Evidence Of Subsidence Research Articles

3D-printed titanium alloy cage in anterior and lateral lumbar interbody fusion for degenerative lumbar spine disease.

The most commonly used cages for intervertebral disc replacement in lumbar fusion procedures are made predominantly from polyetheretherketone (PEEK). There is sufficient data studying their subsidence and failure rates from a variety of approaches. A novel implant is now available for commercial use, 3D-printed porous titanium (3DppTi) alloy cages, which have recently become available for use in spinal procedures. They have been shown in ovine models to have superior efficacy and fusion rates compared to traditional cages. However, there is limited data on their use in clinical practice and long-term outcomes associated with them. A retrospective chart review was performed, of all patients in a single institution who underwent lumbar spine fusion surgery via an anterior or lateral approach with a 3D-printed titanium alloy cage, between January 2020 and February 2021. Clinic letters, imaging and operation reports were independently reviewed to assess for fusion, or evidence of subsidence on follow-up. Fifty patients were identified as meeting inclusion criteria, with a total of 66 operative levels. Of these operative levels, 32 were via an anterior approach and 34 via a lateral approach. One patient demonstrated a Marchi grade 0 subsidence, with recurrence of radiculopathy 2 months after an anterior approach, requiring posterior decompression and stabilization. A second patient demonstrated a Marchi grade 1 subsidence after a lateral approach, but did not require further surgery as they were asymptomatic at 2 years of follow-up. This study demonstrated an overall subsidence rate of 3.03%. There was a median follow-up time of 11.3 months for all patients. 3D-printed titanium alloy cages demonstrate a lower subsidence rate compared to historically published rates for alternative intervertebral cages, in anterior and lateral lumbar spine fusion surgery.

Midterm Survivorship and Complications of the Cadence Total Ankle Arthroplasty

Category: Ankle Arthritis; Ankle Introduction/Purpose: The Cadence total ankle arthroplasty (TAA) system first entered clinical use in 2016. Short-term outcomes with a minimum of two-year follow-up time have demonstrated survivorship between 93.7% and 100% with improvements in patient-reported outcomes measures, coronal alignment, and range of motion1–4. The purpose of this study is to report the midterm survivorship and complications of Cadence TAA patients with a minimum of 4.5-year radiographic follow-up. Methods: A retrospective chart review was conducted to identify a total of 22 TAA patients with the Cadence implant and a minimum follow-up time of 4.5-years. Patient age, sex, body mass index, diabetes mellitus status, rheumatoid arthritis status, smoking status, laterality, and diagnosis for TAA were collected from patient chart reviews. Preoperative FAAM-ADL subscore, FAAM-Sport subscore, and VAS pain scores and the postoperative scores at the last follow-up visit was also collected. 13 out of 22 patients had preoperative FAAM-VAS scores available while 10 out of 22 patients had postoperative FAAM-VAS scores available. Postoperative complications in the form of wound-related issues and those requiring reoperation or revision were noted, with revision defined as removal or exchange of metal component. 5-view radiographs obtained preoperatively and at the last follow-up visit were used to measure coronal alignment, range of motion, evidence of subsidence or loosening, and osteolysis as previously described1. Results: 3 out of 22 patients required a revision surgery, 1 for loosening of tibial component and 2 for infection. 4 out of 22 patients underwent a reoperation, 2 for gutter debridement due to impingement or heterotopic ossification, 1 for periprosthetic medial malleolar fracture, and 1 for removal of painful medial malleolar screws. The average FAAM-ADL, FAAM-Sport, and VAS pain scores improved from 50.6, 26.5, and 59.9 to 69.5, 35.5, and 23.6, respectively. The coronal alignment angle decreased from 5.96 degrees from neutral to 2.31 degrees. The average dorsiflexion and plantarflexion angles were 14.74 and 17.18 degrees, respectively, for an average range of motion of 31.9 degrees. 3 out of 22 patients had evidence of osteolysis while no patients had evidence of loosening or subsidence. Conclusion: The midterm survivorship of Cadence TAA system in 22 patients was 86.4%. Excluding the two cases of infection which are typically not attributed to implant performance, the survivorship was 95.4%. The reasons for reoperation included impingement, heterotopic ossification, periprosthetic fracture, and removal of painful hardware. The average FAAM-ADL, FAAM- Sport, VAS pain scores and coronal alignment improved. Analysis of longer follow-up time in greater patient cohorts is necessary for clearer understanding of this fixed-bearing implant’s performance.

