bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomechanics of a New Short-Stemmed Uncemented Hip Prosthesis: An In-Vitro Study in human Bone
Authors: Westphal F.M. , Bishop N. , Püschel K. , Morlock M.M.
Published: January 2018

The migration pattern, cyclic motion, system stiffness and failure load of a new short-stemmed hip prosthesis were compared to a clinically successful shaft prosthesis during the initial loading phase. The influence of implant-sizing on mechanical stability was also investigated for the new stem, in particular with relation to the bone quality. Prostheses were implanted in paired human femora and loaded cyclically up to 3515 cycles. Relative displacements between prosthesis and bone were measured using a 3D-camera and reflective marker system. Migration of the new stem was predominantly into varus and was higher than for the shaft prosthesis. The test set-up was proposed to simulate a worst-case loading scenario since muscle forces, which tend to reduce bone deformation, were not simulated. It could therefore be expected that clinical migration of the implants would be less pronounced than that observed in this study. Cyclic motion for the new stem was similar to that for the clinically successful shaft prosthesis, suggesting that bone ingrowth could be expected for the new stem. No significant difference in fracture load was observed between the implants. The system stiffness with the new stem was lower than for the shaft prosthesis, indicating more physiological load transfer. Smaller implant sizing with ‘cancellous’ fixation seems favourable, as it led to similar migration and smaller cyclic motion values than with ‘cortical’ fixation. A trend for higher cyclic motion and migration was observed in femora with poor bone quality. Hence, sufficiently good bone stock is necessary, when implanting the new short-stemmed prosthesis.
Tribology Considerations for Hip Joint Articulations in Relation to the “New Orthopaedic Patient”
Authors: Rieker C.B.
Published: January 2018

The purpose of this review is to examine alternative bearings used in total hip arthroplasty (THA) and discuss the specific tribologic needs of the “New Orthopaedic Patient”. As orthopaedic patients today are younger and more active, there is a clear need for hip joint implants and articulations minimising the amount of wear and guarantying better stability.

Recent modern developments in tribology with highly cross-linked polyethylenes and hard-on-hard bearings allow the safe and effective use of larger diameter articulations in THA.
Cost-Benefit Analysis of Mis Tha: Model-Based Analysis of the Consequences for Switzerland
Authors: Straumann D. , Valderrabano V. , Eckstein M. , Dick W. , Dora C.
Published: January 2018

The objective of this study was to show model-based economic consequences of minimal invasive surgery total hip arthroplasty (MIS THA). The model is based on hospital and rehabilitation costs and lowering of loss of productivity. This study used conventional THA data from Switzerland and cost-effectiveness MIS THA analysis from the United States. According to our model, a total of € 42.1 – 70.1 million can be saved annually in Switzerland when using MIS THA instead of conventional THA. Annual savings of € 7,8 – 12,9 million result from the significantly shorter hospital stay. The savings potential for rehabilitation costs is € 10,5 – 17,5 million annually. In addition, the productivity loss for the economy is lowered by € 23.8 – 39.7 million annually. According to this economic study we recommend the introduction of MIS techniques in THA. MIS THA surgical techniques may allow the reduction of healthcare costs. Despite the promising economic advantages of MIS THA, clinical studies are necessary to prove long-term benefits.
Long-Term Results with the Wagner Metal-On-Metal Hip Resurfacing Prosthesis
Authors: Böhm R. , Schraml A. , Schuh A.
Published: January 2018

The purpose of this study was to report the long-term results of the metal-on-metal Wagner resurfacing prosthesis. Between January 1991 and August 2004, 54 Wagner resurfacing prostheses were implanted in 52 patients. There were 45 female patients (1 bilateral case) and 7 male patients (1 bilateral case). All the operative procedures were performed using the anterior approach. Of those cases available, the average time to follow-up was nine years. The average Merle d'Aubigné score improved from 8.3 preoperatively to 17.3 postoperatively (p-value < 0.001). Seventeen prostheses required revision. Radiographic evidence of femoral neck narrowing was seen in three prostheses that remained in situ. Combined with a stricter diagnosis and an exact operating technique, the Wagner metal-on-metal surface replacement of the hip joint may offer an alternative surface replacement option.
The Development of the Durom™ Metal-On-Metal Hip Resurfacing
Authors: Grigoris P. , Roberts P. , Panousis K.
Published: January 2018

The poor results of conventional total hip replacement in young and active patients have led to a renewed interest in alternative interventions and bearing material combinations. Contemporary metal-on-metal resurfacing of the hip has emerged as an attractive option. This procedure utilises a low wear producing bearing which minimises the risk of periprosthetic osteolysis, preserves femoral bone stock should subsequent procedures become necessary, and, due to the increased stability and range of motion, allows the rapid resumption of an active lifestyle. We describe the development of the Durom™ metal-on-metal hip resurfacing and report the preliminary results of the first 100 consecutive cases.
Factors Affecting the Cement Penetration of a Hip Resurfacing Implant: An in Vitro Study
Authors: Howald R. , Kesteris U. , Klabunde R. , Krevolin J.
Published: January 2018

An understanding of how the cementing technique influences cement penetration is important for surgeons to plan and conduct hip resurfacing procedures. Therefore the aim of this study is to determine the influence of the following parameters on cement penetration: use of pulse lavage, type of cement, and the standing period of the cement.

