title: Stress-related femoral cortical and cancellous bone density loss after collum femoris preserving uncemented total hip arthroplasty: a prospective 7-year follow-up with quantitative computed tomography Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study Prospective study of a cementless total hip arthroplasty with a collum femoris preserving stem and a trabeculae oriented pressfit cup: minimun 6-year follow-up Migration Pattern of a Short Femoral Neck Preserving Stem The Mayo Cementless Femoral Component in Active Patients with Osteoarthritis Bone sparing surgical options for total hip replacement. Medium Term Follow up of the Biodynamic Neck Sparing Prosthesis [Two-year results of a modular short hip stem prosthesis--a prospective study]. Learning Curve Analysis of the Collum Femoris Preserving Total Hip Surgical Technique [Periprosthetic bone loss after total hip endoprosthesis. Dependence on the type of prosthesis and preoperative bone configuration]. Stepwise introduction of a bone-conserving osseointegrated hip arthroplasty using RSA and a randomized study: II. Clinical proof of concept—40 patients followed for 2 years [Advantages of minimal invasive total hip replacement in the early phase of rehabilitation]. [Results after replacement of femoral neck prostheses - thrust plate prosthesis (TPP) versus ESKA cut prosthesis]. Leg length discrepancy, dislocation rate, and offset in total hip replacement using a short modular stem: navigation vs conventional freehand. [Periprosthetic femoral bone reaction after total hip arthroplasty with preservation of the collum femoris : CT-assisted osteodensitometry 1 and 3 years postoperatively].
abstract: Purpose Bone loss around uncemented femoral components is suspected to precede implant loosening and contribute to problems in revision surgery .  Short-stemmed cementless femoral components are design ed to preserve proximal femoral bone stock and ultimately the longevity of the prosthesis . Methods With quantitative computed tomography-assisted osteodensitometry , we prospect ively analyzed femoral cortical and cancellous bone density ( BD ) and contact area changes of an uncemented collum femoris preserving stem ( n = 38 ) 10 days , 1 , 3 and 7 years post-operatively . Results Seven years post-operatively  , cancellous BD ( mg CaHA/mL ) had decreased by as much as −66 % and cortical BD by up to −27 % at the metaphyseal portion of the femur ; the decrease was progressive between the 1- and 3-year examinations and halted thereafter . Contact area ( in % out of a possible 100 % ) decreased proximally between the 1- and 3-year follow-up . Conclusion Proximal cortical and cancellous bone density loss and decrease of contact area indicate that metaphyseal fixation can not be achieved . The lack of cortical BD loss and increase of contact area values below the trochanter minor suggest diaphyseal fixation Purpose On the basis of positive clinical results with mid- and long-term follow-up using the Mayo short stem , the Metha neck-preserving stem ( BBraun , Aesculap , Tuttlingen , Germany ) was introduced . The purpose of this study was to vali date the implant design by direct acquisition of bone remodelling data from total hip arthroplasty ( THA ) recipients using dual-energy X-ray absorptiometry ( DEXA ) . Methods After power analysis , 25 patients were included in this prospect i ve study . Patients were examined clinical ly and underwent DEXA examinations preoperatively and postoperatively at one week , six months and one and two years after THA . Gruen zones were adapted to the short stem design ( R1–R7 ) . Results The Harris Hip Score ( HHS ) increased significantly by 31 points . No stem had to be revised . Bone mineral density ( BMD ) in the greater trochanter decreased significantly from 0.78 g/cm2 postoperatively to 0.72 g/cm2 two years after surgery . Marginal changes were seen in the lateral distal regions ( R4–R5 ) . In the minor trochanter region , BMD increased significantly after two years by 12.9 % . In the calcar region , BMD exceeded the baseline value by 6.1 % two years after implantation . Conclusions Stress shielding seems to occur at the greater trochanter due to the vast cross-section of the implant . However , the aim of proximal load transfer of the Metha stem seems to be partially achieved . DEXA analysis revealed a concentrated load distribution on the medial portion of the femur , which is an important region to guarantee long-term implant survival Aim Tissue sparing hip prostheses are becoming more and more popular especially for the treatment of younger patients . The objective of this study was to evaluate the clinical and radiological results after insertion of a tissue sparing hip prosthesis . Method In 47 consecutive non-selected patients ( 50 hips ) , the clinical and radiographic results of cementless total hip arthroplasty using a collum femoris preserving stem , a pressfit cup and an alumina – polyethylene