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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 19 - 19
2 May 2024
Shaarani S Moriarty P Vles G Haddad F Konan S
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We had previously reported on early outcomes on a new fluted, titanium, monobloc stem with a three degree taper that has been designed for challenging femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its mid-term clinical and radiographic outcomes.

This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. 85 femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling.

Mean follow-up was 60 months (range 28–84 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Two patients had revision of the stem's one for infection and another for persistent pain.

Positive mid-term clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 18 - 18
2 May 2024
Shaarani S Mohammad O Mohammad A Konan S
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The number of revision total hip arthroplasties (THA) is increasing. This procedure is associated with a higher complication rate than primary THA, and so it is important for patients to have realistic expectations. The aim of this systematic review was to gather and summarise the available evidence on patients’ expectations following revision THA.

A literature search was conducted in PubMed, PsycINFO, Cochrane, Google Scholar and Web of Science from inception to December 2021. Methodological quality was assessed by two independent reviewers using the National Heart, Lung and Blood Institute (NIH) study quality assessment tool for observational cohort and cross-sectional studies.

The search strategy generated 3132 references of which 4 articles met the inclusion criteria. Methodological quality scores ranged from 7–10. Patients have high expectations concerning future walking ability, pain and implant longevity. Implant longevity expectations vary according to the longevity of the primary implant. A significant positive correlation was found between fulfilled expectations of pain and walking ability and patient satisfaction (r = .46 – .47). Only one study assessed fulfilment of patient expectations. Great variability was seen in operationalisation and assessment of expectations.

Patients undergoing revision THA appear to have high expectations with regards to future outcomes. Whilst results are promising, there is a paucity of high-quality data in this area. Further research is needed, which places emphasis on developing a sound theoretical framework for expectations, allowing for the consistent implementation of valid measurement tools.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_7 | Pages 50 - 50
1 Jul 2022
Fontalis A Kayani B Asokan A Haddad IC Tahmassebi J Konan S Oussedik S Haddad FS
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Abstract

Introduction

The postoperative inflammatory response may be implicated in the aetiology of patient dissatisfaction following Total Knee Arthroplasty. Robotic-arm assisted TKA has been associated with reduced bone and soft tissue trauma. The objective of this Randomised Controlled Trial was to compare the inflammatory response in conventional Jig-based versus robotic arm-assisted TKA and examine the relationship with patient reported outcome measures and functional outcomes.

Methodology

30 patients with knee osteoarthritis were randomised to either conventional or robotic-arm assisted TKA. Blood samples were collected for up to 28 days post-operatively and intraarticular drain samples at 6 and 24 hours, to ascertain the systemic and local inflammatory responses. The Spearman's correlation was utilised to evaluate the relationship with PROMs and functional outcomes.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 81 - 81
1 Mar 2021
Yaghmour KM Hossain F Konan S
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Abstract

Objective

In this systematic review we aim to compare wound complication rates from Negative Pressure Wound Therapy (NPWT) to dry sterile surgical dressings in primary and revision total knee arthroplasty (TKA).

Methods

A search was performed using PubMed, Embase, Science Direct, and Cochrane Library. Eligible studies included those investigating the use of NPWT in primary and revision TKA. Exclusion criteria included studies investigating NPWT not related to primary or revision TKA; studies in which data relating to NPWT was not accessible; missing data; without an available full text, or not well reported. We also excluded studies with poor scientific methodology. All publications were limited to the English language. Abstracts, case reports, conference presentations, and reviews were excluded. Welch independent sample t-test was used for the statistical analysis.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 98 - 98
1 Mar 2021
Yaghmour KM Hossain F Konan S
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Abstract

Objective

In this systematic review we aim to analyse the economical impact of using Negative Pressure Wound Therapy (NPWT) in primary total knee arthroplasty (TKA).

Methods

Four medical electronic databases were searched. Eligible studies included those investigating the costs of NPWT in primary TKA. Exclusion criteria included studies investigating cost of NPWT not related to primary TKA. We also excluded studies with poor scientific methodology. We retrieved and analysed data on dressing costs and hospital length of stay (LOS).


Bone & Joint Open
Vol. 2, Issue 2 | Pages 93 - 102
1 Feb 2021
Thompson JW Wignadasan W Ibrahim M Beasley L Konan S Plastow R Magan A Haddad FS

Aims

We present the development of a day-case total hip arthroplasty (THA) pathway in a UK National Health Service institution in conjunction with an extensive evidence-based summary of the interventions used to achieve successful day-case THA to which the protocol is founded upon.

Methods

We performed a prospective audit of day-case THA in our institution as we reinitiate our full capacity elective services. In parallel, we performed a review of the literature reporting complication or readmission rates at ≥ 30-day postoperative following day-case THA. Electronic searches were performed using four databases from the date of inception to November 2020. Relevant studies were identified, data extracted, and qualitative synthesis performed.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 25 - 25
1 Oct 2020
Kayani B Tahmassebi J Ayuob A Konan S Oussedik S Haddad FS
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Introduction

The objectives of this study were to compare the systemic inflammatory reaction, localised thermal response and macroscopic soft tissue injury outcomes in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic total knee arthroplasty (robotic TKA).

Methods

This prospective randomised controlled trial included 30 patients with symptomatic knee osteoarthritis undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localised knee temperature were collected preoperatively and postoperatively at 6 hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned limb alignment and implant positioning in both treatment groups.


