Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis

Background and purpose - Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of pri- mary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time.Methods - A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postop- eratively and at follow-up.Results - The meta-analysis determined that peri- acetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex.Conclusion - Peri-acetabular BMD decreases at differ- ent rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cor- tical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.Orthopaedics, Trauma Surgery and Rehabilitatio

A new approach to surgical management of tibial plateau fractures

Tibial plateau fractures (TPFs) are challenging, requiring complex open reduction and internal fixation (ORIF) and are often associated with complications including surgical site infections (SSIs). In 2007, we introduced a novel management protocol to treat TPFs which consisted of an angiosome- or perforator-sparing (APS) anterolateral approach followed by unrestricted weight bearing and range of motion. The primary aim of this retrospective study was to investigate complication rates and patient outcomes associated with our new management protocol. In total, 79 TPFs treated between 2004 and 2007 through a classic anterolateral surgical approach formed the "Classic Group"; while 66 TPFS treated between 2007 and 2013 formed the "APS Group". Fracture reduction, maintenance of reduction and patient-reported outcomes were assessed. There was a clinically important improvement in the infection incidence with the APS (1.5%) versus the Classic technique (7.6%) (1/66 versus 2/79 for superficial infections; 0/66 versus 4/79 for deep infections). Despite a more aggressive rehabilitation, there was no difference in the fracture reduction over time or the functional outcomes between both groups (p > 0.05). The APS anterolateral approach improved the rate of SSIs after TPFs without compromising fracture reduction and stabilisation. We continue to use this new management approach and early unrestricted weight bearing when treating amenable TPFs.Stuart A. Callary, Claire F. Jones, Karim Kantar ... Markus P. Baker, Dominic Thewlis, Gerald J. Atkins ... et al

Highly porous tantalum acetabular components without ancillary screws have similar migration to porous titanium acetabular components with screws at 2 years: a randomized controlled trial

Background: It is proposed that highly porous coatings on acetabular components, such as a porous tantalum coating, provide adequate fixation without ancillary screw fixation in primary total hip arthroplasty (THA). However, tantalum acetabular components have been associated with higher rates of revision than other uncemented components in national registries. The aim of this randomized controlled trial is to determine whether the early migration of a solid-backed tantalum acetabular component was no greater than that of a titanium acetabular component with ancillary screw fixation that has proven good clinical results. Methods: Sixty-six patients aged 40 to 64 years, with osteoarthritis and Charnley grade A or B activity grade and who underwent primary THA, were recruited into the trial. Patients were randomized intraoperatively to receive either the tantalum or titanium acetabular component. All patients received the same cemented polished tapered femoral stem, 28-mm cobalt-chromium femoral head, and highly cross-linked polyethylene liner. Acetabular component migration was measured using radiostereometric analysis at 4-6 days postoperatively and at 6 weeks, 3 months, 1 and 2 years following THA. Results: The mean proximal migration at 2 years for the tantalum cohort was 0.17 mm (95% confidence interval, 0.09-0.24) which was no greater than that of the titanium cohort which was 0.19 mm (0.07-0.32). Harris hip scores and functional activity scores were similar between groups. Conclusion: These results demonstrate that early stability can be achieved without ancillary screw fixation through the use of a highly porous high friction coating on a solid-backed modular acetabular component. Level of Evidence: Level I.Donald W. Howie, Oksana T. Holubowycz, Stuart A. Callary, Thomas S. Robertson, Lucian B. Solomo

Long Cephalomedullary Nails Can Be a Cheap and Effective Interval Revision Prosthesis in Infected Hip Replacements That Require Proximal Femoral Replacement: A Small Case Series

Hip prosthetic joint infection management is complex and expensive, especially in severe bone loss. Reducing the price of interval prosthesis when performing staged revision could minimize costs without compromising outcomes. We present 2 similar techniques developed independently that use an antibiotic-coated cephalomedullary nail with a total hip arthroplasty bearing (head and cemented acetabular component) attached to it as an interval proximal femoral replacement prosthesis. Using this technique, the femoral implant cost was reduced up to 10-fold. All patients have recovered well with resolution of infection and functional recovery similar to patients undergoing proximal femoral replacement. In one case, the lag screw (femoral neck) fractured at 5 months prompting the second-stage revision. This complication should be considered when deciding the timing of second-stage revisions in these cases.Boopalan Ramasamy, Aaron Scott Hammat, Renjy Nelson, Stuart Adam Callary, Ping Keung Chan, Lucian Bogdan Solomo

Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis

Background and purpose — Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of primary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time. Methods — A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postoperatively and at follow-up. Results — The meta-analysis determined that periacetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex. Conclusion — Peri-acetabular BMD decreases at different rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cortical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.Thomas S Robertson, Bart G Pijls, Zachary Munn, L Bogdan Solomon, Rob G H H Nelissen, and Stuart A Callar

Does cup-cage reconstruction with oversized cups provide initial stability in THA for osteoporotic acetabular fractures?

