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Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 27 - 27
1 Mar 2013
Okoro T Stewart C Al-Shanti N Lemmey A Maddison P Andrew J
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Aim

This study aimed to assess whether the severity of symptoms (assessed with the Oxford Hip Score (OHS)) can relate to the levels of mRNA expression of markers for muscle inflammation (tumour necrosis factor alpha (TNFα), interleukin 6 (IL-6)) in the proximal vastus lateralis (VL) of patients with severe OA undergoing THR.

Methods

Following local research ethics approval and informed consent, 17 patients were prospectively recruited. Muscle biopsies were obtained from the proximal VL (accessed through the surgical wound) intraoperatively whilst the OHS questionnaire was administered preoperatively. mRNA expression for TNFα and IL-6 was assessed using the reverse transcriptase polymerase chain reaction (RT-PCR). The median OHS was used for stratification, with patients above the median classed as having moderate symptoms (MS) and those below classed as having severe symptoms (SS). The effect of SS on muscle inflammation was assessed with relative quotient (RQ) comparison of SS vs. MS mRNA expression.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 33 - 33
1 Mar 2013
Okoro T Lemmey A Maddison P Andrew J
Full Access

Aim

To assess whether the Oxford Hip Score (OHS), is reflective of objectively assessed functional performance (timed up and go (TUG), 30 sec sit to stand (ST), 6 minute walk test (6MWT), stair climb performance (SCP), and gait speed (GS)) in patients undergoing total hip arthroplasty (THA).

Methods

50 patients undergoing THA were prospectively recruited after ethical approval. Demographics and objective physical performance were assessed (TUG, ST, 6MWT, SCP, GS), as was the OHS preoperatively, and at 6 weeks, 6 months and 9 to 12 months postoperatively. Pearson's correlation coefficient was used to assess relationships, with p<0.05 statistically significant.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 9 - 9
1 Mar 2013
Okoro T Maddison P Andrew J Lemmey A
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Introduction

Late (commenced 6 months to 4 years post-op) home-based progressive resistance training programs are proven to improve muscle strength and function after total hip replacement (THR). This study assessed whether early (commenced < 1 week post-op) HBPRT post-THR improves muscle mass, strength and function relative to routine physiotherapy rehabilitation (RPR) at up to 12 months follow up.

Methods

Prospective single blind randomized controlled study performed after ethical approval. 50 patients randomised to 6 week HBPRT (n=26) or RPR (n=24) postoperatively. Maximal voluntary contraction of the operated leg quadriceps in (MVCOLQ) in Newtons (N), sit to stands in 30 seconds (ST, number of repetitions), and the lean mass in grams of the operated leg (LM) were assessed preoperatively and at intervals up to 12 months postoperatively. Mixed model repeated measures ANOVA was used for statistical analysis.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_13 | Pages 29 - 29
1 Mar 2013
Okoro T Stewart C Al-Shanti N Lemmey A Maddison P Andrew J
Full Access

Aim

To assess the relationship between mRNA expression of genetic markers of inflammation (tumour necrosis factor-alpha (TNFα)) and interleukin-6 (IL-6) in the vastus lateralis (VL) of the operated leg, and the strength of the operated leg quadriceps, in patients following THR.

Methods

Following ethical approval, 10 patients were recruited prospectively. Distal VL (5cm proximal to lateral supra-patellar pouch) biopsies were obtained intraoperatively and at 6 weeks post-operatively, with maximal voluntary contraction of the operated leg quadriceps (MVCOLQ) in Newtons(N), assessed preoperatively and at 6 weeks post-op. mRNA expression in the biopsies was assessed using the reverse transcriptase polymerase chain reaction (RT-PCR). Relationships were assessed using Spearman's correlation coefficient (data not normally distributed).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 509 - 509
1 Sep 2012
Thomas G Hossain M Monk A Gill H Glyn-Jones S Andrew J Murray D Beard D Epos Group N
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Introduction

Malalignment of some designs of stem is associated with an increased risk of aseptic loosening and revision. We investigated whether the alignment of the cemented polished, double-taper design adversely affected outcome, in a multicentre prospective study.

Methods

A multicentre prospective study of 1189 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and femoral stem alignment. All patients underwent a primary THR with the Exeter femoral stem (Stryker Howmedica Osteonics, Mahwah, NJ) and a variety of acetabular components. The primary outcome measure was the Oxford hip score (OHS) and change in OHS at five years. Secondary outcomes included rate of dislocation and revision. Radiographic evaluation of the femoral component was also undertaken. The long axis of the Exeter femoral component and the long axis of the femoral canal were located, and the angle at the point of intersection measured. The cementing quality was determined as defined by Barrack et al. Radiolucent lines at the cement-stem and cement-bone interface in the five year radiographs were defined using the zones described by Gruen et al. Subsidence was measured as the vertical dimension of the radiolucency craniolateral to the shoulder of the stem in Gruen zone 1 as described by Fowler et al. Cement fractures were recorded.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVII | Pages 11 - 11
1 May 2012
Hossain M Parfitt D Beard D Darrah C Nolan J Murray D Andrew J
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Introduction

Preoperative psychological distress has been reported to predict poor outcome and patient dissatisfaction after total hip replacement (THR). We investigated this relationship in a prospective multi-centre study between January 1999 and January 2002.