pairing were prospect ively evaluated . The mean age at index-surgery was 58 ( 36–82 ) years , there were 38 women and 9 men . After a mean follow-up of 6.8 years ( minimum 6.1 years ) , two patients had died and one patient underwent revision surgery due to aseptic loosening of the stem . Results The overall survival rate of the acetabular component was 100 % and of the femoral component 98 % . The mean Harris hip score at follow-up was 94 points . Conclusion The mid-term survival with this type of total hip arthroplasty is excellent and compares equal with uncemented straight stems in this age group The CFP stem represents a short collared neck-retaining stem with very proximal metaphyseal anchoring along the calcar combined with up-to- date metallurgy . Despite theoretical advantages , the stability and clinical outcome are unknown . We prospect ively measured the migration pattern of this new stem and cup . Twenty-six patients ( 26 hips ) with a mean age of 54 years ( range , 40 - 66 years ) underwent THA  and were followed for 2 years with  radiostereometry , radiographs , and clinical scores . The stem showed some early retroversion ( mean , SEM 0.6 ° , 0.3 ) , but stabilized before 1 year . Subsidence ( 0.05 mm , 0.06 ) and varus-valgus tilting ( 0.03 ° , 0.01 ) were low . We observed no bone loss in the calcar region . Factors related to patients , implant design , and implantation did not predict migration patterns . The two-dimensional wear of the ceramic/conventional articulation was 0.09 mm at 2 - 24 months . The low migration of this short neck preserving stem suggests a favorable long-term outcome but longer followup is needed to substantiate this prediction . This design might become an alternative to st and ard stems and hip resurfacing . Level of Evidence : Therapeutic Level IV . See The Guidelines for Authors for a complete description of levels of evidence This prospect i ve study reports the clinical and radiological results of a single-surgeon series using the Mayo conservative hip stem in a district hospital . 30 total hip arthroplasties were performed in 26 physically active patients . There were 18 women and 8 men , with a mean age of 57.4 years ( range 36–79 ) . 4 cases were bilateral . The operation was performed for severe primary or secondary osteoarthritis of the hip . Duration of follow-up ranged from 67–87 months ( mean 81 months ) . There were no early complications relating to the surgical procedure . There was one case of traumatic fracture of the femur during rehabilitation , while late complications included two cases of late infection ( 4 months and 16 months after surgery ) both revised in two-stage procedures . There was considerable improvement in Merle d'Aubigne score following surgery . There were no revisions for aseptic loosening , but we identified 2 implants with significant radiolucent lines and subsidence six years after the index operation . Neither patient experienced pain in the hip or restriction of activity . Therefore , the aseptic loosening survival rate was 100 % ( end point = revision operation ) . Taking radiological loosening as the end point survivorship was 93.3 % . The use of the Mayo short stem component in active patients may preserve bone and enable subsequent revision operations to proceed using primary implants . Our results suggest that conservative design s of this type may be of benefit in selected individuals Between 4/5/99 and 5/20/2002 , our university performed 31 total hip arthroplasties in 27 young patients utilizing a conservative hip prosthesis developed at the Mayo Clinic . Eleven patients underwent Bipolar replacement , while the remaining twenty required an acetabular component . The patients ranged in age from 25 to 50 ( mean of 39.9 ) . The mean follow up was 12.4 months ( range 4.5 - 27 ) . Twenty-eight hips were treated for AVN secondary to RA , HIV , ETOH abuse , and SLE ; while two underwent THA for OA secondary to trauma , and one for JRA . Three patients were lost to follow up at less than 6 months and were excluded from the study . The patients were followed for a minimum of 6 months utilizing the  Harris hip score  , the  Charnley hip score  , and  radiographic evaluation including subsidence , radiolucency , and calcar resorption . Four patients ( 13 % ) had subsidence ranging from 1 to 3 mm at the most recent visit . One patients ( 3.2 % ) had radiographic evidence of radiolucency measuring 2 mm . Nine patients ( 29 % ) developed 1 - 3 mm of calcar resorption . No hips required revision . Thirty patients had improvement in their Harris hip score and Charnley hip score . The one patient who decreased his score had developed AVN secondary to ETOH abuse . Three hips had an intra-operative complication of lateral cortex penetration and required circlage wiring . Comparisons were made utilizing Multiple Logistic Regression to determine if preoperative BMI , Dorr score , and gender had an impact on the