Bone & Joint Research
Vol. 8, Issue 12 | Pages 604 - 607
1 Dec 2019
Konan S Abdel MP Haddad FS

There is continued debate as to whether cemented or cementless implants should be utilized in particular cases based upon chronological age. This debate has been rekindled in the UK and other countries by directives mandating certain forms of acetabular and femoral component fixation based exclusively on the chronological age of the patient. This editorial focuses on the literature-based arguments to support the use of cementless total hip arthroplasty (THA), while addressing potential concerns surrounding safety and cost-effectiveness.

Cite this article: Bone Joint Res. 2019;8(12):604–607.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 60 - 60
1 Oct 2019
Kayani B Konan S Horriat S Haddad FS
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Introduction

The objective of this study was to assess the effect of PCL resection on flexion-extension gaps, mediolateral soft tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilised total knee arthroplasty (TKA).

Methods

This prospective study included 110 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted posterior-stabilised TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess gaps pre- and post-PCL resection in knee extension and 90 degrees knee flexion. This study included 54 males (49.1%) and 56 females (50.9%) with a mean age of 68 ± 6.2 years at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1 ± 4.4 degrees varus.


Robotic assisted surgery aims to reduce surgical errors in implant positioning and better restore native hip biomechanics compared to conventional techniques for total hip arthroplasty (THA). The primary objective of this study was to compare accuracy in restoring the native centre of hip rotation in patients undergoing conventional manual THA versus robotic-arm assisted THA. Secondary objectives were to determine differences between these treatment techniques for THA in achieving the planned combined offset, cup inclination, cup version, and leg-length correction.

This prospective cohort study included 50 patients undergoing conventional manual THA and 25 patients receiving robotic-arm assisted THA. All operative procedures were undertaken by a single surgeon using the minimally-invasive posterior approach. Two independent blinded observers recoded all radiological outcomes of interest using plain radiographs. Patients in both treatment groups were well-matched for age, gender, body mass index, laterality of surgery, and ASA scores.

Interclass correlation coefficient was 0.92 (95% CI: 0.84 – 0.95) for intra-observer agreement and 0.88 (95% CI: 0.82–0.94) for inter-observer agreement in all study outcomes. Robotic THA was associated with improved accuracy in restoring the native horizontal (p<0.001) and vertical (p<0.001) centres of rotation, and improved preservation of the patient's native combined offset (P<0.001) compared to conventional THA. Robotic THA improved accuracy in positioning of the acetabular cup within the combined safe zones of inclination and anteversion described by Lewinnek et al (p=0.02) and Callanan et al (p=0.01) compared to conventional THA (figures 1–2). There was no difference between the two treatment groups in achieving the planned leg-length correction (p=0.10).

Robotic-arm assisted THA was associated with improved accuracy in restoring the native centre of rotation, better preservation of the combined offset, and more precise acetabular cup positioning within the safe zones of inclination and anteversion compared to conventional manual THA.

Robotic-arm assisted THA enables improved preservation of native hip biomechanics compared to conventional manual THA.

For any figures or tables, please contact authors directly: fsh@fareshaddad.net


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_12 | Pages 45 - 45
1 Jun 2017
Konan S Eyal G Witt J
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Clinical graphics allows creation of three dimensional simulation based on CT or MRI that allows pre-operative planning. The software reports several hip morphological parameters routinely. Our aim was to validate the measurements of acetabular morphological parameters using CT based clinical graphics in patients presenting with symptomatic hip pain.

We reviewed standardised plain radiographs, CT scans and 3D clinical graphics outputs of 42 consecutive hips in 40 patients presenting with symptomatic hip pain. Acetabular index (AI), lateral centre edge angle (LCE), acetabular and femoral version measurements were analysed for the 3D clinical graphics with radiographs and CT as gold standard.

Significant differences were noted in measurements of AI, LCE, acetabular version and femoral version using the 3D motion analysis versus conventional measures, with only acetabular version showing comparable measurements. Correlation between 3D clinical graphics and conventional measures of acetabular morphology (AI, LCE) showed only slight agreement (ICC <0.4); while substantial agreement was noted for acetabular and femoral version (IC > 0.5).

Acetabular morphological parameters measured by 3D clinical graphics are not reliable or validated. While clinicians may pursue the use of 3D clinical graphics for preoperative non-invasive planning, caution should be exercised when interpreting the reports of hip morphological parameters such as AI and LCE.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_21 | Pages 88 - 88
1 Dec 2016
Greidanus N Konan S Duncan C Masri B Garbuz D
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In revision total hip arthroplasty (THA), acetabular reconstruction while dealing with severe bone loss is a challenge. The porous tantalum revision acetabular shells have been in use for the past decade. Several reports have documented successful use at early to mid-term follow up. There is, however, very little literature around the long-term survival and quality of life outcome with the use of these shells.

We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects reconstructed with a hemispheric, tantalum acetabular shell and multiple supplementary screws. There were 31 females. Average age at revision was 64 years (range 23–85 years). The mean and median follow up was 11 years (range 10–12 years, SD 1). Morselised femoral allograft was used in 34 hips to fill contained cavitary defectes. Bulk femoral allografting was performed in 2 hips.

At a minimum follow-up of 10 (range 10–12) years, the survivorship of the porous tantalum acetabular shell, with revision of the shell as end point was 96%. The minimum 10-year survivorship with hip revision for any reason as end point was 92%. We noted excellent pain relief (mean WOMAC pain 92.6) and good functional outcome (mean WOMAC function 90.3, mean UCLA 5); and generic quality of life measures (mean SF-12 physical component 48.3; mean SF-12 mental component 56.7). Patient satisfaction with pain relief, function and return to recreational activities were noted to be excellent.

Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent clinical and quality of life outcomes at minimum 10-year follow-up. As far as we are aware this is the first report of minimum 10-year follow up of use of this technique for revision hip arthroplasty.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_21 | Pages 82 - 82
1 Dec 2016
Greidanus N Garbuz D Konan S Duncan C Masri B
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Revision surgery for pelvic discontinuity in the presence of bone loss is challenging. The cup-cage reconstruction option has become popular for the management of pelvic discontinuity in the recent years. The aim of this study was to review the clinical, radiological and patient reported outcomes with the use of cup cage construct for pelvic discontinuity at our institution.

Twenty-seven patients (27 cup-cage reconstructions) were identified at median 6-year (minimum 2 year, maximum 10 years) follow up. Eight were female patients. The median age was 77 years [mean 72, range 37–90, SD 13.6]. There were 5 deaths and 2 were lost to follow up.

Two patients were converted to excision arthroplasty; one for infection and one for failure of the construct. A further 3 patients required revision for instability but the cup cage construct was not revised (2 revisions of cemented cups to a constrained cup and one revision of proximal modular component of the femoral prosthesis). Revision of the cup cage construct was not necessary in any of these cases. We noted excellent pain relief (mean WOMAC pain 85.6) and good functional outcome (mean WOMAC function 78.2, mean UCLA 5, mean OHS 78.6). Patient satisfaction with regards pain relief; function and return to activities were noted to be excellent. Radiological changes were noted in further 4 patients (cup migration in one case; fracture of ischial spike in one case and breakage of the cage screws in 2 patients). No migration of the construct was noted in any of the cases.

In conclusion, the cup cage construct is an excellent method of dealing with complex pelvic discontinuity. Our study suggests a low failure rate; high patient satisfaction and pain relief and moderate functional outcome at median 6 year follow up.


The Bone & Joint Journal
Vol. 98-B, Issue 10_Supple_B | Pages 11 - 15
1 Oct 2016
Konan S Haddad FS

Aims

Medial unicompartmental knee arthroplasty (UKA) is associated with successful outcomes in carefully selected patient cohorts. We hypothesised that severity and location of patellofemoral cartilage lesions significantly influences functional outcome after Oxford medial compartmental knee arthroplasty.

Patients and Methods

We reviewed 100 consecutive UKAs at minimum eight-year follow-up (96 to 132). A single surgeon performed all procedures. Patients were selected based on clinical and plain radiographic assessment. All patients had end-stage medial compartment osteoarthritis (OA) with sparing of the lateral compartment and intact anterior cruciate ligaments. None of the patients had end-stage patellofemoral OA, but patients with anterior knee pain or partial thickness chondral loss were not excluded. There were 57 male and 43 female patients. The mean age at surgery was 69 years (41 to 82). At surgery the joint was carefully inspected for patellofemoral chondral loss and this was documented based on severity of cartilage loss (0 to 4 Outerbridge grading) and topographic location (medial, lateral, central, and superior or inferior). Functional scores collected included Oxford Knee Score (OKS), patient satisfaction scale and University College Hospital (UCH) knee score. Intraclass correlation was used to compare chondral damage to outcomes.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_11 | Pages 42 - 42
1 Jun 2016
Volpin A Konan S Tansey R Haddad F
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Introduction

Acetabular revision surgery is becoming more prevalent with an estimated increase of 137% by 2030. It is challenging surgery especially in the presence of deficient bone loss. Several techniques of acetabular reconstruction are used world-wide. The greater the bone loss (Paprosky Type IIIA and IIIB, and AAOS Classification of Acetabular Bone Loss Type 3 and 4) the more complex are the reconstruction methods. There is however, insufficient literature comparing the contemporary techniques of revision acetabular reconstruction and their outcomes.

Objectives

The purpose of this study was to systematically review the literature and to report clinical outcomes and survival of contemporary acetabular revision arthroplasty techniques (tantalum metal (TM) systems, uncemented revision jumbo cups, reinforced devices such as cages and rings, oblong cups and custom-made triflange cups). We specifically looked at outcomes when reconstruction was undertaken in the presence of bone loss.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_19 | Pages 57 - 57
1 Dec 2014
Olivier A Ghani Y Konan S Khan S Briggs TWR Skinner J Pollock R Aston W
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Introduction:

Non-invasive extendible endoprostheses (NIEE) were primarily developed for salvage after musculo-skeletal tumour surgery in the immature skeleton. However, they may also have a unique application to manage complex limb reconstruction in revision surgery to address limb-length inequality in the mature skeleton. The aim of this study is to present the minimum 2 –year results of using non-invasive extendible endoprostheses for complex lower limb reconstruction.

Methods:

Between 2004 and 2013, 21 patients were treated with 23 NIEE. The indication for surgery was salvage of infected prosthesis following primary tumor resection in 6 cases, aseptic prosthesis failure after primary tumour resection in 5 cases, aseptic non-tumor prosthesis failure in 1 case, infected non-tumor prosthesis in 8 cases and symptomatic non-union of graft reconstruction in 3 cases. There were 14 male and 7 female patients with a mean age of 49.8 years (range 19–81).


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 14 - 14
1 Mar 2013
Benjamin-Laing H Konan S Rayan F Manktelow A Haddad FS
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Infected periprosthetic fractures around total hip arthroplasties are increasingly common and extremely challenging problem. The purpose of the study was to review the experience of two tertiary referral units managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants.

