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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_4 | Pages 12 - 12
3 Mar 2023
Dewhurst H Boktor J Szomolay B Lewis P
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Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year. Higher BMI or ASA scores are associated with worse pre-operative hips and worse final outcome score. Despite this, the Delta OHS increases with increased BMI shown in the 55–80 year old female patients and male patients under 60. Key Words: THR, Uncemented, Oxford hip score, outcome


Bone & Joint Open
Vol. 3, Issue 6 | Pages 510 - 514
1 Jun 2022
Hoggett L Frankland S Ranson J Nevill C Hughes P

Aims. Hip and knee arthroplasty is commonly performed for end-stage arthritis. There is limited information to guide golfers on the impact this procedure will have postoperatively. This study aimed to determine the impact of lower limb arthroplasty on amateur golfer performance and return to play. Methods. A retrospective observational study was designed to collect information from golfers following arthroplasty. Data were collected from 18 April 2019 to 30 April 2019 and combined a patient survey with in-app handicap data. Results. A total of 2,198 responses were analyzed (1,097 hip and 1,101 knee). Of the respondents, 1,763 (80%) were male and the mean age was 70 years (26 to 92). Hip arthroplasty was associated with a mean increase in handicap of 1.03 (95% confidence interval (CI) 0.81 to 1.25). No difference was seen between isolated leading or trailing leg (p = 0.428). Bilateral hip arthroplasty increased handicap (p < 0.001). Overall, 1,025 (94%) maintained or increased the amount of golf played, 258 (23.5%) returned to iron shots at six weeks, 883 (80%) returned to club competitions at six months, 18 (1.6%) had persistent pain, and 19 (1.7%) were unable to return to play. Knee arthroplasty was associated with a mean increase in handicap of 1.18 (95% CI 0.99 to 1.38). Trailing leg arthroplasty alone was associated with higher postoperative handicap (p = 0.002) as was bilateral surgery (p = 0.009). Overall, 1,009 (92%) maintained or increased the amount of golf played, 270 (25%) returned to iron shots at six weeks, 842 (76%) returned to club competition at six months, 66 (6%) had persistent pain, and 18 (1.6%) were unable to return to play. Conclusion. Hip and knee arthroplasty enables patients to maintain or increase the amount of golf played. The majority return to competitions within one year. Return to iron shots occurs from six weeks. A small increase in handicap following surgery is expected and is larger in patients undergoing bilateral surgery or those with knee arthroplasty to their trailing leg. Patients may still experience pain when playing golf. Cite this article: Bone Jt Open 2022;3(6):510–514


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_14 | Pages 8 - 8
1 Nov 2021
Hube R
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In recent years, there has been increasing interest in the use of simultaneous hip arthroplasty compared to staged procedures in patients with bilateral pathology. The aim of this study was to compare simultaneous and staged hip arthroplasty in patients with bilateral pathology by assessing the transfusion rate, postoperative hemoglobin drop, length of stay (LOS), in-hospital complications, 30-days readmissions, leg length difference and early functional outcome.

We conducted a retrospective cohort study that included all patients who were undergoing primary total hip arthroplasty (THA) by a single surgeon in a high-volume arthroplasty center between 2015 and 2020 as simultaneous or staged procedures. Staged bilateral arthroplasties were performed within 12 months and were stratified by the time between procedures. Data was acquired through the electronic files at the Orthopädische Chirurgie München (OCM). For functional outcome we compared the ability of the patients to walk independently on the ward and the ability to walk a set of stairs alone which was recorded daily by the attending physiotherapist.

