Which approach of total hip arthroplasty is the best efficacy and least complication?

BACKGROUND Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function.Approaches of the hip have been exhaustively explored about pros and cons.The efficacy and the complications of hip approaches remains inconclusive.This study conducted an umbrella review to systematically appraise previous meta-analysis(MAs)including conventional posterior approach(PA),and minimally invasive surgeries as the lateral approach(LA),direct anterior approach(DAA),2-incisions method,mini-lateral approach and the newest technique direct superior approach(DSA)or supercapsular percutaneouslyassisted total hip(SuperPath).AIM To compare the efficacy and complications of hip approaches that have been published in all MAs and randomized controlled trials(RCTs).METHODS MAs were identified from MEDLINE and Scopus from inception until 2023.RCTs were then updated from the latest MA to September 2023.This study included studies which compared hip approaches and reported at least one outcome such as Harris Hip Score(HHS),dislocation,intra-operative fracture,wound compliData were independently selected,extracted and assessed by two reviewers.Network MA and cluster rank and surface under the cumulative ranking curve(SUCRA)were estimated for treatment efficacy and safety.RESULTS Finally,twenty-eight MAs(40 RCTs),and 13 RCTs were retrieved.In total 47 RCTs were included for reanalysis.The results of corrected covered area showed high degree(13.80%).Among 47 RCTs,most of the studies were low risk of bias in part of random process and outcome reporting,while other domains were medium to high risk of bias.DAA significantly provided higher HHS at three months than PA[pooled unstandardized mean difference(USMD):3.49,95%confidence interval(CI):0.98,6.00 with SUCRA:85.9],followed by DSA/SuperPath(USMD:1.57,95%CI:-1.55,4.69 with SUCRA:57.6).All approaches had indifferent dislocation and intraoperative fracture rates.SUCRA comparing early functional outcome and composite complications(dislocation,intra-operative fracture,wound complication,and nerve injury)found DAA was the best approach followed by DSA/SuperPath.CONCLUSION DSA/SuperPath had better earlier functional outcome than PA,but still could not overcome the result of DAA.This technique might be the other preferred option with acceptable complications.

Dislocation of primary total hip arthroplasty:Analysis of risk factors and preventive options

Total hip arthroplasty(THA)is one of the most successful elective operations in orthopedic surgery for improving pain and functional disability in patients with end-stage joint disease.However,dislocation continues to be a troublesome complication after THA,as it is a leading cause of revision and is associated with substantial social,health,and economic costs.It is a relatively rare,usually early occurrence that depends on both the patients’characteristics and the surgical aspects.The most recent and important finding is the special attention to be given preoperatively to spinopelvic mobility,which is closely related to the incidence of dislocation.Consequently,clinical and radiographic assessment of the lumbar spine is mandatory to identify an altered pelvic tilt that could suggest a different positioning of the cup.Lumbar spinal fusion is currently considered a risk factor for dislocation and revision regardless of whether it is performed prior to or after THA.Surgical options for its treatment and prevention include the use of prostheses with large diameter of femoral head size,dual mobility constructs,constrained liners,and modular neck stems.

Total hip arthroplasty for sequelae of childhood hip disorders:Current review of management to achieve hip centre restoration

Adults requiring total hip arthroplasty(THA)for childhood disorder sequelae present with shortening,limp,pain,and altered gait.THA,which can be particularly challenging due to altered anatomy,requires careful planning,assessment,and computed tomography evaluation.Preoperative templating is essential to establish the appropriate acetabular and femoral size.Information regarding neck length and offset is needed to ensure the proper options are available at THA.Hip centre restoration must be planned preoperatively and achieved intraoperatively with appropriate exposure,identification,and stable fixation with optimum-size components.Identifying the actual acetabular floor is essential as changes include altered anatomy,distortion of the margins and version changes.Proximal femur changes include anatomical variation,decreased canal diameter,cortical thickness,changes in anteversion,and metaphyseal and diaphyseal mismatch.Preoperative assessment should consist of limb assessment for variations due to prior surgical procedures.Evaluation of the shortening pattern with the relationship of the lesser trochanter to the teardrop would help identify and plan for subtrochanteric shortening osteotomy,especially in high-riding hips.The surgical approach must ensure adequate exposure and soft tissue release to achieve restoration of the anatomical hip centre.The femoral components may require modularity to enable restoration of anteversion and optimum fixation.