Nine fresh frozen paired whole cadaver femora were used to investigate cement penetration. The femora were divided into three paired groups: (A) compared the use of pulse lavage to no pulse lavage, (B) compared two low viscosity bone cements SULCEM-3 (Zimmer GmbH, Switzerland) and Surgical Simplex (Stryker Orthopaedics, USA), and (C) compared bone cement viscosities using standing times of 1.5 min. and 3 min. The Durom Hip Resurfacing implant (Zimmer GmbH, Switzerland) was used in all groups.

A single slice was taken out of the center of each head. Cement penetration ratio (penetration area divided by the bone area enclosed by implant) and mean cement penetration depth were measured. Cement penetration is increased using pulse lavage, and has the tendency to increase with increasing the cement standing time from 1.5 to 3 min. No difference in cement penetration was found when different cement brands of comparable viscosity were used.
A District General Hospital'S Experience of Hip Resurfacing
Authors: McANDREW A.R. , Khaleel A. , Bloomfield M.D. , Aweid A.
Published: January 2018

In our unit 180 consecutive hip resurfacing procedures have been performed. All patients had a posterior approach to the hip joint, followed by standard resurfacing using metal-on-metal components. The patients were evaluated radiographically and clinically preoperatively and postoperatively.

The mean age of patients was 56 years (range 25–75). There was a statistically significant improvement between the preoperative Harris Hip Score and those at the latest follow-up. There were four fractures of the femoral neck; one was intra-operative and was converted to total joint arthroplasty. Three further fractures occurred: two were revised and one was treated non-operatively There were no cases of dislocation or deep infection.

The short- and medium-term results that have been achieved in this district general hospital are comparable to those that have been achieved in the originator's institution.
A Review of Ceramic Bearing Materials in Total Joint Arthroplasty
Authors: Bal B.S. , Garino J. , Ries M. , Rahaman M.N.
Published: January 2018

Bearings made of ceramics have ultra-low wear properties that make them suitable for total hip arthroplasty (THA) and total knee arthroplasty (TKA). When compared to cobalt chrome (CoCr)-on-polyethylene (PE) articulations, ceramics offer drastic reductions in bearing wear rates. Lower wear rates result in fewer wear particles produced by the articulating surfaces. In theory, this should reduce the risk of periprosthetic osteolysis and premature implant loosening, thereby contributing to the longevity of total joints. In addition to ceramics, other alternative bearing couples, such as highly cross-linked PE (XLPE) and metal-on-metal also offer less wear than CoCr-on-PE articulations in total joint arthroplasty.

Alumina and zirconia ceramics are familiar to orthopaedic surgeons since both materials have been used in total joints for several decades. While not new in Europe, alumina-on-alumina ceramic total hips have only recently become available for widespread use in the United States from various orthopaedic implant manufacturers. As the search for the ideal total joint bearing material continues, composite materials of existing ceramics, metal-on-ceramic articulations, and new ceramic technologies will offer more choices to the arthroplasty surgeon. The objective of this paper is to present an overview of material properties, clinical applications, evolution, and limitations of ceramic materials that are of interest to the arthroplasty surgeon.
Z-Lengthening of the Iliotibial Band to Treat Recalcitrant Cases of Trochanteric Bursitis
Authors: Chirputkar K. , Weir P. , Gray A.
Published: January 2018

Greater trochanteric bursitis is a relatively common presentation at hip clinics.

It presents with pain around the greater trochanter. Diagnosis is usually made on clinical grounds when other hip and spinal pathologies are ruled out and there is tenderness present over the trochanteric region. Rheumatoid arthritis (1), athletic injury (2), total hip arthroplasty (3) and idiopathic disease (4) are some of the known causes of trochanteric bursitis. Treatment is mainly non-operative and expectant; however various operative interventions have been described in the literature.

We present a series of 16 patients who had recalcitrant trochanteric bursitis following failed non-operative treatment and were treated with bursectomy and Z-lengthening of the iliotibial band. All 14 patients who answered the questionnaire were happy with the outcome of operation and 13/14 patients would undergo a similar procedure again. To the best of our knowledge, this is the only series in the literature describing this particular procedure for treatment of trochanteric bursitis.
Effect of Femoral Stem Centralizer Design on Cement Mantle Porosity
Authors: Anderson A.J. , Smyth E. , Morgan A. , Hamer A.J.
Published: January 2018

We studied whether prosthetic femoral stem centralizers have a detrimental effect on the macroporosity of the cement mantle. With pressure and time monitoring identically cast, moulded prosthetic femora had Charnley C-stems implanted. The stems were removed and the cement mantle was sectioned and photographed to record the size and location of voids (macropores). Cement voids were found in 85% of femora when a centralizer was used compared to 20% of the control group (p=0.002). A modular centralizer produced cement voids of a larger volume and more frequent occurrence (p=0.002). The macroporosity of the cement mantle was independent of the rate of implantation (p=0.39). Modern distal stem centralizers therefore increase the incidence of void formation in the cement mantle; although they help guard against malposition of the implant, they may have implications for early loosening.
The Role of Acetabulum Geometry and Femoral Head-Neck Ratio in the Development of Osteoarthritis in Young Men
Authors: Halle B. , Halle D.M. , Torfing T. , Overgaard S.
Published: January 2018