Methods

A prospective review of 19 patients managed at two tertiary referral units between 2000 and 2011. Each patient was diagnosed and managed according to similar institutional protocols. Investigation through aspiration and biopsy of periprosthetic tissue supplemented haematological tests to confirm infection. The Cannulock uncoated stem was used in 14 cases, and the Kent hip prosthesis in 5 cases. Allograft struts were used in patients with deficient bone stock.

Results

The mean follow-up for the series was a 53 months (range, 24–99 months). 13 patients underwent definitive revision within 7.9 months (range, 6–10 months; SD, 2.2 months). In 6 cases we implanted an extensively porous-coated stem, in 4 cases a tapered distally fixed cementless stem was used, and in 3 cases a proximal femoral replacement was used. There were no reinfections after the second stage revisions in these patients. 2 patients were offered further staged surgery due to persistently raised inflammatory markers but being mobile and relatively painfree declined. They are being managed in the community on oral antibiotics. Satisfactory outcome was noted in all cases, and in 13 cases, revision to a definitive stem was undertaken after successful control of infection and fracture union. The average postoperative Harris Hip score was 83 (range 79–89). All patients returned to their low to moderate premorbid functional state after discharge.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 115 - 115
1 Jun 2012
Konan S Hossain FS Haddad FS
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Introduction

There have been concerns regarding the quality of training received by Orthopaedic trainees. There has been a reduction in working hours according to the European working times directive. National targets to reduce surgical waiting lists has increased the workload of consultants, further reducing the trainees' surgical experience. Navigation assisted procedures are successfully used in orthopaedics and provides useful feedback to the surgeon regarding precision of implant placement. We investigated the use of navigation aids as an alternative source of training surgical trainees.

Methods

We choose a navigation assisted knee replacement (TKR) model for this study. A first year Orthopaedic registrar level trainee was taught the TKR procedure by a scrubbed consultant in 5 cases. He was then trained in use of non-CT based navigation surgery. The Trainee then performed navigation assisted non-complex primary TKR surgery. A consultant Orthopaedic surgeon was available throughout for advice and support. Data collected included pre and post procedure valgus and varus alignment of the knee, total operative time and WOMAC scores pre and post operatively.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 116 - 116
1 Jun 2012
Konan S Rayan F Meermans G Witt J Haddad FS
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Introduction

In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions.

Methods

In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534-539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 - cleavage lesion; Grade 3 - delamination and Grade 4 –exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa.

For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXII | Pages 27 - 27
1 May 2012
Oddy M Konan S Meswania J Blunn G Madhav R
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Medial Displacement Osteotomy (MDO) of the os calcis is used to correct the hind foot valgus in a flat foot deformity. Screw fixation is commonly used although contemporary locking plate systems are now available. This study tested the hypothesis that a 10mm MDO would support a higher load to failure with a locked step plate than with a single cannulated screw.

Materials and Methods

Eight pairs of embalmed cadaveric limbs harvested 10cm below the knee joint were axially loaded using a mechanical testing rig. Two pairs served as non-operated controls loaded to 4500N. The remaining limbs in pairs underwent a 10mm MDO of the os calcis and were stabilised with a locked step plate or a 7mm cannulated compression screw. One pair was loaded to 1600N (twice body weight) as a pilot study and the remaining 5 pairs were loaded to failure up to 4500N. The force-displacement curve and maximum force were correlated with observations of the mechanism of failure.

Results

In one pair of control limbs, failure occurred with fractures through both os calcis bones, whilst the other pair did not undergo mechanical failure to 4500N. In the pilot osteotomy, the plate did not fail whilst loss of fixation with the screw was observed below 1600N. For the remaining five pairs, the median (with 95% Confidence Intervals) of the maximum force under load to failure were 1778.81N (1099.39 – 2311.66) and 826.13N (287.52 – 1606.67) for the plate and screw respectively (Wilcoxon Signed Rank test p=0.043). In those with screw fixation loaded to 4500N, the tuberosity fragment consistently failed by rotation and angulation into varus.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_IX | Pages 90 - 90
1 Mar 2012
Rhee S Hossain F Konan S Ashby E Haddad F
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Aim

The aim of our study was to assess lateral tracking of the patella with differing designs of Total Knee Arthroplasty (TKA) and compare to that of the native patella.

Method

A modified caliper was used to measure the width and position of the patella relative to the femur at different degrees of knee flexion. The relationship of the patella midpoint to that of the femur was subsequently assessed. Group 1 consisted of 25 native knees. Group 2 consisted of 25 patients with antero-posterior stabilised knee implant with a spherical medial condyle and a deep lateralised patellar groove, and Group 3 consisted of 25 patients with a conventional cam-and-post design with a midline patellar groove. The mean follow-up was 28 months.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 304 - 304
1 Jul 2011
Konan S Rayan F Meermans G Witt J Haddad F
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Introduction: In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions.

Methods: In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534–539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 – cleavage lesion; Grade 3 – delamination and Grade 4 -exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa.

For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics.

Results: We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96).

Discussion: In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 299 - 299
1 Jul 2011
Konan S Soler A Haddad F
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Introduction: The purpose of this study was to assess the efficacy and complications associated with revision hip arthroplasty undertaken in patients under the age group of 55 years.

Methods: A review of our institutions revision hip database showed that 430 revision hip arthroplasties undertaken over the past 9 years had a minimum follow up of 2 years. Of this 84 (56 female, 38 male) patients were under 55 years of age (range 2 to 8 years). The index procedures were preformed at an average age of 46 years (range 15 years to 54 years). The single major etiology of failure was aseptic loosening (74%), followed by infection (8%) and recurrent dislocation (7%). In majority of cases uncemented implants were used at revision surgery (91% femoral stem, 100% acetabular cups). Bone grafts were necessary in 39% of cases.

