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Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_14 | Pages 20 - 20
1 Nov 2021
Shimmin A Dhawan R Madurawe C Pierrepont J Baré J
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Adverse spinopelvic mobility (SPM) has been shown to increase risk of dislocation of primary total hip arthroplasty (THA). In patients undergoing THA, prevalence of adverse SPM has been shown to be as high as 41%. Stiff lumbar spine, large posterior standing pelvic tilt and severe sagittal spinal deformity have been identified as risk factors for increased hip instability. Dislocation rates for dual mobility articulations have been reported to be 0% to 1.1%. The aim of this study was to determine the early survivorship from the Australian National Joint Replacement Registry (AOANJRR) of patients with adverse SPM who received a dual mobility articulation.

A multicentre study was performed using data from 229 patients undergoing primary THA, enrolled consecutively. All the patients who had one or more adverse spine or pelvic mobility parameters had a dual mobility articulation inserted at the time of their surgery. Average age was 76 (22 to 93) years and 63% were female. At a mean of 2.1 (1 – 3.3) years post-op, the AOANJRR was analysed for follow-up. Reasons for revision and types of revision were identified.

The AOANJRR reported two revisions. One due to infection and the second due to femoral component loosening. No revisions for dislocation were reported. One patient died with the prosthesis in situ. Kaplan Meier survival was 99.3% (CI 98.3% − 100%) at 2 years.

DM bearings reduce the risk of dislocation of primary THA in patients with adverse spine and pelvic mobility.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_16 | Pages 7 - 7
1 Oct 2017
Dhawan R Blong J Youssef B Lim J
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The aim of this study was to assess the incidence, management and survival of unstable pelvic ring injuries in patient aged 65 years or older.

Prospectively kept data was analysed from April 2008 to October 2016. Information regarding the mechanism, fracture type, associated injuries, treatment and complications of the treatment were collected. Annual incidence was calculated and a Kaplan Meier survival analysis for carried out at 30 days, 1 year and 5 years.

404 patient records were available. 125 were 65 years or older (60 males and 65 females). 24 (19%) patients required surgical stabilisation to permit mobilisation the remaining 101 patients, treated conservatively were mobilised with immediate weight-bearing under the supervision of a physical therapist with assistive devices. Mean age was 73.5 years (SD 9.9 yrs). Fracture types were − 61.B2 47(37.6%), 61.B1 24(32%), 61.A2 17(13.6%), 61.C1 16(12.8%), 61.C2 5(4%), 61.A1 2(1.6%) and 61.C3 3(2.4%). Mechanisms of injury included fall from standing height − 41 (32%), road traffic collisions − 46(36.8%), fall from higher than standing height − 10(8%), fall from horse − 6(4.8%), jumped from bridge − 3(2.4%) & others 19(15%). Complications in surgical group included 1 death from PE and 1 wound infection treated with vacuum assisted dressing. Survivorship was 91.7%(30 days), 82.5%(1 year) and 49.7%(5 years).

Most common fracture type is 61.B2. Over one third of fractures resulted from low energy mechanism. The majority 81% could be managed conservatively. One-year survival figure closely resembles the fracture neck of femur group, highlighting the frailty of this population.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 184 - 184
1 Sep 2012
Dhawan R Sharma V
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Aims

The aim of this study was to statistically analyse the incidence and distribution of humerus fractures in the adult age group between 3rd and 10th decades.

Methods

The total number of patients was retrieved from the audit department of the hospital using the codes to identify patients between 1997 and 2009. The data included total number of patients aged 20 to 100 years who were either reviewed in the fracture clinics or admitted to the hospital with forearm fractures along with patient gender, age at the time of incident and time of the year the incident occurred. Annual incidence of fractures along with the distribution of fracture incidence per year and per individual month was calculated. The patients’ age were classified in to 3rd to 10th decades. Linear regression analysis was carried out to identify the relationship between fracture incidence and the age or time of the injury. Correlation coefficients(R) and r2 were calculated for all the regression analyses. SPSS (version 16) and Microsoft Excel 2007 were used for statistics.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 469 - 469
1 Sep 2012
Dhawan R Sharma V
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Aims

The aim of this study was to statistically analyse the incidence and distribution of forearm fractures in the adult age group (3rd–10th Decades) between 1997 and 2009.