We studied the role of acetabulum geometry and head neck ratio in the development of osteoarthritis of the hip in young men. Contrary to previous studies we evaluated the significance of the anterior, posterior and total coverage of the femoral head, the influence of the femoral neck and the consequence of acetabular retroversion on standardized x-rays. Men aged 26–55 years who earlier had a total hip arthroplasty were included in the case group. This group was compared to a control-group of men treated as trauma patients. The study indicates that acetabular dysplasia and retroversion and a relative decreased head neck ratio are associated with osteoarthritis of the hip in young men.
Radiologic Evaluation of the Cement Mantle in the Femoral Shaft. A Comparative Study Using a Fast-Set or a Standard-Set Cement
Authors: Gallart X. , Martínez F. , García S. , Riba J. , Combalía A. , Ballesteros J. , Elefante F. , Calonego G.
Published: January 2018

Introduction

At present a wide spectrum of cement types are available for cemented total hip arthroplasty (CTHA). All types have the same objective, i.e. to prolong the life of the implant for as long as possible. The purpose of this study was to compare the radiologic cement mantle of CTHA using cement with fast or standard setting characteristics.

Method

A prospective comparative study of patients who underwent CTHA was performed: the first group received fast setting cement (Cemex System Fast), the second group received standard setting cement (Cemex System). A radiologic evaluation of the cement mantle was done using Barrack's classification. In order to give the study clinical relevance we assembled Barrack's classification in two groups: 1) Low risk group (Types A and B); 2) High risk group (Types C and D). According to ISO 5833:2002, the international standard was used to perform physico-chemical (polymerization temperature, setting time) and mechanical testing (compression strength, bending strength and bending modulus).

Results

The fast setting cement showed a shorter setting time and a higher polymerization temperature. The mechanical performances of both cements met the ISO limits. At a mean follow-up of 23 months (11–37 months) no statistically significant radiological difference was found in the radiologic cement mantle between the two groups either in the post-operative X-ray evaluation (p=0.32) or in the last follow-up (p=0.72). Statistical evaluation was done comparing the two subgroups, i.e. low risk and high risk.

Conclusions

The use of fast or standard setting cement does not produce any difference in the quality of the radiologic cement mantle in the short-term. Both cements comply with ISO 5833 requirements.
Recurrent Total Hip Arthroplasty Dislocation in Combination with Massive Osteolysis: An Outline of Management Using a Proximal Femoral Replacement
Authors: Kundra R.K. , Bhattacharya S. , Lawrence T.
Published: January 2018

Recurrent dislocation of a total hip arthroplasty is a most distressing complication for both patient and surgeon. The situation is worsened when massive osteolysis occurs in combination with recurrent dislocation. Management options become more limited in this situation. We present such a case along with a discussion of the management options utilised.
Early Diagnosis and Treatment of DDH: A Sonographic Approach
Authors: De Pellegrin M. , Moharamzadeh D. , Fraschini G.
Published: January 2018

This study reviews the data regarding clinical and ultrasound (US) examinations, collected during an 11-year period, in a DDH dedicated outpatient clinic. The material was analysed in order to verify the importance of US hip examination and Ortolani's test for early DDH diagnosis, to select dysplastic, unstable hips, to identify the role of the labrum in DDH, and to analyse the treatment strategy Of the 21709 newborns (43418 hips) examined with US and Ortolani's manoeuvre for DDH diagnosis, 431 patients (356 F; 75 M; average age 42 ± 33 days) had 574 unstable, dysplastic hips (1.32%). The hips identified according to Grafs classification were: 298 type D, 252 type IIIa, 4 type IIIb, 20 type IV. In 73.09% of the patients, no risk factors were identified; 18.56% had positive family history for DDH, 5.57% had breech presentation, 2.78% had both risk factors. Only 10.63% had a positive Ortolani's test. The diagnosis was made in 21.5% of cases by the 2nd week of life, in 52.9% between the 2nd-8th week, and in 25.5% after the 8th week. Unstable dislocated hips were treated, after reduction with or without sedation, by applying a cast; dysplastic hips were treated using a Gekeler splint. No open reductions or reconstruction surgery were needed. The labrum was always positioned on top of the femoral head, never inverted, and it was not an obstacle to closed reduction. Neither the Ortolani's sign, nor the risk factors are sure signs for the early diagnosis of DDH and its instability. Only US examination permits an early diagnosis of dysplasia and instability of the hip.
Morphological Variations of Residual Hip Dysplasia in the Adult
Authors: Ganz R. , Leunig M.
Published: January 2018

Common understanding of residual hip dysplasia of the adult characterizes it as a uniform, anterolateral insufficiency of femoral head coverage; the proximal femur may or may not have increased valgus and antetorsion. This view is reflected by the parameters used for quantification but also by the classic surgical approaches to compensate or correct the deformity. More than two decades of dedication to hip dysplasia and its surgical treatment, but also the application of modern diagnostic tools such as magnetic resonance arthrography have allowed us to portray hip dysplasia more polymorphically showing a number of additional aspects with pathophysiologic, therapeutic and prognostic valence.