Primary Arthroplasty for Unstable and Failed Intertrochanteric Fractures: Role of Multi-Planar Trochanteric Wiring Technique.

The primary objective of the current study is to demonstrate the trochanteric wiring technique. A secondary objective is to evaluate the clinico-radiological outcomes of use of the wiring technique during primary arthroplasty for treatment of unstable and failed intertrochanteric fractures. A prospective study including follow-up of 127 patients with unstable and failed intertrochanteric fractures who underwent primary hip arthroplasty using novel multi-planar trochanteric wiring was conducted. The average follow-up period was 17.8±4.7 months. Clinical assessment was performed using the Harris hip score (HHS). Radiographic evaluation was performed for assessment of union of the trochanter and any mechanical failure. P<0.05 was considered statistically significant. At the latest follow-up, the mean HHS showed significant improvement from 79.9±1.8 (at three months) to 91.6±5.1 (P<0.05). In addition, no significant difference in the HHS was observed between male and female patients (P=0.29) and between fresh and failed intertrochanteric fractures (P=0.08). Union was achieved in all cases of fractured trochanter, except one. Wire breakage was observed in three patients. There were five cases of limb length discrepancy, three cases of lurch, and three cases of wire-related bursitis. There were no cases of dislocation or infection. Radiographs showed stable prosthesis in situ with no evidence of subsidence. Use of the proposed wiring technique was helpful in restoring the abductor level arm and multi-planar stability, which enabled better rehabilitation and resulted in excellent clinical and radiological outcomes with minimal risk of mechanical failure.

A Prospective, Randomized Study Evaluating Clinical and Radiographic Efficacy of Lumbar Interbody Fusion Performed Using a Truss Technology-Based Interbody Fusion Device With Homologous Bone or Bone Marrow Aspirate.

Our group used vertebral bone marrow aspirate (BMA) with an anterior truss-based interbody implant to promote fusion. This implant has biomechanical characteristics that may enhance bone on-growth and through-growth and allow for the use of BMA clot alone. The primary end point was comparison of the proportion of patients who achieved fusion with the implant packed with either crushed cancellous homologous bone chips (CCB) alone or with BMA clot alone. Patients were randomized to receive either BMA clot or CCB in the implant. Both groups also had supplemental fixation. Clinical assessments were performed preoperatively and postoperatively at 3, 6, and 12 months, including for the Oswestry Disability Index, leg and back visual analog scale, EQ5-D, reoperations, complications, and adverse events. Radiographs were obtained prior to discharge and at 3, 6, and 12 months postoperatively. A computed tomography scan was performed 3 months postoperatively. Radiographs were assessed by an independent radiologist to determine fusion status and evidence of subsidence. Between January 2015 and February 2016, 42 consecutive patients were randomized into 1 of the 2 study groups. There were significant postoperative changes within both groups in pain improvement across all outcome scales. There were no significant differences between groups in change scores from preoperative to assessments at any follow-up time point, with the exception of the change in EQ-5D and visual analog scale at 6 months; however, there was no difference at 3 or 12 months. There were no device-related adverse events in either group. All patients achieved grade II fusion at 3 months postoperatively. There was no significant difference in implant subsidence between groups or smokers versus nonsmokers. The clinical outcomes of this study suggest that reliable fusion can be obtained using an anterior truss-based implant with either CCB or BMA alone. 2.

Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: achieving lumbar interbody fusion: 196. Preoperative disc height predicts TLIF cage subsidence