Methods

We recorded the Oxford Hip Score (OHS) and SF36 score preoperatively and up to five years after surgery and a global satisfaction questionnaire at five year follow up for 1039 patients. We dichotomised the patients into the mentally distressed (Mental Health Scale score - MHS <50) and the not mentally distressed (MHS (50) groups based on their pre-operative MHS of the SF36. 776 (677 not distressed and 99 distressed) out of 1039 patients were followed up at 5 years.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 17 - 17
1 May 2012
Khan W Dheerendra S Johnson D Andrew J Hardingham T
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INTRODUCTION

Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis.

MATERIALS AND METHODS

Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 68 - 68
1 May 2012
Khan W Dheerendra S Johnson D Andrew J Hardingham T
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Introduction

Mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. We have previously demonstrated that the infrapatellar synovial fat pad is a rich source of mesenchymal stem cells and these cells are able to undergo chondrogenic differentiation. Although synovial fat pad derived mesenchymal stem cells may represent a heterogenous population, clonal populations derived from the synovial fat pad have not previously been studied.

Materials and Methods

Mesenchymal stem cells were isolated from the infrapatellar synovial fat pad of a patient undergoing total knee arthroplasty and expanded in culture. Six clonal populations were also isolated before initial plating using limiting dilution and expanded. The cells from the mixed parent population and the derived clonal populations were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium for 14 days. Gene expression analyses; glycosoaminoglycan and DNA assays; and immunohistochemical staining were determined to assess chondrogenic responses.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IX | Pages 81 - 81
1 Mar 2012
Khan W Dheerendra S Johnson D Andrew J Hardingham T
Full Access

INTRODUCTION

Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis.

MATERIALS AND METHODS

Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IX | Pages 82 - 82
1 Mar 2012
Khan W Dheerendra S Johnson D Andrew J Hardingham T
Full Access

Introduction

Mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. We have previously demonstrated that the infrapatellar synovial fat pad is a rich source of mesenchymal stem cells and these cells are able to undergo chondrogenic differentiation. Although synovial fat pad derived mesenchymal stem cells may represent a heterogenous population, clonal populations derived from the synovial fat pad have not previously been studied.

Materials and Methods

Mesenchymal stem cells were isolated from the infrapatellar synovial fat pad of a patient undergoing total knee arthroplasty and expanded in culture. Six clonal populations were also isolated before initial plating using limiting dilution and expanded. The cells from the mixed parent population and the derived clonal populations were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium for 14 days. Gene expression analyses; glycosoaminoglycan and DNA assays; and immunohistochemical staining were determined to assess chondrogenic responses.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 307 - 307
1 Jul 2011
Khan W Malik A Tew S Adesida A Andrew J Hardingham T
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Introduction: Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis.

Material and Methods: Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.

Results: Bone marrow derived adherent colony forming cells stained strongly for markers of adult mesenchymal stem cells including CD44, CD90 and CD105, and they were negative for the haematopoietic cell marker CD34 and for the neural and myogenic cell marker CD56. Interestingly, a high number of cells were also positive for the pericyte marker 3G5. Cell aggregates showed a chondrogenic response and in lowered oxygen there was increased matrix accumulation of proteoglycan, but less cell proliferation, which resulted in 3.2-fold more glycosoaminoglycan per DNA after 14 days of culture. In hypoxia there was increased expression of key transcription factor SOX6, and the expression of collagens II and XI, and aggrecan was also increased.

Discussion: Pericytes are a candidate stem cell in many tissue and our results show that bone marrow derived mesenchymal stem cells express the pericyte marker 3G5. The response to chondrogenic culture in these cells was enhanced by lowered oxygen tension, which up-regulated SOX6 and increased the synthesis and assembly of matrix during chondrogenesis. This has important implications for tissue engineering applications of bone marrow derived stem cells.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 314 - 314
1 Jul 2011
Khan W Malik A Anand S Johnson D Andrew J Hardingham T
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Introduction: There is an ever-increasing clinical need for the regeneration and replacement of tissue to replace soft tissue lost due to trauma, disease and cosmetic surgery. A potential alternative to the current treatment modalities is the use of tissue engineering applications using mesenchymal stem cells that have been identified in many tissues including the fat pad. In this study, stem cells isolated from the fat pad were characterised and their differentiation potential assessed.

Materials and Methods: The infrapatellar fat pad was obtained from total knee replacement for osteoarthritis. Cells were isolated, expanded and stained for a number of stem cell markers. For adipogenic differentiation, cells were cultured in adipogenic inducing medium (10ug/ml insulin, 1uM dexamthasone, 100uM indomethacin and 500uM 3-isobutyl-1-methyl xanthine). Gene expression analyses and Oil red O staining was performed to assess adipogenesis.

Results: Cells at passage 2 stained strongly for CD13, CD29, CD44, CD90 and CD105 (mesenchymal stem cell markers). The cells stained sparsely for 3G5 (peri-cyte marker). On gene expression analyses, the cells cultured under adipogenic conditions had almost a 1,000 fold increase in expression of peroxisome proliferator-activated receptor gamma-2 (PPAR gamma-2) and 1,000,000 fold increase in expression of lipoprotein lipase (LPL). Oil red O staining revealed triglyceride accumulation within typical adipogenic morphology, confirming the adipogenic nature of the observed vacuoles, and showed failure of staining in control cells.

Discussion: Fat pad derived stem cells expressed a cell surface epitope profile of mesenchymal stem cells, and exhibited the potential to undergo adipogenic differentiation. Our results show that the human fat pad is a viable potential autogeneic source for mesenchymal stem cells capable of adipogenic differentiation as well as previously documented ostegenic and chondrogenic differentiation. This cell source has potential use in tissue engineering applications.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 72 - 72
1 Jan 2011
Khan W Tew S Adesida A Andrew J Hardingham T
Full Access

Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis.

Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.

Bone marrow derived adherent colony forming cells stained strongly for markers of adult mesenchymal stem cells including CD44, CD90 and CD105, and they were negative for the haematopoietic cell marker CD34 and for the neural and myogenic cell marker CD56. Interestingly, a high number of cells were also positive for the pericyte marker 3G5. Cell aggregates showed a chondrogenic response and in lowered oxygen there was increased matrix accumulation of proteoglycan, but less cell proliferation, which resulted in 3.2-fold more glycosoaminoglycan per DNA after 14 days of culture. In hypoxia there was increased expression of key transcription factor SOX6, and the expression of collagens II and XI, and aggrecan was also increased.

Pericytes are a candidate stem cell in many tissue and our results show that bone marrow derived mesenchymal stem cells express the pericyte marker 3G5. The response to chondrogenic culture in these cells was enhanced by lowered oxygen tension, which up-regulated SOX6 and increased the synthesis and assembly of matrix during chondrogenesis. This has important implications for tissue engineering applications of bone marrow derived stem cells.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 391 - 391
1 Jul 2010
Hossain M Ali A Andrew J
Full Access

Introduction: We prospectively followed all hip fracture patients admitted between 2004–2006, identified cases where the intention was to treat conservatively and compared their functional outcome and mortality with a similar cohort treated surgically over the same period.

Methods: We recorded length of hospital stay, place of discharge, pre and post-fracture mobility and residence, 30 day and 1 yr mortality, re-admission and delayed surgery. The group treated surgically was recruited and matched for age, gender, pre and post fracture mobility, mental confusion and independence with the conservatively treated group.

Results: 25 patients were treated conservatively. 22 patients treated surgically over the same period were recruited. The mean hospital stay was 13 days in both groups. There were 4 extracapsular (3 displaced) and 21 intracapsular fractures (5 displaced) in the conservative arm and 11 extracapsular and 9 intracapsular fractures in the surgically treated arm. 4 patients from the conservative treatment group underwent late surgery 20 days – 2 months after the index event. Surgically treated group had 11 dynamic screw fixation, 1 cannulated screw, 1 total hip replacement and 7 hemiarthroplasty. 9/14 of the conservatively treated patients were mobile independently or with aid after treatment compared to 11/16 patients after surgery. 7/16 patients treated conservatively were living independently in their own residence, compared to 10/14 patients in the operatively treated patients. 1 month and 1 year mortality in conservatively treated group was 4/21 and 7/21 respectively compared to 1/20 and 5/20 in the operative fixation group. There was no statistically significant difference in mobility, residence or mortality between the two groups (Fisher exact test, p > 0.05).

Discussion: Conservative management after hip fracture in medically unfit patients does not result in statistically significant difference in functional outcome or mortality compared to patients treated surgically.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 391 - 392
1 Jul 2010
Hossain M Parfitt D Beard D Murray D Nolan J Andrew J
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Introduction: We investigated the relationship between psychological distress and outcome after total hip replacement (THR) in the Exeter Primary Outcome Study (EPOS).

Materials & Methods: Data were collected from a number of centres across England between January 1999 and January 2002 for patients undergoing primary hip replacement using the cemented Exeter femoral component (Stryker). We recorded the Oxford Hip Score (OHS) for physical function and SF36 questionnaire for both physical and mental domain assessment annually for five years. We dichotomised the patients into the mentally distressed (MHS < 50) and the not mentally distressed (MHS ≥ 50) groups based on their pre-operative Mental Health Score (MHS) from the SF36 score.

Results: Complete data were available for 455 (407 not distressed and 48 distressed) patients. Pre-operative OHS and SF-36 score was significantly worse in the distressed group (both p< 0.001). Mean OHS improved from 43 to 20 at 1 year after surgery and remained the same thereafter in the non distressed group. In the mentally distressed group pre-operative mean OHS of 48 improved to 22 at 1 year after surgery. Maximum improvement in OHS occurred in the 1st yr after surgery. Mean MHS improved from 76 to 81 at 1 year after surgery and remained the same thereafter in the non distressed group. Mean MHS improved from 35 to 62 at 1 year after surgery, reaching 65 at 5 years after surgery in the mentally distressed group. The maximum improvement in MHS occurred in the 1st yr after surgery.

Conclusion: Pre-operative psychological distress did not compromise functional outcome after hip arthroplasty. There was a substantial improvement in mental distress in patients with mental distress prior to surgery. Both groups of patients experienced improvement in Oxford Hip Score, which was maximal by 1 year after surgery and was maintained over the 5 year follow up.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 59 - 59
1 Mar 2010
Khan* W Anand S Tew S Johnson D Andrew J Hardingham T
Full Access

There is an ever-increasing clinical need for the regeneration and replacement of tissue to replace soft tissue lost due to trauma, disease and cosmetic surgery. A potential alternative to the current treatment modalities is the use of tissue engineering applications using mesenchymal stem cells that have been identified in many tissue including the infrapatellar fat pad. In this study, stem cells isolated from the infrapatellar fat pad were characterised to ascertain their origin, and allowed to undergo adipogenic differentiation to confirm multilineage differentiation potential.