The rim in acetabular dysplasia shows a variety of pathomorphologies ranging from hypertrophy and tearing of the labrum including fatigue fracture of the rim to degeneration with ganglion formation within the labrum, the capsule or the acetabular bone. Such rim pathology may explain sudden onset of pain but also influences the prognosis of joint preserving surgery. It is a rather new understanding that the acetabular morphology in hip dysplasia is not uniform. Pure lateral and pure anterior deficiency of coverage are small but interesting subgroups. Together with the frequent retroversion of the acetabulum these morphological and spatial aspects require special attention for a precise individual correction of the deformity. Finally, minor morphological abnormalities of the antero-lateral head-neck junction have been found to favor impingement after correction of the acetabulum. Knowledge of this problem has prompted a routine check of internal rotation in flexion during surgery and eventual arthrotomy and osteochondroplasty of the impinging site of the head and neck junction.
Surgical Treatment of Hip Dislocation in Early Infancy
Authors: Lotito F.M. , Sadile F. , Cigala F.
Published: January 2018

The necessity to operate on hip dislocation has decreased because the natural history of this congenital disease has been completely changed by using clinical and ultrasonographic screening. At present in our country surgical reduction is indicated in the rare cases of true congenital severe hip dislocation or in the few cases missed during screening. Our long experience in the treatment of such pathology since the start of the 1960s is summarized in this paper in which we describe our indications in surgical treatment of dislocated and subluxated hips affected by DDH. We point out our approach to open the dislocated hip laterally explaining the advantage of this particular and not common approach.

We also describe the radiological assessment necessary to evaluate residual dysplasia in order to plan the necessary pelvic or femoral osteotomy to correct these residual joint alterations.
Wagner's Spherical Periacetabular Osteotomy: Long Term Results
Authors: Zagra L. , Corbella M. , Giacometti Ceroni R.
Published: January 2018

Residual acetabular dysplasia leads to hip arthritis as a consequence of insufficient femoral head coverage which causes abnormal pressure on the joint cartilage.

Spherical periacetabular osteotomy, described by H. Wagner, improves the acetabular coverage of the head. This surgical technique has been performed by the senior author, in Galeazzi Orthopaedic Institute of Milan, Italy since 1979. The purpose of this study is to evaluate the clinical and radiographic results of 14 patients affected by acetabular dysplasia and operated before 1985 by the same surgeon with this technique. The analysis of long term results (follow-up longer than 20 years) has shown that it is possible to achieve good clinical outcomes and to delay the need for total hip arthroplasty if a precise surgical technique is employed and if the correct indications are followed. Obese patients or hips with X-ray signs of osteoarthritis show the worst results in our experience. Our attitude is nowadays: full indication of spherical periacetabular osteotomy in dysplasia of the adolescent, indication in young adult patients only when some symptom is present, very rare indication in arthritis and only in very mild cases in young patients.
Hip Spine Relationships: Application to Total Hip Arthroplasty
Authors: Lazennec J.Y. , Riwan A. , Gravez F. , Rousseau M.A. , Mora N. , Gorin M. , Lasne A. , Catonne Y. , Saillant G.
Published: January 2018

Lumbosacral orientation in the sagittal plane is of utmost importance, as it plays a critical role in the function of the spine and the hip joints. Equilibrium of the trunk influences the tridimensional orientation of the acetabulum and the functional range of motion of the hips. Each patient is characterized by a “morphological” parameter named incidence angle; its sagittal balance is the consequence of a postural adaptation for other functional parameters (pelvic tilt, sacral slope, lumbar lordosis, acetabular sagittal tilt, functional anteversion). Understanding variations of the sacral slope on lateral pelvic X-rays is essential for planning total hip arthroplasty and identifying patients at risk of impingement, as lumbosacral posture influences functional anteversion of the acetabulum. Posterior pelvic version as in sitting position (sacral slope decrease) is linked to the increase of the functional acetabular anteversion. Anterior pelvic version as in standing position (sacral slope increase) is linked to the decrease of the functional acetabular anteversion.
Evolution of Surgical Techniques for the Treatment of Angular and Torsional Deviation in DDH: 20 Years Experience
Authors: Grappiolo G. , Spotorno L. , Burastero G.
Published: January 2018

The anatomical abnormalities associated with developmental dysplasia of the hip (DDH) increase the complexity of hip arthroplasty In addition, previous femoral osteotomy can deform the proximal femur. Noncemented cups and stems are specifically designed for dysplasia to recover the true acetabular region in Crowe grade IV and sometimes Crowe grade III; additional surgical procedures are required. The purpose of the study was to analyse the surgical procedure and then the reconstructive options in DDH.