BACKGROUND CONTEXT Postoperative subsidence of the transforaminal lumbar interbody fusion (TLIF) cages can result in loss of lordosis and foraminal height, and in some cases recurrence of nerve root impingement and radicular symptoms. PURPOSE The purpose of this study is to determine factors associated with TLIF cage subsidence. Specifically, we sought to determine if preoperative disc height compared to cage height could be used to predict TLIF interbody cage subsidence. STUDY DESIGN/SETTING Retrospective case-control study. PATIENT SAMPLE We identified 127 patients with complete imaging who met our inclusion criteria, with a mean clinical follow up of 27 months. OUTCOME MEASURES The primary outcome of this study was presence of cage subsidence identified with radiograph or CT. METHODS We retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. Postoperative imaging studies (radiographs and CT) were evaluated for evidence of implant subsidence. Preoperative disc height was measured for the operative and adjacent level disc heights. The delta between cage height and disc heights were measured and compared between groups. RESULTS Fifty four patients (44.3%) had evidence of interbody cage subsidence. Average cage subsidence was 5.5mm, with a range of 2.2–10.8mm. We found implant height was significantly higher in the subsidence group (12.6mm) when compared to the nonsubsidence group (11.2mm). Additionally, the delta between cage height and preoperative disc height was significantly larger in the subsidence group delta (5.5mm vs. 3.9mm). Similarly, the delta between cage height and preoperative adjacent level disc height was also significantly larger (1.2mm vs. 3.8mm). CONCLUSIONS This study demonstrates that preoperative disc height and preoperative adjacent level disc height can be used to template TLIF cage height to potentially decrease rates of subsidence. Larger cages subsided more frequently than smaller cages. Patients with evidence of subsidence had larger deltas between cage height and preoperative disc height. Similarly, a significant difference existed if preoperative adjacent level disc height was compared to cage height. This demonstrates that preoperative imaging should be used for TLIF cage height templating to avoid subsidence.

Short-term Complications, Reoperations, and Radiographic Outcomes of the Infinity Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: With the increasing use of total ankle arthroplasty (TAA), new implants with varied configurations are being developed every year. This study aims to provide the early complications, reoperations and radiographic and clinical outcomes of the Infinity TAA. To date, clinical results of this novel fixed-bearing implant have not been published. Methods: A retrospective analysis of 64 consecutive ankles that underwent a primary Infinity TAA from July 2014 to April 2016 was performed. Patients had an average follow-up of 24.5 (range, 18-39) months. Medical records were reviewed to determine the incidence of complications, reoperations and revisions. Radiographic outcomes included preoperative and postoperative tibiotalar alignment, tibial implant positioning, the presence of periprosthetic radiolucency and cysts, and evidence of subsidence or loosening. Additionally, patient-reported outcomes were analyzed with the Foot and Ankle Outcome Score (FAOS) preoperatively and 1-year postoperatively. Results: Survivorship of the implant was 95.3%. Fourteen ankles (21.8%) presented a total of 17 complications (Table 1). A total of 12 reoperations were necessary in 11 ankles (17.1%). Revision surgery was indicated for 3 ankles (4.7%) due to isolated subsidence of the tibial implant in 2 cases and due to subsidence of both the tibial and talar components in 1 case. Tibiotalar coronal deformity was significantly improved after surgery (P &lt; .0001) and maintained during latest follow-up (P = .81). Periprosthetic radiolucent lines were observed around the tibial component in 20 ankles (31%) and around the talar component in 2 ankles (3.1%). A tibial cyst was observed in 1 ankle (1.5%). Outcome scores were significantly improved for all FAOS components analyzed (P &lt; .0001). Conclusion: Most complications observed in the study were minor and successfully treated with a single reoperation procedure or nonoperatively. Failures and radiographic abnormalities were most commonly related to the tibial implant. Further studies with longer follow-up are needed to evaluate the survivorship of the tibial implant in the long-term.

Short-Term Complications, Reoperations, and Radiographic Outcomes of a New Fixed-Bearing Total Ankle Arthroplasty