In total n=290 patients were assessed for eligibility and included in this study. One hundred and thirty eight patients were allocated to the staged arthroplasty group. The second staged procedure was performed within 12 months of the first procedure. One hundred and fifty two patients were allocated to the simultaneous arthroplasty group. No statistical difference was found between the two groups regarding demographic data. Primary outcome measurements: There was no significant difference in transfusion rate or complication rate (p=0.1147). In both groups the transfusion rate was actually 0%. Secondarily, no statistically significant difference was found between the postoperative hemoglobin drop (p=0.1147) and the functional outcome (p=0.7249), nor the length of stay (LOS) (p=: 0.6415), as well as the 30 days readmission rate between both groups. No difference was found in leg length in the simultaneous group. The OR time in the simultaneous group ranged from 62min to 111min with an average of 77min. No surgery exceeded a 120min window.

We observed no significant differences in transfusion rate, in hospital complications, as well as readmission rate between both groups. The early functional outcome showed no significant difference in mobility. Simultaneous hip arthroplasty is as safe as a staged procedure, with no higher risk for the patient, in a specialized high volume center with a specialized surgeon and an adequate team. Level of evidence: Level IV


The Bone & Joint Journal
Vol. 103-B, Issue 7 Supple B | Pages 25 - 32
1 Jul 2021
Amstutz HC Le Duff MJ

Aims

Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre.

Methods

A total of 355 patients (400 hips) were treated with Conserve Plus HRA between November 1996 and November 2000. There were 96 female (27%) and 259 male patients (73%). Their mean age was 48.2 years (SD 10.9). The University of California, Los Angeles (UCLA) hip scores and 12-item Short Form Survey (SF-12) quality of life scores were reported. Survivorship was assessed using Kaplan-Meier analyses.


The Bone & Joint Journal
Vol. 103-B, Issue 4 | Pages 689 - 695
1 Apr 2021
Jämsä P Reito A Oksala N Eskelinen A Jämsen E

Aims

To investigate whether chronic kidney disease (CKD) is associated with the risk of all-cause revision or revision due to a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty.

Methods

This retrospective cohort study comprised 18,979 consecutive hip and knee arthroplasties from a single high-volume academic hospital. At a median of 5.6 years (interquartile range (IQR) 3.5 to 8.1), all deaths and revisions were counted. To overcome the competing risk of death, competing risk analysis using the cumulative incidence function (CIF) was applied to analyze the association between different stages of CKD and revisions. Confounding factors such as diabetes and BMI were considered using either a stratified CIF or the Fine and Gray model.


The Bone & Joint Journal
Vol. 103-B, Issue 3 | Pages 589 - 596
1 Mar 2021
Amin N Kraft J Fishlock A White A Holton C Kinsey S Feltbower R James B

Aims

Osteonecrosis (ON) can cause considerable morbidity in young people who undergo treatment for acute lymphoblastic leukaemia (ALL). The aims of this study were to determine the operations undertaken for ON in this population in the UK, along with the timing of these operations and any sequential procedures that are used in different joints. We also explored the outcomes of those patients treated by core decompression (CD), and compared this with conservative management, in both the pre- or post-collapse stages of ON.

Methods

UK treatment centres were contacted to obtain details regarding surgical interventions and long-term outcomes for patients who were treated for ALL and who developed ON in UKALL 2003 (the national leukaemia study which recruited patients aged 1 to 24 years at diagnosis of ALL between 2003 and 2011). Imaging of patients with ON affecting the femoral head was requested and was used to score all lesions, with subsequent imaging used to determine the final grade. Kaplan-Meier failure time plots were used to compare the use of CD with non surgical management.


The Bone & Joint Journal
Vol. 102-B, Issue 11 | Pages 1491 - 1496
1 Nov 2020
Buddhdev PK Vanhegan IS Khan T Hashemi-Nejad A

Aims

Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients.

Methods

Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8).


The Bone & Joint Journal
Vol. 100-B, Issue 7 | Pages 891 - 897
1 Jul 2018
Teeter MG Lanting BA Naudie DD McCalden RW Howard JL MacDonald SJ

Aims

The aim of this study was to determine whether there is a difference in the rate of wear between acetabular components positioned within and outside the ‘safe zones’ of anteversion and inclination angle.