postoperative hip scores or degree of osteolysis , subsidence , and calcar resorption . Although the Harris hip score and Charnley hip scores significantly improved postoperatively , the preoperative BMI , Dorr score , and gender did not correlate with patient outcome . Our patients improved clinical ly in pain level , function and ROM . Further follow up will reveal if this component truly preserves bone stock for ease of future revision Hip resurfacing ( HR ) and neck sparing prostheses ( NSP ) have been advocated for the treatment of arthritis in younger patients . Some complications following HR have been documented in the recent literature , but NSP are not yet supported by clinical follow-up studies of sufficient duration . We present an assessment of the neck sparing “ Biodynamic ” prosthesis .  153 patients were evaluated in a longitudinal cohort prospect i ve study , with survival analysis , clinical score and radiographic assessment of stability and osteointegration at 41.8 months average follow up . Survival and clinical outcome were similar to most traditional prostheses in the literature . On radiographic analysis we recorded good neck preservation and osteointegration . Only two stem failures were recorded . Poor clinical outcome was related to misalignment of prostheses implanted during the ‘ learning curve ’ . The NSP system described may be a good alternative to HR for younger patients . The system is characterized by good survival and clinical and radiographic outcome combined with bone stock preservation AIM The short-term results of a prospect i ve , consecutive series of 50 cementless modular short hip stem endoprostheses  are reported . METHOD 48 cases were available for clinical and radiological follow-up at an average time of 2.4 years post-op . One patient did not consent to a follow-up investigation , 1 early revision was necessary 4 weeks post-op after a fall precipitating a periprosthetic fracture . RESULTS The average age at the time of THA was 54 years and the Harris hip score reached 95 points at the time of follow-up . One implant had aseptic loosening and 1 implant was revised due to a failure of the modular titanium neck adapter . An equal number of patients received modular neck adapters with neutral or 7.5 degrees retroversion . No 140 degrees neck and no anteverted neck adapters were used . Radiological results of the 2/3 porous coated hip stem showed a metaphyseal bone remodelling with hypertrophies in coated Gruen zones 3 ( 17 % ) and 6 ( 46 % ) and marked spot welds and increased bone density ( 86 % ) in the distal area of the coating . Primary implant migration between 2 and 10 mm was present in 7 cases due to a low osteotomy and implant position combined with an implant undersizing and lack of proximal-lateral support . At the time of the last follow-up these cases had no clinical symptoms with an average HHS of 96 points and with full bony integration . CONCLUSION Our results support the use of the investigated short hip stem for THA when the femoral bone quality and morphology support the metaphyseal anchoring concept . The surgical technique must avoid a stem position without proximal-lateral cortical contact to the femoral osteotomy , as this reduces primary implant stability . Further follow-up is necessary to vali date the long-term success of this procedure The aim of this study was to determine whether  femoral neck preserving total hip arthroplasty  would become less difficult and more efficient during the first 20 cases and to identify potential pitfalls during the introduction of this procedure . The difficulty and efficiency of the initial 20 procedures performed by four surgeons was prospect ively determined by analysing a total of 68 video recordings using time-action analysis . This method measures the duration and efficiency of individual actions needed for a surgeon to achieve his or her goal . Afterwards , we review ed all actions with a long duration and discussed possible causes of delay with the surgeons to identify possible pitfalls . We found a decrease of difficulty and an increase of efficiency during the first 20 cases and a more consistent execution after the initial five cases . Estimating the correct osteotomy level and stem curvature was often difficult , which result ed in a variable stem position . Radiologic analysis demonstrated a tendency for varus position and increased leg length throughout the series , even after the surgeons demonstrated technical proficiency The changes of the periprosthetic bone density were examined with DEXA in 81 patients over a period of 1 year after implantation of cementless total hip endoprosthesis . Four types of endoprostheses ( Vision 2000/Duraloc , ALPHA-Fit/ALPHA-Lock Plus , CLS/Allofit , Mayo/Trilogy ) were implanted . Information on the changes of the periprosthetic bone density depending on the type of the prosthesis and the bony situation at the femur before operation was expected from