With the increasing use of total ankle arthroplasty (TAA), new implants with varied configurations are being developed every year. This study aimed to assess the early complications, reoperations, and radiographic and clinical outcomes of the Infinity TAA. To date, clinical results of this novel implant have not been published. A retrospective analysis of 64 consecutive ankles that underwent a primary Infinity TAA from July 2014 to April 2016 was performed. Patients had an average follow-up of 24.5 (range, 18-39) months. Medical records were reviewed to determine the incidence of complications, reoperations, and revisions. Radiographic outcomes included preoperative and postoperative tibiotalar alignment, tibial implant positioning, the presence of periprosthetic radiolucency and cysts, and evidence of subsidence or loosening. Additionally, patient-reported outcomes were analyzed with the Foot and Ankle Outcome Score (FAOS). Survivorship of the implant was 95.3%. Fourteen ankles (21.8%) presented a total of 17 complications. A total of 12 reoperations were necessary in 11 ankles (17.1%). Revision surgery was indicated for 3 ankles (4.7%) as a result of subsidence of the implant. Tibiotalar coronal deformity was significantly improved after surgery ( P < .0001) and maintained during latest follow-up ( P = .81). Periprosthetic radiolucent lines were observed around the tibial component in 20 ankles (31%) and around the talar component in 2 ankles (3.1%). A tibial cyst was observed in 1 ankle (1.5%). Outcome scores were significantly improved for all FAOS components analyzed ( P < .0001), from 39.0 to 83.3 for pain, from 34.0 to 65.2 for symptoms, from 52.3 to 87.5 for activities of daily living, and from 15.7 to 64.2 for quality of life. Most complications observed in the study were minor and successfully treated with a single reoperation procedure or nonoperatively. Failures and radiographic abnormalities were most commonly related to the tibial implant. Further studies with longer follow-up are needed to evaluate the survivorship of the tibial implant in the long term. Level IV, retrospective case series.

Morphology and distribution of dolines on ultramafic rocks from airborne LiDAR data: the case of southern Grande Terre in New Caledonia (SW Pacific)

AbstractDolines are closed geomorphological depressions which are surface manifestations of karstic systems. Usually developed on limestones, they also typify the morphology of the New Caledonian landscape, particularly on the southern massif of the main island (known as Massif du Sud). The specificity of dolines here lies in their development on ultramafic rocks. They are evidences of subsidence, suffosion and collapse phenomena resulting from dissolution weathering of peridotites. However, extensive underground drainage systems are still not yet recognized.Semi‐automatic mapping of dolines is carried out on a 148 km2 area of the Massif du Sud from a high accuracy LiDAR digital elevation model. In this area 8601 dolines ranging from 1 m2 to 2 km2 are identified and morphologically characterized with precision. Most are small, shallow and round‐shaped, yet more complex shapes are locally observed. Size distribution analysis allows the setting of a threshold of 20 000 m2 above which surface processes rather than chemical weathering control doline evolution. Doline density analysis reveals high concentrations on flat areas where ferricrete overlies the complete weathering profile, especially in the case of elevated rainy watersheds. Dolines are aligned and elongated along a north 135° ± 5° major fracture direction, which is inherited from the obduction of the Pacific Plate upper mantle in the Late Eocene.Finally, we propose a pioneering morphometric typology of dolines that provides important clues as to pseudokarstic activity. We define collapse, bowl‐shaped and flat bottom dolines. Collapse and bowl‐shaped dolines are assumed to denote active pseudokarst. They may widen and deepen, or eventually be filled by sediments. They are distinguished from flat bottom dolines that are partially to completely filled, which suggests that they are associated with paleo‐pseudokarsts. However the groundwater flow paths associated with the genesis and evolution of dolines must be clarified, thus collapse and bowl‐shaped dolines should be hydrologically monitored. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Mid-term results of ceramic on ceramic total hip replacement in young adults

Background: With the increased use of (THA) in younger patients with more activity and more wear and ‎stress, the ceramic on ceramic bearing surfaces decrease the rates of wear and increase the prosthesis ‎longevity. ‎ Patients and Methods: 58 patients (66 hips) evaluated after THA operation using ceramic bearing surfaces. ‎There were 40 males and 18 females with mean age of 34 years (range: 26-48). The etiology was avascular ‎necrosis of femoral head in 42 hips, and posttraumatic hip arthrosis in 24 hips. Clinically, the ‎indications of operation were disabling pain, marked restriction in hip motions, and flexion adduction ‎deformity. Harris hip score was used in clinical ‎evaluation preoperatively, postoperatively and at last follow ‎‎up for all patients. For radiological evaluation we used the criteria of Lins et al for acetabular evaluation ‎and Engh et al. for femoral evaluation. ‎ Results: The mean follow-up period was 82 (range, 66–102) months. Clinically, the mean Harris Hip Score ‎improved from 50.5 (range, 24–66) to 89 (range, 45–98) [p < 0.001]. At the last follow ¬up, excellent results ‎were in 24 hips (36.5%), and good results in 30 (45.5%), fair in 8 hips (12%), and 4 hips (6%) had poor results. ‎No hip had evidence of subsidence, loosening, or osteolysis. A radiolucency of 1 mm of was seen in 2 ‎zones in 8 hips (14%), (in 5 hips it was in zones 1 & 2, and in zones 2 & 3 in 3 hips). There were no ‎progression of these lucencies up to last follow up. In the femoral stem, there were four stems with ‎radiolucent line of 3mm in 2 zones but clinically the patients had no pain and stems were stable until last ‎visit. ‎ Conclusion: ‎ Total hip replacement with ceramic on ceramic bearing surfaces are functioning well with minimal complications and low rate of loosening in a 5-8 years follow up according to this study.