Methods

Records of patients with forearm fractures were retrieved from the hospital audit department using the predetermined codes to identify patients. The data included total number of patients between 20 and 100 years who were either reviewed in the fracture clinics or admitted to the hospital with forearm fractures along with patient gender, age at the time of incident and time of the year the incident occurred. Incidence of total fractures per year and per each month in the year was calculated. The patients were divided into age groups between 2nd to 10th decades. Linear regression analysis was carried out to identify the relationship between fracture incidence and the age or time of the injury. Correlation coefficients(R) and r2 were calculated for all the regression analyses. Fractures were also classified according to the Orthopaedic Trauma Association (OTA) classification system. SPSS (version 16) and Microsoft Excel 2007 were used for statistics.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 484 - 484
1 Sep 2012
Sharma V Dhawan R
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Aims and objectives

The aim of this study was to assess the radiographic outcome by using Lindstrom grading for the management of Malone 2A and 2B fractures by 3 different methods of treatment. The three different methods included manipulation under anaesthesia, k-wire fixation and open reduction internal fixation.

Methods and materials

Between March 2006 and February 2007, 62 intra-articular distal radius fractures were retrospectively selected. 31 patients including 21 females and 9 males with an average age of 62 years were classified as Malone 2A fractures and 32 patients including 18 females and 14 males with an average age of 64.5 years were classified as Malone 2B fractures. 18 patients had manipulation under anaesthetic (MUA) and immobilisation in a plaster of paris (POP) cast, 27 patients had manipulation and k-wire fixation and 17 patients had open reduction internal fixation (ORIF) of the fractures. All the patients had radiographic assessment at 6 weeks post op using Lindstrom grading. Grade 1 and 2 were considered acceptable, grade 3 and 4 were considered unacceptable.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 485 - 485
1 Sep 2012
Dhawan R Sharma V
Full Access

Aims and objectives

The aim of this study was to statistically analyse the calcaneal fractures occurring in the community and distribution within the various age groups divided into decades.

Methods and materials

Records of calcaneal fractures were retrieved from the audit department of the hospital using the various codes to identify patients reviewed in the clinics or admitted to the hospital between 1997 and 2009. The data collected included the total number of calcaneal fractures, total number in either gender, age at the time of incident, month of the year the incident occurred. Annual distribution of incidence of forearm fractures was calculated for every year and every month of the year. The age of the patients was divided into decades. Linear regression analysis and correlation coefficients were calculated between the incidence of fractures and different variables including age, gender and the time of the injury.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 190 - 190
1 May 2011
Dhawan R Hashemi-Nejad A Eastwood D
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Introduction: Avascular necrosis (AVN) is a serious complication affecting the femoral head following an unstable slipped capital femoral epiphysis (SCFE) particularly if the slip is severe. The incidence of AVN may be as high as 47%.

Purpose: To determine whether or not the avascular insult associated with a massive unstable SCFE is a temporary event and whether this may resolve in the second week post injury.

Methods: 6 patients (4 male:2 females), mean age 14.9 yrs (13.2–17.5yrs) with acute severe unstable SCFE were reviewed. The mean Southwick slip angle was 51.20 deg (40.1 – 66.60). 5 of 6 cases were severe. All cases underwent a subcapital cuneiform femoral neck osteotomy at a mean 14 days (7–24 days) after the acute event. Pre-operatively, the hip/limb was rested in ‘slings and springs’. No hip underwent a manipulative procedure. All hips underwent an MRI scan at a mean 8.6 days post injury (range 4–15 days) to determine the viability of the femoral head.

Results: In all 6 cases, the femoral head was reported to be viable. All femoral heads showed signs of bone oedema and other features indicative of a blood supply.

Following the cuneiform osteotomy, patients were mobilized partial weight bearing for 8 weeks. At a mean 12 month follow up, radiographs confirmed that all oste-otomies had united and no hip showed evidence of AVN.

Conclusion: If the acute severe unstable slip is associated with an avascular insult to the femoral head, this may be a temporary phenomenon and assuming the hip is not subjected to any immediate secondary trauma such as operative reduction, then there may be a spontaneous recovery in the blood supply as evidenced by the viable femoral head seen on MRI.

Significance: Our study suggests that there may be a time period during which the slipped femoral head may be vulnerable to a second insult and hence AVN. The timing of any surgical intervention designed at reducing the slip should take this into account and be performed carefully to ensure that the blood vessels on the posterior aspect of the femoral neck are not disrupted. When the presentation of an acute unstable and severe SCFE is delayed beyond 24 hours, we favour delaying subsequent operative correction for a further 2–3 weeks to maximize the chance of a viable femoral head.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 133 - 133
1 May 2011
Dhawan R Pendegrass C Blunn G
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Introduction: Hydrogenated (acetylene:C2H2) and silanized (tetra methyl silane:TMS) diamond-like-carbon coatings (DLC) are applied to titanium alloy to reduce surface energy, cell adhesion and hydrophilicity. The incorporation of silicon into DLC reduces its surface energy. It was hypothesized that surfaces that have high surface energy and high hydrophilicity favoured the adhesion and maturation of fibroblasts when compared with C2H2 and TMS coated substrates in vitro. This would help in achieving a seal at the prosthesis – soft tissue interface, thereby helping in reducing infection.