The infrapatellar fat pad was obtained from total knee replacement for osteoarthritis. Cells were isolated and expanded in monolayer culture. Cells at passage 2 stained strongly for CD13, CD29, CD44, CD90 and CD105 (mesenchymal stem cell markers). The cells stained poorly for LNGFR and STRO1 (markers for freshly isolated bone marrow derived stem cells), and sparsely for 3G5 (pericyte marker). Staining for CD34 (haematopoetic marker) and CD56 (neural and myogenic lineage marker) was negative. {BR}For adipogenic differentiation, cells were cultured in adipogenic inducing medium consisting of basic medium with 10ug/ml insulin, 1uM dexamthasone, 100uM indomethacin and 500uM 3-isobutyl-1-methyl xanthine. By day 16, many cells had lipid vacuoles occupying most of the cytoplasm. On gene expression analyses, the cells cultured under adipogenic conditions had almost a 1,000 fold increase in expression of peroxisome proliferator-activated receptor gamma-2 (PPAR gamma-2) and 1,000,000 fold increase in expression of lipoprotein lipase (LPL). Oil red O staining confirmed the adipogenic nature of the observed vacuoles and showed failure of staining in control cells.

Our results show that the human infrapatellar fat pad is a viable potential autogeneic source for mesenchymal stem cells capable of adipogenic differentiation as well as previously documented ostegenic and chondrogenic differentiation. This cell source has potential use in tissue engineering applications.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 206 - 206
1 May 2009
Hossain M Sinha A Akhtar H Andrew J
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Purpose: To investigate the value of various clinical signs to identify occult hip fracture.

Methodology: MRI register was searched to identify all patients who had MRI scan between July 2000–June 2006 for suspected occult hip fracture. 64 patients were identified. 33 patients had occult proximal femoral fractures. 27 patients had no fracture.

Results: 19 patients with fracture were not independently mobile compared to 6 patients without fracture. 7 patients with fracture and 2 patients without fracture were able to weight bear. 13 patients with fracture and 10 patients without fracture had unrestricted straight leg raise ability. 7 patients with fracture and 16 patients without fracture had no pain on axial loading. Fisher exact and chi square analysis was performed; with Bonferroni correction for multiple comparisons (10 tests) p< 0.005 was deemed significant. Pain on axial loading of limb and pre-fracture patient mobility were associated with fracture (p< 0.005). Both factors had positive predictive value = 0.76 and post-test probability of disease given a negative test = .30. Predictive values remained the same when both factors were considered together.

Discussion: These data indicate that although patients who were independently mobile before the fall and who do not have pain on axial compression of the limb are less likely to have a fracture, these signs alone or in combination will not exclude a fracture. It is essential to perform MRI scanning of patients with severe hip pain but normal x rays after fall as it does not seem possible to clinically exclude fracture.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 541 - 542
1 Aug 2008
Hossain M Sinha AK Barwick C Andrew J
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Introduction: The possibility of occult hip fracture in older patients after a fall is a common problem. The value of various clinical signs to determine which patients require further investigation has not been reported.

Methodology: MRI register was hand searched to identify all patients who had MRI scan between July 2000–June 2006 for suspected occult hip fracture. 64 patients were identified. 33 patients had occult proximal femoral fractures. 27 patients had no fracture.

Results: More patients with fracture were living in their own home (20/26), were independent for daily living (20/26) and were not independently mobile(19/26) compared to patients without a fracture (14/22, 11/22 and 6/22 respectively). 7 patients with fracture and 2 patients without fracture were able to weight bear. 13 patients with fracture and 10 patients without fracture had unrestricted straight leg raise ability. 7 patients with fracture and 16 patients without fracture had no pain on axial loading. The value of individual tests was evaluated using Fisher exact and chi square analysis; with Bonferroni correction for multiple comparisons (10 tests) p< 0.005 was deemed significant. Pain on axial loading of the limb and pre-fracture patient mobility were both associated with the presence of a fracture (p< 0.005).

Discussion: These data indicate that although patients who were independently mobile before the fall and who do not have pain on axial compression of the limb are less likely to have a fracture, these signs alone or in combination will not exclude a fracture. Other widely used signs (eg ability to straight leg raise) appear of little predictive value. On the basis of our data, we believe it is essential to have a policy of MRI scanning of patients with severe hip pain but normal x rays after a fall as it does not seem possible to clinically exclude a fracture.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 368 - 368
1 Jul 2008
Khan W Adesida A Andrew J Hardingham T
Full Access

Introduction: Autologous chondrocytes harvested from articular cartilage are being used for the repair of focal cartilage defects. The procedure involves injury to the cartilage and alternative sources of stem cells for use in repair are being explored. Stem cells have been found in many tissue including bone marrow and the infrapa-tellar fat pad. Infrapatellar fat pad derived stem cells present a viable and easily accessible source of stem cells for the repair of cartilage defects and tissue engineering applications.

Hypoxia has been shown to improve chondrogenesis in stem cells derived from the bone marrow. We explore the hypothesis that this effect would also apply to stem cells derived from the infrapatellar fat pad.

Materials and methods: Cell aggregates from early passage stem cells isolated from the infrapatellar fat pad were placed in chondrogenic media for 14 days either in a normoxic (20% oxygen) or hypoxic (5% oxygen) environment. Gene expression analysis, DNA and glycosoaminoglycan assays and immunohistochemi-cal studies were performed on the aggregates to assess chondrogenesis.

Results: Cells grown under hypoxic conditions showed significantly improved chondrogenesis as determined by relatively higher gene expression of proteoglycans, collagens and SOX genes. The cell aggregates also had a higher glycosoaminoglycan content and glycosoamino-glycan content per DNA. Immunohistochemical studies confirm enhanced production of collagen types I and II and aggrecan.