Subsidence in Single Level Cervical Disc Arthroplasty

Introduction Motion preservation with cervical disc arthroplasty implants has consistently been shown, in numerous randomized controlled trials, to produce equivalent or superior clinical outcomes to anterior cervical decompression and fusion. Therefore, there has been a call, within the spinal surgery community, to compare outcomes between arthroplasty implants. Although it is important to evaluate positive outcomes, it is also of vital importance to analyze complications and assess the potential influence of different implant designs on complications. We have experience in a large series of using several different arthroplasty implants. We have reviewed our series and have identified implants that have subsided. We provide a commentary on these cases. Material and Methods A retrospective review of all single-level anterior cervical decompression and disc arthroplasty cases, performed at the authors' institution, between 2006 and 2012 was conducted. Postoperative X-rays were assessed for any degree of subsidence compared with immediate postoperative X-rays. Cases with evidence of subsidence were studied for potential implicated factors. Results A total of 157 cases were reviewed consisting 64 PRESTIGE LP Cervical Disc System (Medtronic, Minnesota, United States), 51 NUNEC Cervical Arthroplasty System (RTI Surgical, Inc., United States), 35 Discocerv (Scient'x-Alphatec Spine, Arras, France), and 7 other implants in small numbers. Overall, 11 (7%) cases showed evidence of implant subsidence—two (3%) PRESTIGE LP, five (10%) NUNEC, and four (11%) Discocerv. In the cases that subsided, there were three males and eight females. There was a following variety of location of subsidence: anterior, posterior and complete surface of the implant, superior, and inferior. Seven of the cases did not fully cover the disc space in the anteroposterior plane. Three cases appeared to have been impacted into osteophytes posteriorly but subsidence was not necessarily in this location. The majority of cases appeared to have abnormal motion/spondylotic changes in adjacent levels, raising the possibility of abnormal forces being placed through the replaced level. Conclusion Cervical disc arthroplasty implant subsidence may be influenced by implant design, patient factors, and surgical technique. In this series, because of the small number of cases that showed subsidence, we cannot draw any firm conclusions. This report nevertheless should serve as an important stimulus for discussion and development regarding modifiable factors implicated in complications such as device subsidence.

Ceramic-on-ceramic total hip arthroplasty in patients younger than 55 years.

To review the outcomes of 65 patients younger than 55 years who underwent uncemented total hip arthroplasty (THA) using third-generation ceramic-on-ceramic prostheses. Medical records of 30 men and 35 women (80 hips) aged 18 to 55 (mean, 39) years who underwent uncemented THA using third-generation ceramic-onceramic prostheses by a single surgeon were reviewed. 61 THAs used the Reflection cup with the Synergy stem (n=49), Spectron stem (n=7), or Anthology stem (n=5), and 19 THAs used the Trident cup with the Secur-Fit stem. Outcomes were assessed based on the UCLA Activity Score and Harris Hip Score, as well as radiolucency around the implants, malposition, and subsidence on radiographs. Patients were asked about their satisfaction with current activity level (yes/no), activity limitation (no limitation, musculoskeletal limitation, psychological impediments and lack of motivation, and pain or disability of the operative hip), and change in occupational activity level (same or similar, more active, and less active or disability). The mean follow-up period was 54 (range, 24-110) months. Six patients were excluded from the analysis owing to prosthetic failure secondary to ceramic liner fracture after falling (n=2), acetabular component loosening (n=1), intolerable squeak (n=1), periprosthetic fracture (n=1), and instability (n=1). The mean UCLA Activity Score improved from 4.0 (range, 1-10) to 7.7 (range, 2-10) [p<0.001], and the mean Harris Hip Score improved from 52.8 (range, 25-69) to 91.0 (range, 38-100) [p<0.001]. No hip had evidence of subsidence, loosening, or osteolysis. 52 (80%) patients were satisfied with their activity level; 28 (43%) patients reported no activity limitation; and 57 (88%) patients kept the same or similar occupation. Ceramic-on-ceramic THA achieved acceptable clinical and radiographic outcomes.