Results: There was 1% incidence of DVT requiring treatment and 1% incidence of deep infection requiring a further revision hip surgery. There were no cases of dislocation in this series. At final follow up satisfactory progress was noted in all cases with a significant improvement in Harris hip score (p < 0.05).

Discussion: In conclusion, revision of hip arthroplasty in patients below 55 years is associated with improvement in function and patient satisfaction. They perform better than older cohorts but not as good as primary THRs. The complication profile is comparable in the two groups.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 303 - 304
1 Jul 2011
Konan S Rayan F Haddad F
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Introduction: The radiographic evaluation of the antero-lateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. The alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion. The aim of our study was to analyse the reliability of The frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Patients and Methods: Thirty two patients who presented with femoroacetabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

Results: A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Conclusions: Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate measurement of the alpha angle.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 94 - 95
1 May 2011
Hossain F Knott K Patel S Konan S Rayan F Haddad F
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Introduction: Blood transfusion is not uncommon in patients following joint replacement surgery. However, allogeneic transfusion is associated with potential risks ranging from immune mediated allergic reactions to transmission of blood-borne organisms. Furthermore its use has a significant economical impact on healthcare services.

Methods: A retrospective audit of the case notes and haematological records of 196 patients who underwent primary total hip (THR), resurfacing hip (BHR) or total knee replacement (TKR) was carried out. Patients were routinely cross-matched for 2 units of blood if their pre-operative haemoglobin (Hb) levels were < 12g/dL in our cohort. Patient details including age, sex, BMI, comorbidities, and ASA grade were also collected. Surgical parameters such as operation time, tourniquet time (for TKR procedures) and trigger haemoglobin levels (Hb) with timing of transfusion were noted. Statistical analysis was undertaken to identify risk factors for transfusion.

Results: Forty-seven (24%) patients were transfused in our cohort. 78.7% of these patients were appropriately transfused with a trigger Hb of < 8g/dL. Patients transfused with a trigger Hb of > 8g/dL were no different with respect to demographics, procedure type and comorbidities. The average postoperative time interval to transfusion was 2.1 days. Five patients required an intra-operative transfusion. The mean pre-operative Hb levels in transfused and non transfused patients were 12.4 g/dL and 13.5 g/dL respectively. The mean number of units transfused was 2.31. A total of 109 units of blood were used: of these 70 units were cross-matched pre-operatively.

Univariate analysis established a significant relationship between the need for postoperative transfusion and preoperative Hb levels (p< 0.0001), length of surgery (p=0.01), age (p=0.03), history of respiratory disease (p=0.028) and hypertension (p=0.01). There was no significant relationship with respect to ASA grade and procedure type. Multivariate logistic regression analysis revealed pre-operative Hb (p< 0.0001) and age (p=0.015) as the strongest predictors of the need for post-operative transfusion. There is a strong correlation between length of surgery and time interval to transfusion (p=0.037).

Conclusion: Utilisation rates of blood products after primary hip and knee arthroplasty procedures exceed that of what is available from pre-operative cross-matching. In our institution more than 20% of patients may have been transfused inappropriately based upon local guidelines. The decision to cross-match blood pre-operatively for elective arthroplasty procedures should be re-evaluated in light of both patient age and pre-operative Hb levels. Postoperative monitoring of Hb levels should be undertaken early in patients with a prolonged duration of surgery.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 18 - 18
1 Jan 2011
Konan S Kalia P Oussedik S Dodd M Coathup M Haddad F Blunn G
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We investigated the hypothesis that autologous bone marrow stromal cells (BMSC) sprayed on the surface of acetabular cups would improve bone formation and bone implant contact.

Total hip replacements were implanted in 11 sheep, randomly assigned to receive either acetabular implants sprayed with autologous BMSCs suspended in fibrin (study group) or fibrin only (control group). Sheep were sacrificed after six months and the acetabulum with the implant was retrieved and prepared for undcalcified histology. Implant bone contact in both groups was compared, by microscopically noting the presence or absence of new bone or fibrous tissue along the implant at 35 consecutive points (every 1000 μm). The observers undertaking the histological analysis were blinded.

Significantly increased bone implant contact was noted in the BMSC treated group 30.71% ± 2.95 compared to the control group 5.14% ± 1.67 (p = 0.014). The mean thickness of fibrous tissue in contact with the implant was greater at the periphery 887.21mm ± 158.89 and the dome 902.45mm ± 80.67 of the implant in the control group compared to the BMSC treated group (327.49mm ± 20.38 at the periphery and 739.1 mm ±173.72 at the centre). Conversely direct bone contact with the implant surface was significantly greater around the cups with stem cells.

BMSC sprayed on surface of implants improves bone implant contact. Spraying acetabular cups using stem cells could be used in humans where acetabular bone contact is compromised such as in revision procedures.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 42 - 42
1 Jan 2011
Konan S Bull J Haddad F
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Our aim was to ascertain the opinion of Orthopaedic Consultants, General Practitioners, and Patients on the proposed primary care based follow up of joint replacements.

An email questionnaire was sent Orthopaedic Consultants registered with the BOA. Responders had to answer simple questions regarding follow up practices after hip and knee arthroplasty and safe alternatives to the existing system. General practitioners in London were sent a different questionnaire to assess their familiarity with follow up of arthroplasty patients and their competence in identifying complications. Finally, arthroplasty patients were directly questioned on their preference for follow up.