From 1984 until now, total arthroplasty has been performed, on dysplastic hips, in 2,101 patients for 2,308 hips (207 patients bilateral 9% rate). All the procedures were perfomed by the senior authors (LS, GG) at the same hospital specialised in elective hip surgery. More than 80% of patients came from Northern Italy. The average age was 51 (range 32–83), 565 cases had involved a previous femoral osteotomy. Out of these 2,308 cases, 128 cases needed treatment for corrections of femoral side deformity; 64 cases were subjected to a greater trochanter osteotomy. In 12 cases, proximal femur shortening was involved. In 9 cases, rotational abnormality and shortening were controlled with a distal femur osteotomy. Fifty-five cases were treated by a shortening subtrochanteric osteotomy that allows corrections of any deformity. Only noncemented stems were used. Long-term results in these patients are consistently inferior (70% survival rate at 15 years) compared to those in the non-DDH population (97.7% survival at 15 years). On the femoral side, early failures are the reflection of a learning curve and are due to insufficient fixation of the osteotomy.

The more promising outcomes are those involving a shortening subtrochanteric osteotomy.
“Conus” Uncemented Stem in Developmental Hip Dysplasia
Authors: Cherubino P. , Zatti G. , D'angelo F. , Murena L. , Monzeglio D.
Published: January 2018

The purpose of this study was to evaluate 115 “Conus” uncemented stems at an average follow-up of 6 years (2–9 years). Seventeen patients were lost at follow-up for a final number of 98 stems in 75 patients. The clinical outcome of 71 hips (72%) was graded excellent, 25 (25%) were good, one (2%) fair and one (2%) poor. The average Harris Hip Score increased from 49.35 before operation to 96.30 at the time of the last follow-up.

None of the stems implanted required a revision for aseptic or septic loosening. Cortical hypertrophy or radiolucencies were never seen in any of the stems evaluated. Heterotopic ossification was seen in one hip (1%). Modification of the calcar was observed in 29 hips (30%) and they consisted in a slight rounding off of the proximal medial edge of the cut femoral neck.

These results encourage the use of this versatile stem which showed a good primary and secondary stability, with a good load distribution along the femur.
Modular Stems in DDH
Authors: Benazzo F. , Cuzzocrea F. , Stroppa S. , Ravasi F. , Dalla Pria P.
Published: January 2018

The Modulus (Lima-Lto) system has been created on the association of a conical stem and a modular neck in order to address the so called “difficult hip”. Modularity can maximize the options for a correct reconstruction in a total hip replacement of the coxofemoral anatomy as well as biomechanics.

Modulus should be used in CDH, primary hip arthritis, the sequelae of osteotomies and in each case in which we face a congenital or acquired hip deformity.

The Modulus stem has been commonly utilised in association with the Delta cup (Lima-Lto) with the chance to use big diameter heads (32–36 mm) and ceramic on ceramic coupling.

Modulus has been used in association with Delta cup since November 2002. 51 patients affected by CDH have been treated.

Clinical and radiographic results can be considered very good. The average evaluation based on Merle D'Aubigné schedule is equal to 17.5 with a significant increase in the results with respect to the preoperatory score (with an average score equal to 10).

In the light of the above, Modulus should be considered a valuable system to optimize the results of total hip replacement also in those more complex situations with a modified femoral morphology, allowing the restoration of a normal biomechanics in terms of off-set and anteversion with benefit in terms of stability and length of the implant as well as in terms of satisfaction of the patient as far as limb length and ROM are concerned.

The association of Modulus with big diameter heads gives a higher guarantee in terms of duration of the implant and restoration of the functionality in young patients with a serious deformity and increased functional demands.
The relationship of the orientation of the transverse acetabular ligament and acetabular labrum to the suggested safe zones of cup positioning in total hip arthroplasty
Authors: Archbold H.A.P. , Slomczykowski M. , Crone M. , Eckman K. , Jaramaz B. , Beverland D.E.
Published: January 2018

Background

There is a need to develop and validate a method for establishing cup orientation that is patient specific and independent of the anterior pelvic plane. It is our hypothesis that the transverse acetabular ligament and acetabular labrum can be used to do this. The objective of this study is to define the orientation of the plane formed by the transverse acetabular ligament and acetabular labrum and to examine whether these local landmarks lie within the limits of acceptance for cup positioning.

Methods

Twenty-five consecutive patients, who were being investigated for labral tears with a MRI arthrogram of the hip, were enrolled in this prospective study. The orientation of the transverse acetabular ligament-labrum plane was determined by manually selecting points on the transverse acetabular ligament and labrum. The best-fit plane through these points was determined and its operative orientation expressed with respect to a constructed pelvic coordinate system.

Results

The operative anteversion of the transverse acetabular ligament-labrum plane ranged from 5.3-36.1° (mean 23.0° ± 7.4° standard deviation). The inclination ranged from 38.4-50.3° (mean 45.6° ± 3.2° standard deviation).