Discussion: These findings confirm the previously documented effects of hypoxic culture conditions on stem cells and extend the findings to include infrapatellar fat pad derived stem cells. Our findings suggest that oxygen tension has a role in regulating the function of stem cells as they undergo chondrogenesis. In culture these cells appear to function optimally in an atmosphere of reduced oxygen that more closely approximates documented in vivo oxygen tension. This has important implications in future tissue engineering applications of these cells.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 390 - 390
1 Jul 2008
Awad A Andrew J Williams C Hutchinson C
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Measurement of the rate of fracture healing is a major problem in fracture research. Bone mineral density (BMD) of fracture callus has been used as a measure of healing in diaphyseal fractures. However, metaphyseal fractures (especially in the elderly) are now the commonest type of fracture and are a significant public health problem. This study investigated whether measurement of BMD at the fracture site in the distal radius can be used as a measure of fracture healing.

We recruited 28 patients who had sustained a dorsally displaced distal radial fracture which was deemed to require treatment by intrafocal wire fixation. All patients had acceptable correction of dorsal and radial angle at final x ray (3 months). Wrist function was measured using the Patient Rated Wrist Evaluation (PRWE – a validated outcome measure for use after distal radial fractures), grip strength,and range of motion. All measurements were made at 6, 12 and 26 weeks. BMD was measured at the fracture site (examining the BMD of the medullary bone at the fracture site after removal of wires), in the opposite wrist and the lumbar spine using QCT at 6 weeks after fracture.

There was no correlation between fracture site BMD and BMD at the other wrist or the lumbar spine (r < 0.3). The BMD at the fracture site was higher than the BMD at the other wrist (mean 168 vs 70 HU; p< 0.001 paired T test). There was no relationship between fracture site BMD or the ratio of BMDs fracture site / normal wrist, and any of the functional assessments (proportion grip strength recovered, range of motion or PRWE (r < 0.3)).

15 of these patients underwent a second QCT at 12 weeks after fracture. There was no significant change in fracture site BMD between the first and second scan.

These data indicate that fracture site BMD is unlikely to be a useful method of measuring metaphyseal bone healing. The increase in BMD at the fracture site was unexpected; possible explanations include impaction of bone or high BMD in woven bone (the relationship of which to bone stiffness is uncertain).


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 300 - 300
1 Jul 2008
Andrew J Beard D Nolan J Murray D
Full Access

There has been controversy about the practice of mixing femoral and acetabular implants from different manufacturers in total hip replacement (THR). We studied the clinical outcomes of over 1500 patients in the Exeter Primary Outcomes Study (EPOS) who underwent primary THR with a cemented Exeter stem (Stryker) but with various acetabular components. This was a prospective non-randomised multicentre study. Patient reported hip scores (Oxford Hip Score (OHS)) were measured before operation and at 1 and 2 years post operatively. The choice of acetabular implant was at the surgeons’ discretion. 982 patients had reached four year follow up. Six types of acetabular component were examined (Exeter, Exeter Contemporary, Duraloc (all Stryker), Charnley (DePuy), Cenator (Corin), and Trilogy (Zimmer)).

Patients who received a Charnley cup were found to have worse pre-operative status (significantly higher OHS) than those receiving other cups (especially those receiving Exeter cups) (p< 0.01). Post operatively, this difference continued, with the absolute OHS value remaining greater (i.e. worse clinical result) for the Charnley cup at 1, 2, 3 and 4 years. The association of poor pre-op status with worse post-op result was anticipated. However, when the clinical benefit of surgery (i.e. the improvement in OHS between pre-op and post-op) was assessed, there was no significant difference between the various implants at 1, 2, 3 and 4 years.

These results demonstrate that initial clinical benefit of surgery does not differ between patients receiving acetabular implants from varying manufacturers when the Exeter stem is used. These patients will be followed further to determine whether such “mixing and matching” results in differences in longer term outcomes.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 313 - 313
1 Jul 2008
Andrew J Beard D Nolan J Tuson K Murray D
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The optimal surgical approach for total hip replacement (THR) remains controversial. We report the clinical outcomes of over 1000 patients in the Exeter primary outcomes study (epos) who underwent primary THR with a cemented Exeter stem (Stryker) but with various acetabular components. This was a prospective non randomised multi centre study. Patient reported hip scores (oxford hip score (OHS)) were measured before operation and at 3 months (n= 1312), 1 (n=1276), 2 (n= 1225), 3 (n=1205) and 4 (n=975) years post operatively. Physician reported scores (Merle d’Aubigne / Postel, MDAP) were measured before operation and at 12 months. All of the operations were carried out using either the anterolateral (Hardinge or modification) or posterior approach.

The posterior approach gave better absolute OHS scores at 3 months and 1 year compared with the anterolateral approach. The improvement in OHS between the pre-op and relevant post-op score was better for the posterior than the Hardinge approach, and this extended to 4 years (all p< 0.05). Early dislocation rates were low in both groups. There was significantly more likely to be heterotopic ossification in the Hardinge group, while stem alignment into varus was more common in the posterior approach group. There was no significant difference between the two approaches as measured using the MDAP score at pre-op or at 12 months after surgery.