Background The incidence of acetabular fractures in osteoporotic patients is increasing. Immediate total hip arthroplasty (THA) has potential advantages, but achieving acetabular component stability is challenging and, at early followup, reported revision rates for loosening are high. Questions/purposes This study measured acetabular component stability and the initial surface contact achieved between the acetabular component and unfractured region of the pelvis after THA using an oversized acetabular component and cup-cage reconstruction. Methods Between November 2011 and November 2013, we treated 40 acute acetabular fractures in patients older than 70 years of age. Of these, 12 (30%) underwent immediate THA using an oversized acetabular component with screws inserted only into the ilium and a cup-cage construct. Postoperatively all patients were mobilized without weightbearing restrictions. Indications for immediate THA after acetabular fractures were displaced articular comminution deemed unreducible. Eleven of the 12 were prospectively studied to evaluate the initial stability of the reconstructions using radiostereometric analysis. One of the patients died of a pulmonary embolism after surgery, and the remaining 10 (median age, 81 years; range, 72–86 years) were studied. Of these, five were analyzed at 1 year and five were analyzed at 2 years. Acetabular component migration was defined as acceptable if less than the limits for primary THA that predict later loosening (1.76 mm of proximal migration and 2.53 of sagittal rotation). The contact surface between the acetabular component and ilium in direct continuity with the sacroiliac joint, and the ischium and pubis in direct continuity with the symphysis pubis, was measured on postoperative CT scans. Results At 1 year the median proximal migration was 0.83 mm (range, 0.09–5.13 mm) and sagittal rotation was 1.3° (range, 0.1°–7.4°). Three of the 10 components had migration above the suggested limits for primary THA at 1 year postoperatively. The contact surface achieved at surgery between the acetabular component and pelvis ranged from 11 to 17 cm2 (15%–27% of each component). Conclusions The majority of acetabular components in this cohort were stable despite the small contact surface achieved between the component and pelvic bone. Three of 10 migrated in excess of the limits that predict later loosening in primary THA but it remains to be seen whether these limits apply to this selected group of frail osteoporotic patients. We continue to use this technique routinely to treat patients with the same indications, but since the analysis of these data we have added screw fixation of the acetabular component to the ischial tuberosity and the superior pubic ramus. Level of Evidence Level IV, therapeutic study.Lucian B. Solomon, Patrick Studer, John M. Abrahams, Stuart A. Callary, Caroline R. Moran, Roumen B. Stamenkov, Donald W. Howi

The variation in hip stability measurements between supine and standing radiographs of dysplastic hips

AIMS: The aims of this study were to compare clinically relevant measurements of hip dysplasia on radiographs taken in the supine and standing position, and to compare Hip2Norm software and Picture Archiving and Communication System (PACS)-derived digital radiological measurements. METHODS: Preoperative supine and standing radiographs of 36 consecutive patients (43 hips) who underwent periacetabular osteotomy surgery were retrospectively analyzed from a single-centre, two-surgeon cohort. Anterior coverage (AC), posterior coverage (PC), lateral centre-edge angle (LCEA), acetabular inclination (AI), sharp angle (SA), pelvic tilt (PT), retroversion index (RI), femoroepiphyseal acetabular roof (FEAR) index, femoroepiphyseal horizontal angle (FEHA), leg length discrepancy (LLD), and pelvic obliquity (PO) were analyzed using both Hip2Norm software and PACS-derived measurements where applicable. RESULTS: Analysis of supine and standing radiographs resulted in significant variation for measurements of PT (p < 0.001) and AC (p = 0.005). The variation in PT correlated with the variation in AC in a limited number of patients (R2 = 0.378; p = 0.012). CONCLUSION: The significant variation in PT and AC between supine and standing radiographs suggests that it may benefit surgeons to have both radiographs when planning surgical correction of hip dysplasia. We also recommend using PACS-derived measurements of AI and SA due to the poor interobserver error on Hip2Norm.Ameya Bhanushali, Mukai Chimutengwende-Gordon, Martin Beck, Stuart Adam Callary, Kerry Costi, Donald W. Howie, Lucian Bogdan Solomo