Methods: and Materials: Fibroblasts were cultured on 10 mm diameter titanium alloy, C2H2 and TMS coated titanium alloy discs for 4 hours and 24 hours (2500 cells per disc). Cell area, adhesion plaque numbers, number of plaques per unit area (plaque density) and the total area of adhesion plaques per cell were analysed. The results were compared between experimental groups and controls at 4 and 24 hours. In order to measure the strength of adhesion of cells fibroblasts were cultured on discs (30 mm diameter)[machine finished and polished(Ra = 0.031)](density-300,000 cells per disc) for 4 and 24 hours with similar coatings and exposed to radial shear by flow (100 mls/min) of culture media over their surface. These discs were then stained and analysed using Photoshop (ver.5.5) and SPSS (ver.16). Mann-Whitney tests were used to calculate significance (p< 0.05).

Results: At 4 and 24 hours, the number of adhesion plaques was significantly greater on control and C2H2 compared with TMS. At 4 hours, cell area on control discs was significantly greater than C2H2 and TMS. At 24 hours, cell area on control and C2H2 was significantly greater than TMS. Between 4 and 24 hours, the number of adhesion plaques increased significantly on all the surfaces. Cell area increased significantly on C2H2 and TMS between 4 and 24 hours. At 4 hours, shear stress needed to dislodge the cells was highest for polished C2H2 and least for titanium unpolished surface. Cells on polished surfaces in corresponding groups required higher shear stress to remove the cells than cells on unpolished surfaces. At 24 hours, cells on polished C2H2 required significantly higher shear stresses to detach them than cells on unpolished C2H2 and TMS (polished and unpolished). Cells on unpolished Ti required higher stress to dislodge than cells on unpolished TMS. From 4 to 24 hours, a significant increase in shear stress to remove the cells was required on all unpolished surfaces and polished C2H2. A significant correlation was seen between adhesion plaque density at 4 hours and shear stress.

Discussion: This work supports the hypothesis that surfaces with high surface energy and high hydrophilicity lead to increased cell attachment and cell area. It also shows the correlation between adhesion plaque density and the shear stress needed to dislodge fibroblasts from bioactive surfaces.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 615 - 616
1 Oct 2010
Dhawan R Blunn G Pendegrass C
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Introduction: Due to uneven distribution of stress between the stump and the socket in amputees pain, infection and necrosis of soft tissue can be problematic (Dudek, Marks, & Marshall 2006)Implants have been developed that allow the external prostheses to attach directly to the skeleton by a percutaneous section by osseointegration that reduces the stresses on the soft tissue alleviating the problems associated with a socket (Lai et al. 1998). It has been postulated that surface coatings can enhance soft tissue attachment and increase the in growth of fibroblastic dermal tissues enhancing the seal at the skin implant interface and reducing infection (Pendegrass et al. 2006). Hydrogenated (acetylene: C2H2) and silanized (tetra methyl silane: TMS) diamond-like-carbon coating (DLC) can be applied to titanium(Ti) alloy to reduce surface energy and hydrophilicity. It was hypothesized that biomaterial surfaces having high surface energy and high hydrophilicity eg, Ti alloy enhance the adhesion and maturation of human dermal fibroblasts when compared with C2H2 and TMS coated substrates in vitro.

Methods: Fibroblasts were cultured on 10 mm diameter Ti alloy, C2H2 and TMS coated Ti alloy discs for 4 hours and 24 hours (2500 cells per disc). Cell area and attachment were analysed using Image Analysis and quantification of immunolocalised vinculin containing adhesion plaques respectively. The number of plaques per cell and cell area were compared between experimental groups and controls at 4 and 24 hours. The change in cell area and number of adhesion plaques between 4 and 24 hours were compared for each substrate type. SPSS version 10 was used for the statistical analysis.

Results: At 4 and 24 hours, the number of adhesion plaques was significantly greater on control and C2H2 compared with TMS (p< 0.001). No significant difference was observed between control and C2H2 discs (p> 0.05). At 4 hours, cell area was significantly greater in control compared to both C2H2 and TMS (p< 0.001). At 4 hours, the cell area in TMS was significantly greater than C2H2 (p< .001). At 24 hours, the cell area on control and C2H2 was significantly greater than TMS(p< 0.001). However, there was no significant difference between cell area on control and C2H2 (p> 0.05). From 4 to 24 hours, the number of adhesion plaques increased significantly on all the surfaces (p< 0.001). Cell area increased significantly on C2H2 and TMS between 4 and 24 hours. No significant increase in the cell area was observed on control substrates

Discussion: This supports the hypothesis that surfaces with high surface energy and high hydrophilicity lead to increased cell attachment and cell area. Thus, it can be concluded that the hydrophilic surfaces with higher surface energies favour the adhesion of dermal fibroblasts.