Conclusions

The transverse acetabular ligament and acetabular labrum offer a possible solution to the many difficulties involved in cup placement during total hip arhroplasty This paper highlights the variation in the orientation of these local acetabular landmarks and questions the logic of a set target for cup positioning.
Acetabular version and long posterior wall cup in total hip replacement
Authors: Chandran P. , Azzabi M. , Lister A. , Andrews M. , Stone M.H.
Published: January 2018

This study discusses the definition of operative, anatomic and radiographic acetabular anteversion and their effect on a long posterior wall cup. In this cadaveric study, anteversion was modelled radiographically with a Charnley double wire marker Long Posterior Wall (LPW) cup and the position of the long posterior wall was studied with relation to different anteversion angles, and also correlated with computer generated line diagrams of the acetabular cup. The position of a long posterior wall varies when different types of anteversion are applied. By increasing the operative anteversion the long posterior wall comes to lie inferiorly and the advantage of the long posterior wall is lost. In light of prior confusion with definitions and in an attempt to make the terms more relevant to the surgical technique we propose the simplified alternate terms of ‘flexion-anteversion’ previously called ‘operative anteversion’, ‘internal rotation-anteversion’ previously called ‘anatomic anteversion’ and ‘combined anteversion’ previously called ‘radiographic anteversion’. If the surgeon elects to use LPW it is important to understand the effect of each type of anteversion on eventual position of the raised wall.
Porous tantalum uncemented acetabular shells in revision total hip replacement: Two to four year clinical and radiographic results
Authors: Kim W.Y. , Greidanus N.V. , Duncan C.P. , Masri B.A. , Garbuz D.S.
Published: January 2018

In cementless revision total hip arthroplasty (THA), achieving initial implant stability and maximising host bone contact is key to the success of reconstruction. Porous tantalum acetabular shells may represent an improvement from conventional porous coated uncemented cups in revision acetabular reconstruction associated with severe acetabular bone defects. We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects done with a hemispheric, tantalum acetabular shell and multiple supplementary screws. At a mean follow-up of 40 (24–51) months, one acetabular shell had been revised in a patient with a Paprosky 3B defect. Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent early clinical and radiographic results and warrants further evaluation in revision acetabular reconstruction associated with severe acetabular bone defects.
Cement as a locking mechanism for screw heads in acetabular revision shells – a biomechanical analysis
Authors: Laflamme G.Y. , Alami G.B. , Zhim F.
Published: January 2018

In acetabular revisions, polyethylene (PE) liners are often cemented into metal shells on top of acetabular screw heads. This study investigates the possibility of using this technique to obtain “fixed-angle” acetabular screws - a concept that has not yet been reported in the literature.

Two groups of screws (n=8) were inserted into Trabecular Metal revision shells (Zimmer), into which PE liners were then cemented. Screws in Group 1, inserted in the shell's pre-fabricated holes, were countersunk, whereas screws in Group 2 were inserted in custom-drilled holes that make their heads protrude into, and interdigitate with, the overlying cement mantle. Perpendicular loading was then applied to the screw shafts both statically to failure and cyclically.

A greater stiffness was observed for the protruding screws upon static loading; and while the countersunk screws all failed at the screw-cement junction (53.44 ± 8.33 N), the protruding screws all failed at the screw shaft (1049.79 ± 32.12 N) – a 20-fold difference (p < 0.05). Under cyclic loading, only the protruding screw head specimen did not fail, undergoing an overall displacement within the limits of osseointegration.

These results support the hypothesis that the protrusion of an acetabular screw head into an overlying cement mantle significantly increases its angular stability. Provided other variables are favorable, this “locking effect” may increase the initial stability of the whole implant, thus improving the ultimate success of complex acetabular revisions.
Ten-year results of a bone-preserving low-modulus composite total hip replacement stem
Authors: White S.P. , Lee M.B. , Galpin J. , Learmonth I.D.
Published: January 2018

A cementless composite femoral stem was developed with the aim of reducing bone loss secondary to stress shielding. Thirty-one stems were implanted in 27 patients, combined with a cementless acetabular component with polyethylene bearing surface in 30 cases and a bipolar head in 1 case. Patients were followed-up annually with clinical and radiographic evaluation. Fourteen hips underwent dual X-ray absorptiometry (DEXA) scans to monitor postoperative bone mineral density around the stem. The mean follow-up was 10.1 years. The mean Harris hip score improved from 57 to 92. To date, no stem has required revision. All stems are radiographically stable. Acetabular component revision has been required in 8 cases; 3 for liner dissociation and 5 for polyethylene wear. Radiographs and DEXA scans have shown some improvement in bone mineral density (BMD) between the 2 and 5-year follow-up. A cohort of patients displayed improvement in radiographic appearance and BMD in Gruen zone 7.

This stem shows evidence of proximal bone preservation and has excellent results at medium to long-term follow-up. The limiting factor in our cohort of patients has been the polyethylene bearing surface.
Validation Study of a Finnish Version of the Western Ontario and McMasters University Osteoarthritis Index
Authors: Soininen J.V. , Paavolainen P.O. , Gronblad M.A. , Kaapa E.H.
Published: January 2018