Detection of geophysical features in InSAR point cloud data sets using spatiotemporal models

In this article, we introduce an approach for detecting evolving geophysical features within interferometric synthetic aperture radar (InSAR)-derived point cloud data sets. This approach is based on the availability of models describing both spatial and temporal behaviours of the geophysical features of interest. The model parameters are used to generate a multidimensional space that is then scanned with a user-defined resolution. For each point in the parameter space, a spatiotemporal template is reconstructed from the original model. This template is then used to scan the point cloud data set for regions matching the spatiotemporal behaviour.We also introduce a proportional measure where the residual for each point in the data set is compared to both the data and the template to provide a scale invariant measure of the behavioural matching. The matching is evaluated for every point in the parameter over a region of influence determined by the parameters. The resulting multidimensional space is then collapsed onto geographical coordinates to produce an overlay map identifying regions whose spatiotemporal behaviour matches the feature of interest.We tailored our approach to the detection of subsidence behaviour, indicative of the development of sinkholes, modelled as Gaussian with amplitude linearly increasing with time. We verified the validity of our model using both synthetic and actual InSAR data sets. The latter was obtained by processing imagery of a region near Wink, Texas, containing ground truth sinkhole data.We applied this framework to a 40 km × 40 km area of interest located in western Virginia and performed ground validation on a subset of the identified regions. The results show good agreement between the locations detected by our algorithm and the evidence of subsidence observed during the ground validation campaign.

Study of Disaster Mitigation for Car Nicobar Isl and Using Remote Sensing and GIS

December 26th 2004 earthquake wi th 9.3 Mw caused one of the deadl ies t Tsunami in the human history . Subsidence of land mass t o 1.5 m along the e astern part of ent ire Andaman and Nicobar islands and up l i ft of 1.5 m in the western margins of the island system were observed. Most of the islands are const i tuted wi th folded mountain bel ts, except Car Nicobar. The epicenter of December 26, 2004 Sumatra earthquake was 163 km away from Great Nicobar, the southernmost island and hence i t was strongly fe l t in the ent ire Andaman & Nicobar group of i slands including Car Nicobar. Evidence of subsidence was also observed at the Car Nicobar the northernmost island of the Nicobar group (N9.2 o lat . , E92.4 o long). Car Nicobar is being almost f lat terrain to the east and an e levated terrain wi th maximum elevat ion of about 70 m to the west and hence the destruct ive Tsunami waves engul fed in t he eastern part of the island. This island was worst af fected in terms of damage and loss of li fe . The objective of this study is to mi t igate the impact of disasters in the form of Tsunami and earthquake and cyclone for the Car Nicobar Island. Remote sensing and Geographic Information System (GIS) are important tools to prepare thematic maps by incorporat ing the e levat ion data, to del ineate the extent of t sunami inundat ion and the areas to locate potent ial hazard zones of Car Nicobar Island. Preparat ion of i nundat ion maps of coastal areas helps to ident i fy regions from tsunami at tack. Tsunami risk analysis helps to manage the evacuation planning and to diminish the loss of the li fe by tsunami . Preparat ion of land-use pat tern is re levant for rehabi l i tation man agement and to reduce potent ial damages. From the past source, i t i s very c lear that the Car Nicobar was most af fected by se ismic induced tsunami. The study is carried out to sort out the risks of potent ial inundat ion area due to the tsunami along heavily populated coast l ine and provides demarcat ions of sui table si tes for rehabi l i tat ion and tools to generate the evacuation plane to mi t igate disaster happening.

Salvage of Failed Trochanteric Fracture Fixation Using the Revitan Curved Cementless Modular Hip Arthroplasty

Failed internal fixation of an intertrochanteric or subtrochanteric fracture often leads to persistent pain and diminished function. This study evaluated 16 patients treated with Revitan curved cementless modular stem (Zimmer GmbH, Winterthur, Switzerland). At a mean follow-up period of 60 months, all patients demonstrated clinically significant pain relief and return to ambulation after salvage total hip arthroplasty. Mean Harris Hip Score improved from 17.8 to 87.7 points postoperatively. Radiographic follow-up demonstrated stable stem and bony ingrowth in 16 patients without evidence of subsidence. Eight patients had slight awareness of lateral trochanteric pain with no compromise of activities, and 1 patient had nonunion of the greater trochanter. Revitan curved cementless modular stem represents a useful treatment option in salvage total hip arthroplasty of failed pertrochanteric fixation.

