their contents needs to be increased.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_I | Pages 13 - 13
1 Jan 2003
Khaw F Mak P Briggs P Johnson G
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The purpose of this study was to investigate the influence of ligamentous restraints on first metatarsal (MT1) movements in the context of hallux valgus (HV), the surgical correction of which relies on a sound understanding of factors leading to MT1 deformity. Hypermobility or instability of the first metatarsal at its tarsometatarsal joint (TMJ1) is associated with greater degrees of deformity and also greater risk of recurrence after surgery. Recent anatomical work has shown the importance of the plantar aponeurosis (PA), and the transverse ‘tie-bar’ system (TTB) of the metatarsophalangeal (MPJ) plantar plates and intervening deep transverse inter-metatarsal ligaments in the structure and function of the foot. These ligamentous systems are important in MPJ stability, but may also be important at TMJ1.

Ten normal cadaveric feet were dissected to expose the capsules and ligaments of the MPJs and TMTJs and the PA. They were then mounted in plaster of Paris leaving the MT1, MT2, and their articulations free. A loading fixture was constructed so that loads could be applied to MT1 in the transverse plane to produce moments in flexion, abduction or extension. The movements resulting from a load of 40N were measured relative to MT2 using an Isotrak II (Polhemus, US) magnetic measurement system. The tests were performed with the hallux mobile, fixed neutral and fixed dorsiflexed at the MPJ. After an initial test with all structures intact, the PA and the TTB were severed in random order and the test repeated. “Movement maps” were produced showing the range of motion available in different directions and with different ligamentous restraints.

Movement maps suggest that the TMJ1 behaves as a ball and socket joint with no preferred axis of motion. The contributions of the PA and TTB to stiffness in the sagittal plane are small (about 1° movement). However, the TTB provides significant control of the abduction of MT1. The control afforded by the TTB is particularly important since it can ensure that the PA acts to provide an adduction moment about the TMJ1. The integrity of these ligamentous structures is likely to be important in the success of corrective surgical procedures for HV, where disruption can allow up to 10° increase in MT1-2 angles.


The Journal of Bone & Joint Surgery British Volume
Vol. 74-B, Issue 3 | Pages 426 - 430
1 May 1992
Johnson G Thompson A

Between 1979 and 1989, we treated 22 patients with symptomatic lumbar spondylolysis which had not responded to conservative treatment by a modified Scott wiring technique to give direct repair of the lytic defects with stabilisation. The patients' mean age at the time of operation was 15 years; the mean follow-up period was four years. All 19 patients under 25 years old had satisfactory results. Two of the three patients over 25 years old had poor results. The age of the patient at surgery seems to be an important determinant of outcome. Radiologically confirmed fusion is of secondary importance. The presence of a grade I spondylolisthesis did not prejudice the result. We recommend the Scott wiring technique to stabilise the direct repair of a lumbar spondylolysis.


The Journal of Bone & Joint Surgery British Volume
Vol. 71-B, Issue 1 | Pages 43 - 46
1 Jan 1989
Dias J Johnson G Finlay D Stoyle T

We have studied the role of computerised axial tomography in the assessment of the acetabulum before an uncemented Mittelmeier arthroplasty was performed in 20 patients. In the absence of gross anatomical abnormality, computerised tomography did not provide additional information, but in eight patients it was useful in determining adequacy of acetabular depth, anterior acetabular cover, and thickness of the anterior and posterior walls. In these patients, the CT scans provided information which was not available from plain radiographs and greatly assisted in pre-operative planning.