Patients and Methods

We reviewed 100 hips in 94 patients who had undergone primary total hip arthroplasty (THA) at least ten years previously. Patients all had the same type of acetabular component with a bearing couple which consisted of a 28 mm cobalt-chromium head on a highly crosslinked polyethylene (HXLPE) liner. A supine radiostereometric analysis (RSA) examination was carried out which acquired anteroposterior (AP) and lateral paired images. Acetabular component anteversion and inclination angles were measured as well as total femoral head penetration, which was divided by the length of implantation to determine the rate of polyethylene wear.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_6 | Pages 33 - 33
1 Mar 2017
Taheriazam A Safdari F
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Introduction. Despite several studies, controversies prevailed about the rate of complications following one-stage and two-stage bilateral total hip arthroplasty (THA). In current prospective study, we compared the complications and functional outcomes of one-stage and two-stage procedures. Methods. One hundred and eighty patients (ASA class I or II) with bilateral hip osteoarthritis were assigned randomly to two equal groups. Two groups were matched in term of age and sex. All of the surgeries were performed through the Harding approach using uncemented implants. In two-stage procedures, surgeries were performed with 6 months to one year interval. All patients were evaluated one year postoperatively. Results. The Harris hip score averaged 84.1±12.6 and 82.6±15.3 in one-stage and two-stage groups, respectively (p=0.528). The hospital stay was significantly longer in two-stage group (9.8±1.1 versus 4.9±0.8 days). The cumulative hemoglobin drop and number of transfused blood units were the same. One patient in each group developed symptomatic deep venous thrombosis and managed successfully. There was no patient with perioperative death, pulmonary embolism, infection, dislocation, periprosthetic fracture or heterotrophic ossification. No patient required reoperation. Two patients in one-stage group developed unilateral temporary peroneal nerve palsy resolved after 3 and 4 months. Conclusion. The current study showed that one-stage bilateral THA can be used successfully for patients who require bilateral hip arthroplasty without increased rate of complications. The functional and clinical outcomes are comparable and hospital stay is significantly shorter. However, the authors recommend to perform one-stage bilateral THA for healthy patients with ASA class I or II


Bone & Joint 360
Vol. 6, Issue 1 | Pages 34 - 36
1 Feb 2017


The Bone & Joint Journal
Vol. 97-B, Issue 11 | Pages 1512 - 1518
1 Nov 2015
Courtney PM Melnic CM Gutsche J Hume EL Lee G

Older patients with multiple medical co-morbidities are increasingly being offered and undergoing total joint arthroplasty (TJA). These patients are more likely to require intensive care support, following surgery. We prospectively evaluated the need for intensive care admission and intervention in a consecutive series of 738 patients undergoing elective hip and knee arthroplasty procedures. The mean age was 60.6 years (18 to 91; 440 women, 298 men. Risk factors, correlating with the need for critical care intervention, according to published guidelines, were analysed to identify high-risk patients who would benefit from post-operative critical care monitoring. A total of 50 patients (6.7%) in our series required critical care level interventions during their hospital stay. Six independent multivariate clinical predictors were identified (p < 0.001) including a history of congestive heart failure (odds ratio (OR) 24.26, 95% confidence interval (CI) 9.51 to 61.91), estimated blood loss >  1000 mL (OR 17.36, 95% CI 5.36 to 56.19), chronic obstructive pulmonary disease (13.90, 95% CI 4.78 to 40.36), intra-operative use of vasopressors (OR 8.10, 95% CI 3.23 to 20.27), revision hip arthroplasty (OR 2.71, 95% CI 1.04 to 7.04) and body mass index > 35 kg/m2 (OR 2.70, 95% CI 123 to 5.94). The model was then validated against an independent, previously published data set of 1594 consecutive patients. The use of this risk stratification model can be helpful in predicting which high-risk patients would benefit from a higher level of monitoring and care after elective TJA and aid hospitals in allocating precious critical care resources.