Results of revision total hip arthroplasty with Anatomic BR stem: 10-year minimum follow-up

Twenty cementless total hip revision arthroplasties using Anatomic BR stems were performed in 20 patients. Fourteen patients, with a mean age of 62.6 years (range 41–74 years) at time of revision surgery, were followed retrospectively for a minimum of 10 years (range 11–15 years). Clinical function and radiographic evidence of implant stability were evaluated. Preoperative femoral deficiencies were evaluated radiographically and classified according to Paprosky type as follows: four Type-II, four Type-IIIA, four Type-IIIB, and two Type-IV femurs. Mean preoperative Harris hip score was 46.3 points (range 29–58 points) and improved to 68.8 points (range 45–90 points) at the most recent follow-up examination. Of the 14 patients followed, six had radiographic evidence of subsidence (axial shift of more than 2 mm after revision with long-stem components). Component fixation showed bone ingrowth in three (21%) patients, inconclusive evidence of ingrowth in six (43%) patients, suboptimal but stable fixation in three (21%) patients, and unstable fixation in two (14%) patients. Based on these we results, we conclude that even with circumferential proximal porous coating and improved proximal geometry, nonmodular femoral implant stability remains unpredictable following total hip arthroplasty revision.

Submerged notches and doline sediments as evidence for Holocene subsidence

The possibility of Holocene subsidence along the northern coast of the Corinth Gulf is often mentioned in the literature; however, systematic detailed evidence that submergence (e.g. of archaeological remains) does not simply depend from eustatic sea-level rise is most often missing. In this paper, a new detailed study of submerged tidal-notch profiles along the limestone coast has shown that periods of sea-level stability are intercalated with periods of rapid subsidence or gradual relative sea-level rise. It appears that most of the sites considered, seem to have been affected by a relatively recent co-seismic subsidence of about half a meter, whereas during the longer period, by stages of relative sea-level stability and/or gradual relative sea-level rise. This evidence of subsidence is confirmed by radiocarbon dating in doline sediments, suggesting that during certain periods, a relative sea-level rise was much faster than the raising suggested by glacio-eustatic or hydro-isostatic estimations. Juxtaposing a list of known earthquakes occurred in the area shows that several earthquakes (e.g. the 1981 one for the easternmost sites considered) are potential candidates for the recent co-seismic displacements and thus supporting the geomorphological interpretations.

The Use of a Cementless Modular Stem in the Treatment of Subtrochanteric Femoral Fractures in Conjunction with Ipsilateral Coxarthrosis

Subtrochanteric fractures of the femur below an arthritic hip are uncommon and challenging to orthopedic surgeons. Most of these fractures occur in elderly patients with advanced osteoporosis. The treatment choices consist of treatment of the fracture and the above hip joint versus treatment of the fracture alone. This study evaluates the clinical and radiological outcomes of arthroplasties performed to treat both conditions in a single surgery with the use of a cementless modular revision stem. Twelve subtrochanteric femoral fractures of 12 patients (9 women, 3 men) with a mean age of 76.4 years (range, 62-88 years) were treated with cementless modular revision stems. Total hip arthroplasty was performed with cementless femoral and acetabular component fixation. All hips received the same femoral and acetabular implants. All patients had comorbidities and the average American Society of Anesthesiologists score was 2.3 (range, 1-3). Ten of the 12 hips (83%) required an assistance device for ambulation before the trauma. There were 2 Dorr Type A (17%), 3 Dorr type B (25%), and 7 Dorr type C (58%) femora. The mean postoperative Harris Hip Score was 83 (range, 72-92) with a mean follow-up of 4.3 years (range, 2-7 years). At final follow-up, 9 hips (75%) were ambulatory without support (P=.016). Ten hips (83%) were able to both ambulate and walk up and down stairs. Two hips (17%) were able to ambulate but could not climb and descend stairs. Union was achieved in all femora at an average of 22.3 weeks (range, 16-32 weeks). Radiographic findings demonstrated stable ingrowth of the femoral prosthesis with no evidence of subsidence in 11 hips (92%). The average Engh score for all femora was 20.2 (range, 10-26). There was no relationship between the bone morphology (Dorr type) of the femoral medullary canal and the bone ingrowth scores of Engh (P=.639).