Eigthy-one Orthopaedic Consultants who undertake lower limb arthroplasty responded, 89.06% advocated follow up and review of radiographs by the surgeon. The Arthroplasty Practitioner, the Radiologist and the Physiotherapist were deemed suitable for follow up of patients by 50%, 14.06% and 4.69 % respectively. All responders unanimously disagreed with initial follow up by General Practitioners (0%). However, after a 12 month review, 30.15% thought primary arthroplasty patients could be discharged to the care of their General Practitioner and 11.11% were happy to discharge revision arthroplasty patients. Of the 52 General Practitioners who returned our questionnaire, only 37% were confident of interpreting symptoms related to prosthetic loosening or infection and 98% did not feel competent identifying radiological changes after arthroplasty. 94% of the General Practitioners did not think that they would be happy to follow up arthroplasty patients even if they were offered further training. The reasons for this were lack of specialty skills, work-load concerns, funding issues and surgeons’ duty of care towards the patient. All of the 104 patients who were questioned preferred to be followed up by the arthroplasty team.

In conclusion, Orthopaedic Surgeons, General Practitioners and patients prefer a hospital based dedicated Orthopaedic team for the post operative follow-up of arthroplasty patients.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 505 - 505
1 Oct 2010
Konan S Haddad F Rhee S Tamini N Zhang T
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Radiographs are frequently ordered following acute knee injury. However, it is suggested that only 6 % of patients with a knee trauma have a fracture. Decision rules such as the Ottawa rules and the Pittsburgh rules have been developed to reduce the unnecessary use of radiographs following knee injury.

We prospectively reviewed all acute knee injury patients who were referred to our clinic from the emergency department over a 3 month period. The reason for ordering radiographs was analysed. The Ottawa and the Pittsburgh rules were applied to individual patients to evaluate the need for radiographs. In patients with a diagnosis of fracture, the accuracy of the Ottawa and the Pittsburgh rules was studied.

A total, of 106 patients were referred to the acute knee clinic from the emergency department. 95.28 % (101) of these patients had radiographs of their knee in the emergency department. Five (4.72%) patients had a fracture of their knee and all these cases, the Ottawa and the Pittsburgh knee rules for ordering radiographs was fulfilled. In a vast majority of cases without any fracture, the clinical reason for ordering radiographs was not clear. Using the Ottawa rules for knee radiography 25.47% (27) radiographs could be avoided without missing a fracture. Using the Pittsburgh rules, 30.19 % (32) knee radiographs could be avoided without missing a fracture.

The Ottawa and the Pittsburgh rules have a high sensitivity for the detection of knee fractures. Use of these rules can aid efficient clinical evaluation of the knee in an emergency situation without adverse clinical outcome. They may also have an implication on reducing the work load of radiology department and reduction of health costs.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 522 - 522
1 Oct 2010
Konan S Haddad F Rayan F
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Radiographic evaluation of the anterolateral femoral head is an essential tool for the assessment of cam type of femoroacetabular impingement. Computerised tomography (CT), magnetic resonance imaging and frog lateral plain radiograph views have all been suggested as imaging options for this type of lesion. Alpha angle is accepted as a reliable indicator of cam type of impingement and this may also be used as an assessment tool for successful operative correction of the cam lesion.

The aim of our study was to analyse the reliability of frog lateral view plain radiographs to analyse the alpha angle in cam femoroacetabular impingement.

Thirty two patients who presented with femoroac-etabular impingement were studied. Interobserver reliability for assessment of alpha angles on frog lateral radiographic view was analysed using intraclass correlation coefficient. The alpha angles measured on frog lateral views using digital templating tools were compared to those measured on CT scans.

A high interobserver reliability was noted for the assessment of alpha angles on frog lateral views with a correlation coefficient of 0.83. The average alpha angles measured on frog lateral views was 58.71 degrees (range 32 to 83.3). The average alpha angle measured on CT was 65.11 degrees (range 30 to 102). However, a poor correlation (Spearman r of 0.2) was noted between the measurements using the two systems.

Frog lateral plain radiographs are not reliable predictors of alpha angle. Various factors may be responsible for this such as the projection of the radiographs, patient positioning and quality of images. CT imaging may be necessary for accurate prediction of alpha angle.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 522 - 522
1 Oct 2010
Konan S Guerts J Haddad F Meermans G Rayan F
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The aim of our study was to determine the usefulness of preoperative digital templating of cementless total hip arthroplasty (THA).

60 consecutive cementless THA (synergy stem & reflection cup) were templated digitally by two senior hip arthroplasty fellows (GM, YG) independently. A metallic marker ball of known diameter was used in all images to help scale for magnification. A blinded observer then collated information on the actual implant sizes, size of head component, offset, and level of neck cut intraoperatively. This was used to statistically analyse the correlation (Interclass correlation coefficient) between the digitally templated implant sizes and actual implant sizes used and the reliability of digital templating.

A high rate of coincidence between digitally templated estimates and actual implant sizes was noted for both groups of templates. A high intraclass correlation coefficient (ICC) for the acetabular cup, stem and head were noted (ICC of 0.825, 0.794, and 0.884 respectively). Moderate agreement was noted for neck cut (ICC of 0.567) and leg length (ICC of 0.612).

In conclusion, digital templating can reliably estimate implant sizes in cementless total hip arthroplasty. Valuable information on neck cut and leg length can be obtained by preoperative templating.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 400 - 400
1 Jul 2010
Konan S Haddad F
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We describe our novel approach to managing infected periprosthetic fractures using a revision implant for temporary fracture stabilisation.