The aim of the study was to validate a Finnish version of the internationally used Western Ontario and McMasters University osteoarthritis index (WOMAC) questionnaire, by testing its reliability validity and responsiveness. The subjects of the study were patients scheduled for elective total knee arthroplasty (TKA) or total hip arthroplasty (THA). The patients completed the WOMAC questionnaire twice prior to surgery and once postoperatively to enable reliability construct validity and responsiveness analysis. Test-retest reliability could be calculated for 67 patients (37 TKA and 30 THA). The intraclass correlation coefficients (ICCa) exceeded 0.9 with the exception of the stiffness subscale which averaged 0.8. Correlation of the preoperative WOMAC total score with the Harris Hip Score (HHS) in 30 patients and American Knee Society Score (AKSS) in 37 patients were mediocre ranging from 0.48 to 0.53. To test responsiveness, the first preoperative and the postoperative WOMAC scores of 74 subjects were compared (41 TKA and 33 THA). Standard response means (SRM) and effect sizes (ES) exceeded the recommended score of 0.8, ranging from 1.15 to 2.35. In conclusion the Finnish translation of the WOMAC questionnaire performs as the original, is valid and can be used in future studies of osteoarthritis.
Medium-to-long Term DEXA Analysis of an Uncemented (AML) Femoral Component
Authors: Stöhr K.K. , Phillips C. , Healy J.C. , Al-Yassiri G. , Gibbons C.E.R.
Published: January 2018

We present medium-to-long-term bone mineral density studies assessing bone resorption and remodelling around the cementless femoral component of a total hip arthroplasty (Depuy AML prosthesis). Bone mineral densities were compared with the unoperated side at a time interval of eight years between scans using dual energy X-ray absorptiometry Initial proximal stress shielding is known but we show that this response continues into the medium to long term in relative terms. We have also found an overall trend for bone mineral density to increase around the prosthesis with the greatest changes occurring distally The greatest real increase in bone mineral density occurred in Gruen zones 2, 3 and 5 with smaller increases in zones 1, 4, 6 and 7. However, when compared with the contralateral unoperated femur (thus considering systemic changes in bone mineral density), we found these changes only reached statistical significance in Gruen zones 5, 6 and 7.
The use of LISS Femoral Locking Plates and Cabling in the Treatment of Periprosthetic Fractures around Stable Proximal Femoral Implants in Elderly Patients
Authors: Currall V. , Thomason K. , Eastaugh-Waring S. , Ward A.J. , Chesser T.J.S.
Published: January 2018

A retrospective review was performed of Vancouver type C periprosthetic femoral fractures treated using the Less Invasive Stabilisation System (LISS) femoral locking plate system. Five patients with stable hip prostheses (only one of which was an uncomplicated primary arthroplasty) were treated with the LISS plating system in combination with bone grafting and cables. The average age at the time of fixation was 87 years (range 83–93). All fractures united and all but one of the patients was able to mobilise independently. One case was complicated by superficial wound infection, but there were no other significant complications. One patient is still alive 50 months after surgery; the remaining four died a mean of 27 months postoperatively. Our results indicate that the LISS system is effective in the management of Type C periprosthetic fractures around well-fixed proximal femoral implants in the elderly, even in complex cases.
Revision of the Birmingham Hip Resurfacing cup: Technical notes and the use of a Novel Technique to Overcome Unique Problems
Authors: Sandiford N.A. , Kabir C. , Muirhead-Allwood S.K. , Skinner J. , Nuthall T.
Published: January 2018

The number of hip resurfacing procedures performed in the United Kingdom has doubled in the last four years reflecting its popularity among orthopaedic surgeons. Of the available options the Birmingham Hip Resurfacing (BHR) prosthesis has been the most popular choice in this country. Despite this revision rates have been shown to be higher in the resurfacing group compared to the total hip arthroplasty group particularly in the early postoperative period.

Revision of the BHR acetabular component is technically demanding due to several unique design features of this component. We discuss these features and describe a novel reliable and reproducible technique for revision of the BHR cup.
Rare Mode of Dynamic Hip Screw Failure
Authors: Khanna A. , Khanna A. , Parker M.
Published: January 2018

The sliding hip screw (SHS) has been the orthopaedic surgeon's implant of choice for repairing intertrochanteric femur fractures for nearly 30 years. Breakage of SHS is very rare and is seen mainly at the plate screw junction. Here we report a rare case of SHS failure; in this case the patient was asymptomatic after apparently uneventful fracture healing and the failure of SHS took place at the junction of barrel and screw.
Optimizing for Head Height, head Offset, and Canal Fit in a Set of Uncemented Stemmed Femoral Components
Authors: Khmelnitskaya E. , Mohandas P. , Walker P.S. , Muirhead-Allwood S.K.
Published: January 2018

When inserting an uncemented hip stem, the objectives are to obtain a close fit of the stem in the canal and anatomic head placement. Our goals were to formulate a set of stems which would satisfy these two objectives, and to test the resulting templates on sequential radiographs of hip replacement patients.

Using 98 cases for which a custom primary hip had been designed, thirteen dimensional parameters for a hip stem were defined, most importantly proximal medial width (PMW), proximal lateral width (PLW), head offset (HOF), head height (HHT), mid-stem diameter (BD), and distal diameter (DD). These parameters were analyzed in 155 patients' radiographs, and the resulting data were evaluated to obtain the optimal combinations of parameters. A 14–size stem system was defined and evaluated on the AP radiographs of 103 successive hip replacement patients.

For each stem diameter between 11 and 17mm, two pairs of PMW and PLW values, equivalent to ‘varus’ and ‘valgus’ shapes, provided the best fit for the population of radiographs. The template analysis showed that out of 103 cases, 93% of offsets were within 4mm of ideal, while 81% of heights were within 1mm of ideal, and 99% were within 4mm of the ideal. Canal fit was within 1.5mm in the proximal-medial Gruen Zone 7 in 58% of the cases.