Clinical performance of an elastomeric lumbar disc replacement: Minimum 12 months follow-up

Background Elastomeric disc replacements have been developed to restore normal shock absorption and physiologic centers of rotation to the degenerated disc. The Physio-L Artificial Lumbar Disc is an elastomeric disc which uses a compliant polycarbonate-polyurethane core with enhanced endurance properties. The objective of this study was to evaluate the safety and efficacy of the Physio-L through a 12-month follow-up period in a prospective, nonrandomized clinical trial. Methods Twelve patients who met the inclusion/exclusion criteria were enrolled in the study. Eight patients received a single implant (L5-S1) and 4 received a 2-level implantation (L4-5 and L5-S1). Patients were assessed preoperatively and postoperatively at 6 weeks and 3, 6, and 12 months. Primary outcomes included the VAS, ODI, a radiographic analysis of implant condition, incidence of major complications, and reoperations. Secondary outcomes included SF-36, ROM at index and adjacent levels and disc height. Results All patients completed the 12-month follow-up evaluations. Through 12 months, the Physio-L devices have remained intact with no evidence of subsidence, migration, or expulsion. VAS low-back pain and ODI scores improved significantly at all follow-up periods compared to preoperative scores. The range of motion of 13.3° ± 5.5° at the index level was considered normal. Overall, patients were satisfied with an average score of 83.5 ± 26.8 mm. When comparing the device to other artificial discs, the current device showed a clinically relevant improvement in both ODI and VAS scores at all follow-up time points. Statistically significant improvements in both scores were observed at 12 months ( P < .05). Conclusion The Physio-L is safe and efficacious, as demonstrated by improved pain relief and functional recovery without any implant failures, significant device related complications, or adverse incidents. The clinical results for VAS and ODI were superior to other marketed artificial lumbar discs such as the Charité and ProDisc-L at the same follow-up timeframes.

Characterization of karst hazards from the perspective of the doline triangle using GPR — Examples from Central Ebro Basin (Spain)

Ground Penetrating Radar (GPR) is a widespread technique to locate and characterise karst hazards (cavities and paleocollapses). In this paper, we show that the internal structure of sediments obtained from GPR surveys can also be used as an indicator of active karst processes. A classification of karst hazard problems by means of GPR in the GPR-doline triangle is proposed, with three end-members: cavities, evidences of subsidence and paleocollapses. These end members show particular signatures in the GPR-profiles. The field examples shown in this paper indicate that GPR survey is a geophysical technique that offers a very high resolution and provides structural and sedimentological information of the subsoil. The use of grid maps, elaborated from GPR data, is an efficient way to determine anomalous sectors (lateral changes of electromagnetic properties, different reflectivity and qualitative penetration depth variations or velocity wave propagation changes). Their relationships with the structural features obtained from GPR-profiles (on-lap geometries, zones with depressed reflectors, folded reflectors or laterally abrupt structural limits) can be used as indicators of karstic processes.

Observations of Gap Flow in the Wipp Valley on 20 October 1999: Evidence of Subsidence

Abstract Using extensive observations collected from various platforms around the Brenner Pass in the Austrian Alps during the Mesoscale Alpine Programme, a detailed description of the kinematic and thermodynamic structure of the shallow-foehn event that occurred on 20 October 1999 in the Wipp Valley is constructed. Downstream of the gap the flow develops a well-mixed surface layer capped by a relatively strong temperature inversion of 5–6 K. Such inversions are often assumed to be kinematically similar to the free surface at the top of a liquid; however, the data suggest the presence of strong subsidence through the mean position of the inversion layer capping the flow. Such subsidence is supported by in situ aircraft observations and Doppler lidar measurements but is not consistent with the observed turbulent heat fluxes, which are too small to account for the diabatic heating required by the isentrope-relative downward velocities. The 1-Hz time resolution of the P3 data may, however, be too coarse to correctly capture the full turbulent heat flux.