A series of 12 consecutive patients aged between 74 and 83 years (average age 81.51, SD 6.32) who were referred to the senior author with periprosthetic fracture and microbiologically proven infection, were managed by radical debridement and antibiotic therapy along with temporary implantion of a long stem cannulated, proximally hydroxyappatite coated and distally locked femoral prosthesis (Cannulock, Orthodesign, Christ-church, UK). Strut grafts, demineralised bone matrix and cable plating system where used in addition where indicated. Post operatively patients were allowed to mobilise as allows and antibiotics were continued until biochemical markers returned to normal.

A good clinical outcome and excellent functional outcome was noted in all 12 cases. No cases of immediate post operative complications such as DVT or PE were noted in any cases. In particular there were no instances of infections associated with prolonged immobilisation and hospital stay. Ten patients underwent a definitive revision hip replacement procedure within an average of 4.3 weeks (range 3.9 to 5.7, SD 2.15). Two patients required a second debridement and delayed definitive treatment due to persistently high inflammatory markers.

We believe that this novel approach significantly improves functional outcome in the management of infected periprosthetic fractures.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 303 - 303
1 May 2010
Konan S Kalia P Oussedik S Coauthup M Dodd M Haddad F Blunn G
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Despite advances in total hip arthroplasty, failure of acetabular cup remains a concern. The role of bone marrow stromal cells (BMSCs) to aid osseointegration of orthopaedic implants have been recently studied. We investigated the hypothesis that autologous BMSCs sprayed on the surface of acetabular cups would improve bone formation and bone implant contact.

Total hip replacements were implanted in 11 sheep, randomly assigned to receive either acetabular implants sprayed with autologous BMSCs suspended in fibrin (study group) or fibrin only (control group). Sheep were sacrificed after six months and the acetabulum with the implant was retrieved and prepared for undecalcified histology. Implant bone contact in both groups was compared microscopically, by noting the presence or absence of new bone or fibrous tissue along the implant at 35 consecutive points (every 1000 μm). The observers undertaking the histological analysis were blinded.

Significantly increased bone implant contact was noted in the BMSC treated group 30.71% ± 2.95 compared to the control group 5.14% ± 1.67 (p = 0.014). The mean thickness of fibrous tissue in contact with the implant was greater at the periphery 887.21mm ± 158.89 and the dome 902.45mm ± 80.67 of the implant in the control group compared to the BMSC treated group (327.49mm ± 20.38 at the periphery and 739.1 mm ± 173.72 at the centre). Conversely, direct bone contact with the implant surface was significantly greater around the cups with BMSCs.

Our data demonstrate that BMSC sprayed on surface of acetabular implants improves bone implant contact. Spraying acetabular cups using stem cells could be used in humans where acetabular bone contact is compromised such as in revision procedures.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 419 - 419
1 Sep 2009
Konan S Haddad F
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Purpose of study: The aim of this study was to look at the clinical outcome of PLC interference screws in knee ligament reconstruction surgery.

Materials & Results: We prospectively followed up 60 patients who underwent primary anterior cruciate ligament (ACL) reconstructions using PLC (Calaxo; Smith & Nephew) screws to secure the graft in the tibial tunnel. [(35 male patients & 25 female). Average age 33.72 years]. In addition to the ACL, PLC screws were used to reconstruct the posterior cruciate ligament in one case and posterior cruciate ligament with the posterolateral corner in another three patients. Hamstring autografts were routinely preferred except in multiple ligament reconstructions, when allografts were also used.

25 (41.67%) patients presented with complications (synovitis in 10 patients, prominent tibial swelling in 21 patients and both in 7 patients). In comparison, no complications were noted in 60 other age and sex matched patients in whom PLLA (Bio RCI; Smith & Nephew) screws were used by the same surgeon.

The symptoms in the PLC screw group often settled conservatively and did not affect knee stability. 6 patients underwent exploration of the tibial tunnel site. A sterile white cheesy substance was noted which was removed, leaving an empty tibial tunnel. The ACL graft was found to be well attached to tibial tunnel in all cases. The PLC screw size did not have any correlation to the occurrence of complications. 2 patients required multiple washouts, one of whom developed a deep infection.

Conclusion: The degradation of PLC screws does not follow the gradual and controlled pattern demonstrated in the ovine model [Walsh WR et all, Arthroscopy. 2007 Jul;23(7):757–65. Comparison of PLLA and PLC interference screws in an ovine ACL reconstruction model.]. The unpredictable screw resorption, and the reaction to it can lead to serious clinical consequences.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 418 - 418
1 Sep 2009
Konan S Haddad F
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Purpose of study: The all inside fixation of meniscal tears with bio-degradable products is popular because of its fast application and reduction in risks of serious neurovascular complications. We reviewed the results of a consecutive series of all inside meniscal repairs performed by the senior author in a carefully selected patient population.