These results demonstrate that initial patient perceived clinical benefit of surgery is greater using a posterior than with an anterolateral approach. This should be considered when assessing the best approach for a particular patient. The current results emphasise the value of using patient based outcome measures, as the MDAP score did not detect a difference in outcomes between the two groups.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 384 - 384
1 Jul 2008
Awad A Andrew J Williams C Hutchinson C
Full Access

Older fracture patients frequently ask whether their osteoporosis will affect fracture healing. There is only limited previous data about this. We investigated recovery after distal radial fracture, and compared it with BMD of the other distal radius and the lumbar spine (measured using quantitative CT).

All 28 patients had sustained a dorsally displaced distal radial fracture which was deemed to require treatment by intrafocal wire fixation. All patients had acceptable correction of dorsal and radial angle at final x ray (3 months). Wrist function was measured using the Patient Rated Wrist Evaluation (PRWE – a validated outcome measure for use after distal radial fractures), grip strength,and range of motion. All measurements were made at 6, 12 and 26 weeks. BMD was measured in the opposite wrist and the lumbar spine using QCT at 6 weeks after fracture.

There was no correlation between recovery of grip strength (% of contralateral grip strength) at 6,12,or 26 weeks with BMD at either site. Similarly, there was no correlation between BMD and either absolute PRWE scores at any time point or improvement in PRWE between time points. The strongest predictor of recovery of grip appeared to be the proportion of grip recovered at 6 weeks (correlation between% grip recovered at 6 weeks and 3 months r = 0.85; at 6 weeks and 6 months r= 0.56; both p < 0.001). This was not affected by age or variations in measured final dorsal or radial angles or length within this group. It was not affected by degree of preoperative fracture displacement.

These data suggest that recovery of function after distal radial fractures is not influenced by osteoporosis. The data about the importance of initial recovery of grip suggest that factors other than bone position and bone healing may affect rate of functional recovery after distal radial fracture.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 310 - 310
1 Jul 2008
Andrew J Beard D Nolan J Tuson K Murray D
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There has been controversy about whether limb length discrepancy (LLD) affects outcome after total hip replacement (THR). We examined input variables and outcomes of over 1200 patients who received primary THR with the Exeter stem and a variety of acetabular components in the Exeter Primary Outcomes Study. This was a non randomized prospective multi centre study.

We examined whether specific groups of patients or surgeons were more likely to have LLD at one year after surgery. Data for leg length measured on clinical assessment were available for 1207 patients at 1 year. 237 patients were recorded as having a leg length difference of 1 cm or more, and 73 a difference of 2 cm or more. 138 were longer on the operated side and 99 were shorter. The likelihood of having LLD of 2 cm or more was not significantly affected by the grade of surgeon (consultant or trainee), BMI, age of patient, position of patient during surgery or surgical approach, or the use of regional or general anaesthetic.

We examined the effect of LLD on outcomes at 3 months and 1,2,3 and 4 years. Patients with LLD > 1cm had significantly worse Oxford Hip Scores (OHS) at 1, 2, 3 and 4 years (p< 0.01), with the OHS generally being an average 2 points worse in those with LLD. The most consistent difference between those with and without LLD was a patient reported limp on the Oxford Hip Questionnaire.

We conclude that LLD is a common problem after THR and that all patient groups may be affected. It is associated with a significantly worse functional outcome as measured by a validated hip score. Systematic adoption of accurate intra-operative measures of leg length might pay dividends in minimizing this complication.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 306 - 306
1 Jul 2008
Andrew J Beard D Nolan J Murray D
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There is concern that patients undergoing total hip replacement by trainee surgeons may do worse than those operated on by consultants. We examined the clinical outcomes of over patients in the Exeter Primary Outcomes Study who underwent primary THR with a cemented Exeter stem (Stryker) with various acetabular components. Over 1400 patients entered the prospective non-randomised multi centre study. Patient reported hip scores (Oxford Hip Score (OHS)) were measured pre operation and at 3 months, 1,2,3 and 4 years post operatively.

The number of patients assessed at 4 years was 982. Trainees operated on patients with worse pre-operative OHS (p< 0.05; t test)) and on significantly less patients under 60 years (p< 0.05 chi square). There was no significant difference in the improvement in OHS (i.e. pre-op OHS – post-op OHS) at any post-operative time point between consultants and trainees. However, patients operated upon by consultants had consistently better postoperative absolute OHS scores (p< 0.05 at 3 months and 1, 2, 3 and 4 years; t test). Complications were low in both groups. Operations performed by trainees lasted longer (mean of 104 vs. 85 minutes). There was also no difference in OHS scores of patients operated by trainees whether they were assisted by an SHO (n=132) or by a consultant (n=249).

In this large cohort of patients there was no difference in the improvement in OHS between patients operated by registrars and consultants. The difference in the absolute OHS values is likely explained by the difference in pre-operative status. We conclude that THRs performed by consultants and by trainees under appropriate supervision give similar initial clinical results. Given current changes to shorten surgical training, it is important that outcomes of THRs performed by future trainees are reviewed to ensure that outcomes are maintained.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 324 - 324
1 Jul 2008
Khan W Johnson D Andrew J Hardingham T
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Introduction: In this study infrapatellar fat pad (IPFP) derived stem cells were expanded with and without Fibroblast Growth Factor-2 (FGF-2) supplementation and were compared with regards to their ability to proliferate and differentiate into chondrocytes.

Materials and Methods: Cells were isolated from the IPFP tissue and expanded in monolayer culture with and without rhFGF-2 supplementation (final concentration 10ng/ ml). Cell aggregates were placed in chondrogenic media for two weeks. Gene expression studies were carried out using quantitative real time PCR. Immunohistochemical labelling was performed with antibody localisation determined by an immunoperoxidase procedure. The pellets were also weighed and digested in papain for DNA and glycosoaminoglycan (GAG) analysis.