Cite this article: Bone Joint J 2015;97-B:1512–18.


The early failure and revision of bimodular primary total hip arthroplasty prostheses requires the identification of the risk factors for material loss and wear at the taper junctions through taper wear analysis. Deviations in taper geometries between revised and pristine modular neck tapers were determined using high resolution tactile measurements. A new algorithm was developed and validated to allow the quantitative analysis of material loss, complementing the standard visual inspection currently used.

The algorithm was applied to a sample of 27 retrievals (in situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate modular prosthesis. The mean wear volumes on the flat distal neck piece taper was 3.35 mm3 (0.55 to 7.57), mainly occurring in a characteristic pattern in areas with high mechanical loading. Wear volume tended to increase with time to revision (r² = 0.423, p = 0.001). Implant and patient specific data (offset, stem size, patient’s mass, age and body mass index) did not correlate with the amount of material loss observed (p >  0.078). Bilaterally revised implants showed higher amounts of combined total material loss and similar wear patterns on both sides. The consistent wear pattern found in this study has not been reported previously, suggesting that the device design and materials are associated with the failure of this prosthesis.

Cite this article: Bone Joint J 2015;97-B:1350–7.


The Bone & Joint Journal
Vol. 97-B, Issue 10 | Pages 1328 - 1337
1 Oct 2015
Briant-Evans TW Lyle N Barbur S Hauptfleisch J Amess R Pearce AR Conn KS Stranks GJ Britton JM

We investigated the changes seen on serial metal artefact reduction magnetic resonance imaging scans (MARS-MRI) of metal-on-metal total hip arthroplasties (MoM THAs). In total 155 THAs, in 35 male and 100 female patients (mean age 70.4 years, 42 to 91), underwent at least two MRI scans at a mean interval of 14.6 months (2.6 to 57.1), at a mean of 48.2 months (3.5 to 93.3) after primary hip surgery. Scans were graded using a modification of the Oxford classification. Progression of disease was defined as an increase in grade or a minimum 10% increase in fluid lesion volume at second scan. A total of 16 hips (30%) initially classified as ‘normal’ developed an abnormality on the second scan. Of those with ‘isolated trochanteric fluid’ 9 (47%) underwent disease progression, as did 7 (58%) of ‘effusions’. A total of 54 (77%) of hips initially classified as showing adverse reactions to metal debris (ARMD) progressed, with higher rates of progression in higher grades. Disease progression was associated with high blood cobalt levels or an irregular pseudocapsule lining at the initial scan. There was no association with changes in functional scores. Adverse reactions to metal debris in MoM THAs may not be as benign as previous reports have suggested. Close radiological follow-up is recommended, particularly in high-risk groups.

Cite this article: Bone Joint J 2015;97-B:1328–37.


The Bone & Joint Journal
Vol. 97-B, Issue 9 | Pages 1197 - 1203
1 Sep 2015
Kim Y Park J Kim J

A number of studies have reported satisfactory results from the isolated revision of an acetabular component. However, many of these studies reported only the short- to intermediate-term results of heterogeneous bearing surfaces in a mixed age group.

We present our experience of using a ceramic-on-ceramic (CoC) bearing for isolated revision of an uncemented acetabular component in 166 patients (187 hips) who were under the age of 50 years at the time of revision. There were 78 men and 88 women with a mean age of 47.4 years (28 to 49). The most common reason for revision was polyethylene wear and acetabular osteolysis in 123 hips (66%), followed by aseptic loosening in 49 hips (26%).

We report the clinical and radiological outcome, complication rate, and survivorship of this group. The mean duration of follow-up was 15.6 years (11 to 19).