Materials & Results: The senior author performed 104 consecutive meniscal repairs (54 lateral & 50 medial meniscus) in 96 patients (66 male, 30 female), using all inside meniscal repair systems (18 Bionxx, 86 FasT Fix; Smith & Nephew). The average patient age at the time of repair was 31.6 years (range 17 – 46 years). On an average 2 arrows (range 1–4) were used in the Bionnx system and 2.5 sutures (range 1–7) for the Fas T fix system. The predominant tear pattern was a peripheral red on white type tear involving the body and posterior horn. Concomitant ACL reconstruction was undertaken in 50% cases. In 26.9 % cases the repaired meniscus was partially trimmed prior to repair and in 25 % cases a tear of the non repaired meniscus was stabilised by trimming alone. A further arthroscopic partial menisectomy was performed in 12 cases of failed repair (4 Bionxx, 8 Fas T fix) at an average of 16.16 months (range 1 month – 44 months). None of the other patients had symptoms or signs suggestive of meniscal pathology on follow up (minimum 12 months). The repair was successful in 90.69 % of Fas T fix repairs and 77.78 % of Bionxx repairs. The meniscal repair failure rate in the group which had an ACL reconstruction was 5.77 %. No major intra or post operative complications were noted.

Conclusion: Successful meniscal preservation is feasible by using an all-inside meniscal repair device. Patient selection and due consideration to the site and geometry of the meniscal tear is crucial.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 425 - 425
1 Sep 2009
Konan S Rayan F Haddad F
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Purpose of study: The diagnosis of meniscal tears is usually based on the patient’s history and on specific physical tests. Magnetic resonance imaging (MRI) and arthroscopy is often necessary for diagnosis.

Theofilos Karachalios et al. described the new ‘Thessaly test’ and concluded that it could be safely used as a first line screening test for the selection of patients who need arthroscopic meniscal surgery (Ref: J Bone Joint Surg Am. 2005 May; 87(5):955–62). Our objective was to study the role of physical diagnostic tests in screening for meniscal tears and to validate the diagnostic accuracy of the Thessaly test.

Methods & Results: We examined 109 patients [(80 male, 29 female), average age 39.11 years, range (16–66)] who presented with a history suggestive of a meniscal tear. Joint line tenderness,

McMurray’s test and the Thessaly test were assessed by an independent investigator blinded to any imaging data in all patients. MRI and subsequent arthroscopy results were then collated.

Our study showed a much lower diagnostic accuracy for the Thessaly test (61.25 % for medial meniscus and 80 % for lateral meniscus) It is comparable to McMurray’s test (57.14 % for medial meniscus and 77.38 % for lateral meniscus). The Joint line tenderness test has a far superior diagnostic accuracy (80.95 %for medial meniscus and 90.48 % for lateral meniscus). Combining the joint line tenderness test with McMurrays test or the Thessaly test further increased the diagnostic accuracy. Magnetic resonance imaging (MRI) detected 96% of meniscal tears. Arthroscopy was diagnostic and therapeutic in all cases.

Conclusion: Physical tests may not always be diagnostic of meniscal tears. MRI and arthroscopy may be essential in dubious clinical presentations. In our study the Thessaly test in isolation did not have the highest diagnostic accuracy for the detection of meniscal tears but helps increase diagnostic certainty when combined with standard tests.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 288 - 288
1 May 2009
Kalia P Oussedik S Konan S Dodd M Coathup M Blunn G
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Introduction: Aseptic loosening at the bone-implant interface of THA acetabular components is a significant cause of implant failure. This loosening has been attributed either to wear particle-induced osteolysis or to the effects of joint fluid-pressure. It may be possible to prevent the loosening of implants by improving fixation between the bone and implant, or promoting the growth of a biological bony seal, in order to prevent the influx of wear particles or pressurized joint fluid. Additionally in revision implants it is important to promote osseointegration in situations where bone stock may be limited. The hypothesis of this study was spraying autologous BMSCs in fibrin glue onto the surface of HA-coated acetabular components would increase bone formation around the implant and improve bone-implant contact.

Materials and Methods: Bone marrow was aspirated from the iliac crest of six goats, and BMSCs isolated and expanded in vitro. 10 x 10e6 BMSCs were suspended in reconstituted thrombin pre-operatively. A standard posterior approach was used. The acetabular shell was then coated with 2 ml of fibrin glue, with (n=6) or without 10 x 10e6 autologous BMSCs (n=6), and the acetabular component impacted into position. Antibiotic and analgesic prophylaxes were carried out. All animals were weight bearing within 48 hours post-operatively. Walking and ground reaction forces were assessed pre-operatively, as well as 6 and 12 weeks post-operatively. Results were expressed as a percentage of force transmitted through the right leg versus the left leg. After 12 weeks, the acetabulae were retrieved, and processed for histology. The percentage of new bone around the cups was measured within 5 radial zones, using image analysis. Bone-implant contact was also analysed between the new bone and implant surface. Mann Whitney U test was used to show statistical significance.

Results: New bone formation in Zone 5 showed a significant increase in the BMSC group (71.97±10.91%), when compared to the controls (23.85±15.13%, p=0.028). The other zones did not show a significant difference. Overall new bone growth in the BMSC group was 30% greater than the control group (71.42±8.97% and 54.22±16.56%, respectively, p=0.58). Bone-implant contact was significantly improved in the BMSC group (20.03±4.64%), in contrast to the control group (13.71±8.32%, p=0.027). With regards to the force plate analysis, there was no significant difference in loading between groups at both 6 weeks (Controls-79.74±3.63%, BMSCs-59.39±9.33%, p=0.086) and 12 weeks (Controls-86.0%±2.85%, BMSCs-62.33±5.12%, p=0.055).

Discussion and Conclusions: In this study, overall bone growth was greater when cups were treated with BMSCs. Bone-implant contact was significantly improved as well. This study has clinical applications, as using MSCs in fibrin glue promotes a bony seal in contact with the implant which may prevent the migration of particles, or joint fluid, decreasing the likelihood of aseptic loosening of THAs, and improving their longevity. Also, this technique may improve fixation in situations where bone stock is reduced.