Results: Cells expanded in FGF-2 supplemented media were smaller and proliferated more rapidly. The FGF-2 supplemented cell aggregates also showed 100 times higher expression of collagen type II (COL2A1). Immunohistochemical studies showed that pellets made from FGF-2 treated cells stained more strongly for collagen II and more weakly for collagen I. Pellets made with FGF-2 treated cells were larger, continued with enhanced proliferation and contained more proteoglycan.

Conclusion: Our findings show enhanced proliferation and chondrogenic differentiation in IPFP derived stem cells expanded in FGF-2 supplemented media.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 393 - 393
1 Oct 2006
Evans C Mylchreest S Andrew J
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Mechanical load is crucial to maintaining skeletal homeostasis, but the pathways involved in mecha-notransduction are still unclear. The OPG/RANK/ RANKL triumvirate has recently been implicated in bone homeostasis. These molecules, which are produced by the osteoblast (OPG and RANKL) and the macrophage/osteoclast (RANK), modulate osteoclastogenesis. We have previously shown that cyclical hydrostatic pressure influenced synthesis of various molecules by cultured human macrophages. These factors are important in osteoclastogenesis and bone resorption and have been linked to the development of aseptic loosening. We have also demonstrated that 1,25-dihydroxyvitamin D3 (1,25D3) influences macrophage response to pressure. For this study human macrophages were co-cultured with osteoblasts and subjected to cyclical hydrostatic pressure (34.5x10–3MPa [5.0 psi]) for up to five days, with or without 1,25D3 supplementation. Cells were immunostained for RANK and culture media were assayed for sRANKL and OPG using specific ELISAs. Immunostaining for RANK showed that macrophages subjected to pressure or 1,25D3 supplementation synthesised more RANK than controls. In addition, when exogenous 1,25D3 and hydrostatic pressure were administered simultaneously, immunostaining for RANK was more intense. There was a reciprocal relationship between OPG and sRANKL in co-cultures subjected to pressure. If pressure increased synthesis of sRANKL, OPG was decreased. In cultures where pressure decreased sRANKL, a corresponding increase in OPG was seen. In addition, samples from different individuals responded differently to pressure. The majority of cell populations responded to pressure by increasing OPG synthesis, compared to non-pressurised controls. These results demonstrate for the first time that the OPG/RANK/RANKL complex is sensitive to hydrostatic pressure and that 1,25-dihydroxyvitamin D3 might be involved in this response. These findings suggest a possible transduction mechanism for mechanical load in the skeleton, which has implications for future therapies for aseptic loosening and for skeletal abnormalities such as osteoporosis.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 383 - 383
1 Oct 2006
Evans C Mylchreest S Mee A Berry J Andrew J
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Aseptic loosening is a growing problem for orthopaedic surgeons and the importance of elevated hydrostatic pressure in its development in vivo is now well documented, but the mechanisms by which pressure could enhance loosening are unclear. We have demonstrated that hydrostatic pressures increased MP synthesis of cytokines, chemokines, PGE2 and M-CSF in vitro, all of which are implicated in bone resorption. 1,25-dihydroxy vitamin D3 (1,25D3) has a pivotal role in bone resorption. It stimulates osteoclastic bone resorption and formation, causes fusion of committed osteoclast precursor cells and activates mature osteoclasts in vitro. Under the correct conditions, macrophages (MP) have the ability to differentiate into osteoclasts. Research has shown that MP can synthesise 1,25D3 and changes in this synthesis occur during MP differentiation. We therefore examined how the application of hydrostatic pressure to MP in vitro influenced their synthesis of 1,25D3. In this study, normal human peripheral blood MP (5x105/ml) were cultured for 7 days then exposed to physiological pressure (34.5x10-3MPa) and/or UHMWPE particles (8mg/ml) and the effect on synthesis of 1,25D3 by endogenous 1a-hydroxylase (1aOHase) was studied. MP were incubated with H3-25, hydroxy vitamin D and 1,25D3 synthesis was analysed by HPLC. 1,25D3 synthesis was increased in cells under pressure by an average of 17% compared to static controls. In situ hybridisation (ISH) was used to demonstrate expression of 1aOHase. Image analysis showed a small increase in 1aOHase mRNA in response to pressure and to particles, and a larger increase to the two stimuli simultaneously. Expressed as % of maximum +Pressure + Particles 100%;+ Particles 59%; +Pressure 37%; No Stimulus < 0.1%. These results suggest that 1,25D3 may be one of the factors which stimulates osteoclastic bone resorption in aseptic loosening. As both these stimuli are likely to be present in vivo, such synthesis could further exacerbate loosening.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 248 - 248
1 May 2006
Barlow D Hill V Hopgood P Andrew J
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This paper describes the surgical indications and technique for lateral femoral cutaneous neurectomy in the hip following formation of a neuroma post surgery.

We would like to present a single surgeon series of the treatment of localised trochanteric pain post total hip replacement. It is believed that in certain cases localised pain in the line of the scar is attributable to formation of a neuroma of the posterior branch of the lateral femoral cutaneous nerve of the thigh.

Method We have reviewed a consecutive series of 5 patients who underwent this procedure for unremitting pain following THR. Of the 5 patients 4 underwent unilateral neurectomy and one underwent a bilateral neurectomy. All had persistent pain before the operation with a positive Tinnel’s test.