The mean pre-operative Harris hip score was 33 points (1 to 58), and improved to a mean of 88 points (51 to 100) at follow-up. The mean pre-operative total Western Ontario and McMaster Universities Osteoarthritis Index score was 63.2 (43 to 91) and improved to 19.8 points (9 to 61) post-operatively. Overall, 153 of 166 patients (92%) were satisfied with their outcome. Kaplan–Meier survivorship analysis, with revision or radiological evidence of implant failure (13 patients, 8%) as end-points, was 92% at 15 years (95% confidence interval 0.89 to 0.97).

Isolated revision of a cementless acetabular component using a CoC bearing gives good results in patients under 50 years of age.

Cite this article: Bone Joint J 2015;97-B:1197–1203.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_18 | Pages 2 - 2
1 Dec 2014
Somasundaram K Awogbadhe M Kavarthapu V Li P
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Osteonecrosis of femoral head is well known and recognised complication in Sickle cell disease patients. Due to the severity of the Osteonecrosis, hip pain is major limiting factor for these patients requiring total hip arthroplasty in relatively young age. We studied and report our results in total hip arthroplasty of sickle cell patients. We studied 80 patients from our combined Orthopaedic & Haematology Sickle cell clinic. Twenty four patients had painful Osteonecrosis with secondary osteoarthritis of hip and underwent total hip arthroplasty. Three patients had bilateral hip replacements. A total of twenty seven replacements were studied retrospectively. 19 patients had uncemented (Corail/Pinnacle), 5 patients had hybrid(Pinnacle/Exeter) and 3 patients had cemented(Exeter) total hip arthroplasties respectively. The patients were serially followed up for clinical and radiological assessments for loosening. Oxford hip score (OHS) was used to assess the functional outcome. The average age of the patients at the time of surgery was 38.4 (Range – 20 to 59 years. The average follow up was 5.1 years (Range – 6 months to 10 years). There were 13 female and 11 male patients. The average oxford hip score was 38.07 with 10% infection rate and 11% aseptic loosening. Arthroplasties carry high risk in patients with sickle cell disease. We report lower rates of infection and loosening rates compared to the earlier studies. Combined Haematological and Orthopaedic team input is optimal during assessment, surgery, peri-operative period and follow up. Our results of total hip replacements in sickle cell disease patients are good


Bone & Joint 360
Vol. 3, Issue 6 | Pages 10 - 12
1 Dec 2014

The December 2014 Hip & Pelvis Roundup360 looks at: Sports and total hips; topical tranexamic acid and blood conservation in hip replacement; blind spots and biases in hip research; no recurrence in cam lesions at two years; to drain or not to drain?; sonication and diagnosis of implant associated infection; and biomarkers and periprosthetic infection


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 130 - 130
1 Dec 2013
Morapudi S
Full Access

Introduction:. The clinical significance of serum metal ion levels alone in patients with stemmed MoM hip arthroplasty remains uncertain. This study aims to measure the metal ion levels in patients with unilateral and bilateral hip arthroplasty to see whether or not the patients with bilateral hips have higher metal ions. Patients and Methods. All the patients with bilateral MoM hip arthroplasty were identified from the research database. These patients were then matched with those in a similar age group who had a unilateral hip arthroplasty, but same University of California Los Angeles (UCLA) activity score. The UCLA activity scores along with other hip scores have been previously gathered for all the patients. Both sets of patients then had measurement of serum cobalt and chromium levels. The results were analyzed and compared. Results:. There were a total of 53 patients with bilateral hips and 53 matched patients with unilateral hips. The average serum Cobalt and Chromium levels were 34 nmol/L (range <10–76) and 23 nmol/L (range <10–104) respectively in the bilateral group; and 14 nmol/L (range <10–45) and 21 nmol/L (range <10–57) in the unilateral group. Given that the MHRA (UK) threshold levels deemed clinically significant are 120 nmol/L and 135 nmol/L for Cobalt and Chromium respectively; the results obtained here are not clinically significant. Conclusions:. One would normally expect, with mathematical reasoning, a patient with bilateral hip arthroplasty to have higher serum metal ion levels than a patient with unilateral arthroplasty. However, this study goes to show that it is not the case