these measurements . In all types of stems the strongest reduction of the bone density was found in the region of the calcar femoris , and the smallest changes were found distally and medially of the tip of the prostheses . In the prosthesis with shorter stem the change of the bone density was altogether clearly lower than in prostheses with longer stem . With increasing size of the prosthesis with proximally porous coating made from cobalt-chrome alloy , proximal atrophy was observed more frequently , whilst in the prosthesis made from titanium alloy with completely rough-blasted surface the distal hypertrophy increased . A low preoperative corticalis-bone marrow index strengthened the proximal atrophy in proximally porously coated prosthesis made from cobalt-chrome alloy and led in the prosthesis with completely rough-blasted surface more often to distal hypertrophy of the bone Background We have developed a bone-conserving commercially pure titanium hip replacement system using osseointegration principles : a metaphyseal loading proximal femoral component affixing into the retained neck and metaphysis only , leaving the femoral canal untouched . The acetabular cup closely fits a dual-geometry cavity , avoiding stress protection at the dome . Patients and methods After extensive laboratory and clinical pilot trial investigations , the surface-engineered implants were su bmi tted to a prospect i ve r and omized controlled clinical trial involving 40 patients ( 40 hips ) , in which they were compared to the cemented Spectron femoral component and cementless Trilogy cup as control implant . The following clinical measures were used to monitor progress at regular intervals for the first 2 postoperative years : radiostereometric analysis ( RSA ) , Harris Hip Score , pain score , WOMAC , and SF-36 . Results After 2 years of follow-up , no statistically significant differences were seen between the groups concerning rotation or translation along the cardinal axes . The patients receiving the Gothenburg osseointegrated titanium ( GOT ) system had significantly higher Harris Hip Score at 6 months , suggesting more rapid recovery . WOMAC , SF-36 and pain analysis were similar for the first 2 postoperative years . Interpretation Our RSA data suggest that osseointegration was achieved for all patients receiving the GOT hip system . This bone-conserving prosthesis may provide a good alternative , especially for young and active patients UNLABELLED In arthroplasty the term " minimal invasive " not only refers to the length of the skin incision but more so to its soft tissue and thereby muscle-protecting features . STUDY AIM The aim of this study is to compare the early postoperative mobilisation and rehabilitation of the different surgical approaches in cementless total hip arthroplasty . METHODS 27 patients underwent a total hip replacement ( Trilogy cup , MAYO stem ) via a ventral minimal invasive approach ( one incision technique ) ( MIS group ) . 23 patients underwent a total hip replacement with the same implant via a anterolateral transgluteal approach ( st and ard group ) . We evaluated the Harris Hip Score ( HHS ) , the visual analogue scale ( VAS ) for pain and patient satisfaction preoperatively as well as 3 days , 10 days , 6 weeks and 3 months postoperatively . RESULTS After 3 and 10 days the MIS group showed better scores for pain , gait and mobilisation as well as for the overall HHS compared to the st and ard group . These differences could not be shown 6 weeks postoperatively . The MIS group had a significantly higher rate of complications with 22 % transient impairment of the lateral cutaneous nerve . CONCLUSION The patients of the MIS group showed a better mobilisation and rehabilitation during the early postoperative period . This can be attributed to the lessened intraoperative damage of to soft tissue and especially muscle damage . Due to the increased rate of nerve irritations , we modified our surgical approach . The minimal invasive approach to modern hip joint arthroplasty remains a non-st and ard technique . Compared to the st and ard approach it carries additional risks ( like nerve damage and malpositioning of the implants and thus should remain in the h and s of the experienced orthopaedic surgeon in specialised orthopaedic centres AIM The aim of this study was to analyse and evaluate comparatively loosening mechanisms , failure frequency , surgical changing strategies and results after replacement of  thrust plate prostheses ( TPP ) and ESKA Cut prostheses . METHOD Between 1993 und 2007 , 465 TPP and in the years 2000 and 2001 82 ESKA Cut prostheses were performed and evaluated prospect ively . Until 2007 46 change interventions of the TPP and 35 of the CUT prosthesis became necessary . All patients who received a stem revision procedure in our hospital were included within this study . Besides the evaluation of clinical results according to the criteria of the Harris Hip Score