Results Of all the patients, 4 said that their pain was improved after the operation and would undergo the operation again. One had no improvement at all. None were worse after the operation.

Conclusion We believe selective neurectomy to be a good procedure in this often, difficult clinical situation.

Several case reports will highlight the findings on history and examination and the technique used.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 172 - 173
1 Feb 2003
Mushtaq N Khan A Sochart D Andrew J
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Cross match practice for patients with femoral neck fractures continue to cause concern due to a failure of compliance to the existing protocols. We addressed this issue by conducting a number of studies over three years and we report the summation of the studies and demonstrate the reasons for the poor compliance. We provide a simple and effective protocol that has helped reduce preoperative cross matching of femoral neck fractures from 71% to 16.7% two years after its introduction.

Study 1

Retrospective review of the cross-match practice for 240 femoral neck fractures and reviewed the changes in pre-operative and post-operative haemoglobin levels and association with surgical procedure.

Study 2.

Postal questionnaire of 129 anaesthetic and orthopaedic trainees assessing the perceived cross-match requirements of patients with femoral neck fractures based on preoperative haemoglobin values between 8–13g/dl. In addition reviewed the source of trainees perceptions and practice

Study 3

Review of the efficiency of the cross-match protocol two years after its introduction Results

Study 1

71% patients with femoral neck fractures were cross-matched at admission but only 29% of the patients were subsequently transfused. From the 384 units of blood ordered at admission 230 were returned unused. Inter-trochanteric fractures had a mean blood loss of 3.1g/dl (range 1.5–7.2g/dl) following surgery in comparison to a mean loss of 1.7g/dl (0.9–3.4g/dl) for patients with displaced subcapital fractures

Study 2

Orthopaedic trainees at all levels of training requested more blood then their anaesthetic counterparts for patients with femoral neck fractures. There was misconceptions regarding blood loss following surgery amongst all trainees and only 14.3% trainees used existing literature to guide their cross-match practice where as 53.4% devised protocols based on their own or colleagues’ experience.

Study 3

Cross-match protocol was working effectively. Only 16.7% of the patients with femoral neck fractures were cross-matched on admission.

Conclusion

Cross-match recommendations fail to influence trainees. In order to address this we produced a protocol that does not rely on orthopaedic trainees. The haematology MLSO provides the appropriate amount of preoperative blood for the patient based on our finding of blood loss of different fracture patterns and the patients’ preoperative haemoglobin level. Our results show our protocol is still effective two years following its introduction despite numerous changes in trainees during this period.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 100 - 100
1 Feb 2003
Knight D Gilbert FJ Gillan MGC Andrew J Grant AM Wardlaw D
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The role of MRI or CT in the management of patients with LBP, for whom there is no clear clinical indication for the use of sophisticated imaging, is uncertain. The aim of The Scottish Back Trial was to determine whether early use of MRI or CT influences clinical management and outcome of patients with LBP and whether it is cost-effective.

Elective patients were new referrals to orthopaedic or neurosurgeons with symptomatic lumbar spine disorders (without ‘red flags’). After obtaining informed consent, patients were randomised to ‘early imaging’ (imaging as soon as practicable) or ‘delayed, selective imaging’ (imaging only if an imperative clinical indication developed). Principal outcomes measures were the SF-36, questionnaire, the Aberdeen LBP Scale and the EQ-5D. Patients completed questionnaires at trial entry and after 8 and 24 months.

From 15 hospitals, 2657 patients were assessed and 783 were recruited and randomised. Eight months and twenty-four months after trial entry, comparison of data abstracted from case notes indicated that, apart from the use of imaging, both groups had received similar clinical management. At follow-up, an improvement in health status, as measured by the SF-36 and Aberdeen LBP Scale, was reported by both groups. At 24 months, there was a statistically significant but small difference in favour of the ‘early imaging’ group (p=0. 002) as measured by the Aberdeen LBP Scale but no difference in the SF-36 except a marginal improvement in the bodily pain subscale.

The use of MRI or CT imaging for this group of LBP patients did not significantly affect their management. The clinical significance of the marginal improvement in health status in the ‘early imaging’ group is uncertain. The results of the cost-effectiveness analysis may clarify whether a policy of ‘early imaging’ would be a cost effective use of resources.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 243 - 243
1 Nov 2002
Cheung K Kaluarachchi T Lu W Andrew J Kwan K Cheah K
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Introduction: Collagen type X is secreted by hypertrophic chondrocytes during fracture repair. Its precise role is uncertain. This study uses a knockout mouse model in which the collagen X gene is removed to examine its function.

Method: Bilateral femoral fractures were created in type X collagen knockout mice (mutant) and normal mice (wild type), and were stabilized using an external fixator. The mice were sacrificed 7, 10, 14, 21, 28 and 60 days after fracture. Fracture healing was followed by x-rays, histology, gene expression studies, immuno-histochemistry and mechanical testing.

Results: In the mutant mice, bony union was delayed, there was abnormal persistence of aggrecan up to 60 days after fracture. Histology reviewed amorphous acellular areas surrounded by osteoclasts at 21 and 28 days, while mechanical testing revealed that at 14 days after fracture, mutant callus was stiffer than the wild type, but the trend is reversed at 28 and 60 days.

Discussion: This study contributes to the understanding of the basic mechanisms involved in fracture repair. The data suggest that collagen type X plays a significant role in bone remodeling during fracture healing. Its absence results in delayed union and abnormalities within the fracture callus.