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 290 - 290
1 Dec 2013
Burgett M Donaldson T Clarke I
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In an effort to understand the role of metal ion analysis and how it relates to revision surgery and implant wear, four revised MOM cases were reviewed. The first case was revised for acute infection and is representative of the low bearing wear predicted by MOM simulator studies. Two of the four cases had apparent anterior subluxation as a result of hip hyperextension occurring with long stride gaits. The last case is a true hypersensitivity response to CoCr ions. All four MOM prostheses were implanted by one surgeon and revised by the same surgeon approximately 6–8 years postoperatively. The implants had been positioned satisfactorily with inclination angles 45°–55° and anteversion angles 28°–42°. Patient A (76 y/o female) with bilateral MOM hip replacements, was revised at approximately 8 years due to infection and had moderately elevated ions at the time of revision surgery (Co = 5, Cr = 2.3, Ti = 4). Only the femoral head was retrieved in this case. Retrieval analysis identified a well defined main-wear zone and one polar stripe. The CMM indicated there was minimal wear overall (form factor = 11 μm). Patient B (33 y/o male) with bilateral MOM hip replacements, was revised at approximately 8 years due to pain, popping/catching sensations, and elevated ions (Co = 33, Cr = 17, Ti = 90). Intraoperatively, the implant was observed subluxing superiorly from the acetabular cup with anterior rotation of the leg. Both the femoral head and acetabular cup were retrieved. Retrieval analysis identified a well defined main-wear zone and multi-directional polar stripe formations similar to those reported on dislocated implants (Figure 1)[McPherson 2012, 2013]. The CMM indicated that overall wear was significant (form factor > 100 μm). Patient C (77 y/o female) was revised at approximately 6 years due to pain, suspected implant loosening, osteolytic cysts determined by CT, and highly elevated ions (co = 164, Cr = 45, Ti = 33). Intraoperatively, there was evidence of wear including darkly stained tissue and osteolytic cysts. Both the femoral head and acetabular cup were retrieved. Retrieval analysis identified a well defined main-wear zone and one polar stripe. CMM indicated considerable wear (head form factor > 200, cup form factor >300). Patient D (45 y/o female) was revised at approximately 6 years due to pain, apparent reactive response joint effusion, and moderately elevated ions (Co = 5, Cr = 6, Ti = 71). Only the femoral head was retrieved. Retrieval analysis identified a well defined main-wear zone and one polar stripe. Minimal wear was indicated by CMM (form factor = 21). These four cases demonstrate distinct failure models of MOM hips and their respective metal ion results. Due to the diversity of patient location, a variety of clinical labs were utilized for this patient population. Caution should be used in interpreting metal ion analysis, as there are still no standards. Figure 1: Retrieval analysis of stripe wear identified on femoral head from patient B. Figure 2: Femoral head from patient C showing broader polar stripe associated with anterior subluxation in comparison to narrow polar stripe found on femoral head from patient A