on the average at 15.6 months ( + /- 14.4 ) postoperatively , radiological loosening processes and surgical difficulties were registered . Furthermore , an analysis of perioperative data was performed according to some criteria of the German Federal Office of Quality Assurance ( BQS ) , such as duration of the surgery , intraoperative blood loss and complications . Statistical investigations for comparative analysis as well as survival analysis of both groups were calculated using SPSS for Windows 13.0 . RESULTS The mean age of the 46 patients who had to undergo revision surgery after TPP was 60.1 years , that of 35 patients in whom revision surgery was necessary after receiving an ESKA Cut femoral neck stem was 56.6 years . The survival rate analysis according to Kaplan-Meier at 13 years was 89.4 % ( TPP ) and 53.6 % at 66 months ( ESKA Cut ) . In all cases the partial osteointegration of the tripod surface of the loosened Cut prosthesis complicated the explantation . It led on the one h and to a significant difference of the surgery duration and on the other h and to an increased frequency of fractures of the trochanteric region . The conversion of the TPP on st and ard type stems was usually free of problems . The HHS increased significantly to the averages of 86.6 ( TPP ) or , respectively , 91.69 ( ESKA Cut ) after revision . CONCLUSION In comparison with the usually problem-free changing procedure of the TPP to a st and ard type stem , the revision surgery of the Cut prosthesis becomes substantially more complex and leads frequently to complications . In view of unacceptable survival rates , the Cut prosthesis does not represent an alternative implant in young patients . Except for the implantation technique , which does not allow a less invasive surgical procedure , the TPP fulfils the requirements of femoral neck prosthesis due to acceptable survival rates and good convertibility We present a match-paired study between computer-assisted and freeh and techniques using a short modular femoral stem ( Metha ; B. Braun Aesculap , Tuttlingen , Germany ) in  total hip replacement ( THR ) .  Surgical time , clinical outcome , dislocation rate , limb length , and offset in 44 patients with ideal indication for this more conservative implant were assessed . Despite both longer surgical time and similar early outcomes , the results showed how computer-assisted techniques allow easier management of limb length discrepancy and offset restoring . We believe that navigated short modular stems are safe for less invasive THR BACKGROUND Short-stemmed cementless femoral components in total hip arthroplasty have been design ed to preserve the proximal femoral bone stock by load transfer to the femoral metaphysis . An in vivo method of computed tomography-assisted ( CT ) osteodensitometry after total hip arthroplasty is presented which differentiates between cortical and cancellous bone density ( BD ) changes around uncemented femoral components . PATIENTS AND METHODS Cortical and cancellous periprosthetic femoral BD ( mg Ca HA/ml ) was determined prospect ively in 31 patients at day 10 , 1 year and 3 years after total hip arthroplasty with preservation of the collum femoris ( C.F.P.-stem , Link , Hamburg , Germany ) using computed tomography-assisted osteodensitometry .  Clinical results ( Harris hip score ) and plain x-rays were assessed in all cases . RESULTS Progressive proximal cortical BD loss was observed between the 1 year ( Ø -8 % ) and 3 year ( Ø -22 % ) postoperative measurements . Distal to the trochanter minor no significant cortical BD changes were observed . Proximal cancellous BD decreased progressively between the 1 year ( Ø -33 % ) and 3 year ( Ø -45 % ) analyses . The Harris hip score improved from 45 points pre-operatively to 93 points at the 3 year follow-up . All x-rays showed signs of stable ingrowth . CONCLUSION Periprosthetic CT osteodensitometry has the technical ability to discriminate between cortical and cancellous bone structures with respect to strain-adapted remodeling . Progressive proximal cortical and cancellous BD loss indicates that metaphyseal fixation can not be achieved with the analyzed C.F.P. stem design . The lack of cortical BD loss below the trochanter minor suggests diaphyseal fixation of the implanted stem
target: These studies did not show a satisfactory overall survival rate
background: Background and purpose The aim of short-stem total hip arthroplasty is to preserve proximal bone stock for future revisions , to improve biomechanical reconstruction , and to make minimally invasive approaches easier .
  It is therefore being increasingly considered to be a sound alternative to conventional total hip arthroplasty , especially for young and active patients .
  However , it is still unknown whether survival rates of short-stem  hips match current st and ards .
  We made a systematic summary of reported overall survival after short-stem total hip arthroplasty .