The dimensional parameters of the 14 size system enabled the close matching of the important dimensional parameters simultaneously. The error that did occur could largely be corrected by modular heads and by minor canal broaching. By providing two stem shape variations for each stem diameter, our system achieved an accurate head center position while simultaneously obtaining a sufficiently close fit in the canal.
Assessment of Acetabular Retroversion following Long Term Review of Salter's Osteotomy
Authors: Robb Curtis A. , Datta Amit , Nayeemuddin Mohammed , Bache Christopher E.
Published: January 2018

Salter's innominate osteotomy may predispose to anterior over-coverage of the acetabulum. Over cover or retroversion has been demonstrated to be a cause of hip pain, impingement and subsequent osteoarthritis. We reviewed the long-term follow up of seventeen skeletally mature hips in sixteen patients who had previously undergone a Salter's osteotomy in childhood. The Salter pelvic osteotomy was performed at a mean average age of 5 years and follow up at a mean average age of 20 years. Patients were assessed by clinical examination for signs of impingement, Harris Hip Score and pelvic radiograph. Acetabular version was evaluated by the relationship between anterior and posterior walls of the acetabulum using templates applied to the pelvic radiograph as described by Hefti. The median acetabular cover averaged 17 degrees of anteversion with 2 patients (12%) demonstrating retroversion, neither of whom, had signs of impingement on examination. The mean average Harris Hip Score was 85 indicating a good outcome at long-term follow-up. We believe acetabular remodelling may occur with age after Salter's innominate osteotomy and have found good results in patients after skeletal maturation. Fears of long-term anterior over-coverage and retroversion with this operation may be unfounded.
Assessment of the Initial Stability of the Symax Femoral Stem with EBRA-FCA: A Multicentric Study of 85 Cases
Authors: Buratti Carlo Alberto , D'arrigo Carmelo , Guido Giulio , Lenzi Francesca , Logroscino Gian Domenico , Magliocchetti Giampiero , Mannocci Claudia , Patella Silvio , Patella Vittorio , Salvi Vittorio , Speranza Attilio , Speciale Domenico , Spinarelli Antonio , Topa Domenico
Published: January 2018

We report a study of 85 Symax femoral stems that were followed at regular intervals with radiographs at 6, 12, 24 and 36 months. The radiological migration of each stem was measured using the computer-assisted EBRA-FCA method. In 30 cases in which the EBRA method did not provide a complete measurement another computer-assisted method (Roman version 1.7) was employed. In all cases the distal migration of the stems was minimal, The threshold migration value used to define the stability of a stem was 1.5 mm at 24 months. The mean migration within the first two years was -0.17 mm (+/- 0.3) at 6 months, -0.31 mm (+/- 0.4) at 12 months and -0.45 mm (+/- 0.5) at 24 months. Only two cases exceeded the threshold limit of 1.5 mm at the two-year follow-up, but both values were lower than 2 mm. In the 25 cases which reached three-year follow-up the mean distal migration was -0.84 (+/-0.7). In four of them the subsidence exceeded 1.5 mm, but only one exceeded 2 mm. These data represent a positive predictive factor for the minimal risk of future aseptic loosening.
Idiopathic Transient Osteoporosis of the Pelvis in a Non-Pregnant Young Woman: A Case Study
Authors: Escolà Anna , Pons Miquel , Pasarín Alex , Majó Joan
Published: January 2018

Idiopathic transient osteoporosis of the hip is a rare condition that was first described in a series women in their third trimester of pregnancy. The clinical course is usually benign and self-limiting. Magnetic resonance is very useful for the diagnosis. Differential diagnoses include avascular necrosis of the femoral head, septic arthritis of the hip, osteomyelitis, stress fractures, primary or secondary neoplastic processes, and referred pain from the spine or genitourinary tract in pregnant women. The authors present a case of idiopathic transient osteoporosis of the pelvis in a young non-pregnant woman with insidious hip pain with no antecedent infection or trauma.
Salvage of a Hip following Pathological Fracture through a Large Aneurysmal Bone Cyst: A Case Report
Authors: Jun Xu , Chang-Qing Zhang
Published: January 2018

A young lady aged 20 presented to us in 2004 with a pathological fracture of the left femoral neck through a large aneurysmal bone cyst. Instead of total hip arthroplasty, we performed one-stage reconstruction surgery combining internal fixation and free vascularized fibular grafting. At 4 years the structure and function of the hip had been preserved.
Cemented Total Hip Arthroplasty in a Patient with α-Mannosidosis: A Case Report
Authors: Desai Aravind S. , Dramis Asterios , Board Timothy N. , Kay Peter R.
Published: January 2018

Mannosidosis is an extremely rare genetic disease occurring due to deficiency of the lysosomal enzyme, alpha-mannosidase. Patients with this disorder often suffer from musculoskeletal abnormalities and muscular weakness leading to joint destruction and severe morbidity along with other major systems involvement. We present here such a case of a 27-year-old male that highlights the challenges in management of hip joint destruction secondary to Mannosidosis.