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 436 - 436
1 Sep 2012
Aarvold A Smith J Tayton E Jones A Briscoe A Lanham S Dunlop D Oreffo R
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Background. Skeletal stem cells (SSCs) have been used for the treatment of osteonecrosis of the femoral head to prevent subsequent collapse. In isolation SSCs do not provide structural support but an innovative case series in Southampton, UK, has used SSCs in combination with impaction bone grafting (IBG) to improve both the biological and mechanical environment and to regenerate new bone at the necrotic site. Aims. Analysis of retrieved tissue-engineered bone as part of ongoing follow-up of this translational case series. Methods. With Proof-of-Concept established in vitro and in vivo, the use of a living bone composite of SSCs and allograft has been translated to four patients (five hips) for treatment of osteonecrosis of their femoral heads. Parallel in vitro culture of the implanted cell-graft construct was performed. Patient follow-up was by serial clinical and radiological examination. In one patient collapse occurred in both hips due to more advanced disease than was originally appreciated. This necessitated bilateral hip arthroplasty, but allowed retrieval of the femoral heads. These were analyzed for Type 1 Collagen production, bone morphology, bone density and mechanical strength by micro computed tomography (CT), histology (A/S stain, Collagen Type 1 immunostain, biorefringence) and mechanical testing. Representative sections of cortical, trabecular and tissue engineered bone were excised from the femoral heads using a diamond-tipped saw-blade and tested to failure by axial compression. Results. Parallel in vitro analysis demonstrated sustained cell growth and viability on the allograft. Three patients currently remain asymptomatic at up to three year follow-up. Histological analysis of the two retrieved femoral heads demonstrated, critically, Type 1 collagen production in the regenerated tissue as well as mature trabecular architecture, indicative of de novo tissue engineered bone. The trabecular morphology of regenerated bone was evident on CT, and this had a bone density of 1400 Grey scale units, (compared to 1200 for natural trabecular bone and 1800 for cortical bone). On axial compressive testing the regenerated bone on the left showed a 24.8% increase in compressive strength compared to ipsilateral normal trabecular bone, and a 22.9% increase on the left. Conclusions. Retrieval analysis data has demonstrated the translational potential of a living bone composite, while ongoing clinical follow-up shows this to be an effective new treatment for osteonecrosis of the femoral head. Regeneration of the necrotic bone may prevent subsequent collapse, thereby delaying, or possibly avoiding, the need for hip arthroplasty in early stage osteonecrosis. Evaluation of this tissue engineering construct has confirmed the potential for clinical treatment of bone defects using SSC based strategies


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVI | Pages 117 - 117
1 Aug 2012
Aarvold A Smith J Tayton E Jones A Dawson J Briscoe A Lanham S Dunlop D Oreffo R
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Background. Skeletal stem cells can be combined with human allograft, and impacted to produce a mechanically stable living bone composite. This strategy has been used for the treatment of femoral head avascular necrosis, and has been translated to four patients, of which three remain asymptomatic at up to three year follow-up. In one patient collapse occurred in both hips due to widely distributed and advanced AVN disease, necessitating bilateral hip arthroplasty. However this has provided the opportunity to retrieve the femoral heads and analyse human tissue engineered bone. Aims. Analysis of retrieved human tissue-engineered bone in conjunction with clinical follow-up of this translational case series. Methods. A parallel in vitro culture of the implanted cell-graft constructs was set up at the time of surgery, with serial cell viability stains performed up to six weeks. Patient follow-up was by serial clinical and radiological examination. Tissue engineered bone from the two retrieved femoral heads was analysed histologically by Alcian blue & Sirius red stain and bi-refringence, by micro computed tomography (microCT) for both bone density and morphology, and by compression testing for mechanical strength. Normal trabecular and cortical bone from the femoral heads was used as controls. Results. Parallel in vitro analysis demonstrated sustained cell growth and viability on the allograft. Histologically, the retrieved tissue engineered specimens demonstrated a mature trabecular micro-architecture and organization identical to normal trabecular bone. MicroCT revealed trabecular morphology within the tissue-engineered bone, with bone density of 1400 Grey scale units (compared to 1200 for natural trabecular bone and 1800 for cortical bone). Axial compression testing showed no difference in strength between engineered and trabecular bone. Conclusions. Widespread residual necrosis in the femoral heads of one patient resulted in collapse requiring hip arthroplasty, but analysis of the tissue engineered bone sections has demonstrated the translational potential of a living bone composite to restore both the biological and mechanical characteristics of bone defects. Clinical follow-up shows this to be an effective new treatment for focal early stage avascular necrosis of the femoral head, and this unique retrieval analysis data confirms the potential of cell-based strategies for clinical treatment of bone defects