Mortality rate after total knee arthroplasty or total hip arthroplasty in patients with a history of liver transplant

In this editorial I comment on the article by Ahmed et al published in a recent issue of the World J Orthop 2023;14:784-790.It is well known that patients who have undergone a liver transplant(LT)may need to have a total hip arthroplasty(THA)or total knee arthroplasty(TKA)implanted.Ahmed et al stated that the mortality rate in these patients was similar to the one of the general population.However,there are three articles previously published that found higher mortality in LT patients who experienced THA/TKA than in the general population(individuals without LT).Therefore,in this Editorial I would like to point out that there is controversy in the literature regarding whether LT patients undergoing THA/TKA have higher mortality than the general population.Therefore,future research should attempt to resolve this controversy.

Offset restoration in total hip arthroplasty:Important:A current review

Normal vertical and horizontal offset is essential for hip biomechanics,muscle functioning and gait pattern.Total hip arthroplasty(THA)should aim to restore normal offset with implantation of femoral and acetabular components.This would be possible with proper preoperative planning,templating and ensuring implant options are available for offset restoration.Templating is essential for understanding the vertical and horizontal offset change,especially in hip arthritis presenting late with significant limb length discrepancy at THA.Planning should include appropriate soft tissue releases and the use of ideal implants to achieve restoration of horizontal and vertical offset.Under correction of horizontal offset at THA for fracture neck of femur could result in abductor fatigue,limp and increased wear.Restoration of horizontal offset is imperative at THA for a fractured neck of the femur to achieve optimal abductor function.Horizontal offset is necessary for optimal abductor muscle tension and function.Revision THA for acetabular bone loss would require hip center restoration with the acetabular and femoral offset correction to achieve limb length correction and abductor length.The inability to achieve vertical and horizontal offset correction could lead to dislocation or signs of abductor fatigue.Careful vertical and horizontal femur offset restoration is required for normal hip biomechanics,decreased wear and increased longevity.

Total hip arthroplasty preoperative planning for childhood hip disorders’sequelae:Focus on developmental dysplasia of the hip

Developmental dysplasia of the hip(DDH)poses significant challenges in both childhood and adulthood,affecting up to 10 per 1000 live births in the United Kingdom and United States.While newborn screening aims to detect DDH early,missed diagnoses can lead to severe complications such as hip dysplasia and early onset osteoarthritis in adults.Treatment options range from less invasive procedures like hip-preserving surgery to more extensive interventions such as total hip arthroplasty(THA),depending on the severity of the condition.Preoperative planning plays a critical role in optimizing surgical outcomes for DDH patients undergoing THA.This includes accurate imaging modalities,precise measurement of acetabular bone stock,assessment of femoral head subluxation,and predicting prosthesis size and leg length discrepancy.Recent advancements artificial intelligence and machine learning offer promising tools to enhance preoperative planning accuracy.However,challenges remain in validating these technologies and integrating them into clinical practice.This editorial highlights the importance of ongoing research to refine preoperative strategies and improve outcomes in DDH management through evidence-based approaches and technological innovations.

Specific approach to total hip arthroplasty in patients with childhood hip disorders sequelae

Hip arthroplasty in patients with a history of paediatric hip disorders presents a significant challenge for orthopaedic surgeons.These patients are typically younger and have greater functional demands.Therefore,achieving optimal biomechanical conditions is crucial,involving placement of the acetabulum at the ideal centre of rotation and securing a stable femoral component with good offset to preserve abductor muscle function and restore leg length.The altered anatomy in these cases makes total hip arthroplasty more complex,necessitating thorough preoperative imaging and an individualised surgical approach.Various techniques may be employed to optimise biomechanical outcomes.We propose a modified lateral hip approach,offering exceptional visualisation of the acetabulum and femur while preserving the continuity of the abductor muscles without requiring trochanteric osteotomy.To achieve the most biomechanically advantageous acetabular position,cotyloplasty is our preferred method.

Intraoperative application of three-dimensional printed guides in total hip arthroplasty: A systematic review

BACKGROUND Acetabular component positioning in total hip arthroplasty(THA)is of key importance to ensure satisfactory post-operative outcomes and to minimize the risk of complications.The majority of acetabular components are aligned freehand,without the use of navigation methods.Patient specific instruments(PSI)and three-dimensional(3D)printing of THA placement guides are increasingly used in primary THA to ensure optimal positioning.AIM To summarize the literature on 3D printing in THA and how they improve acetabular component alignment.METHODS PubMed was used to identify and access scientific studies reporting on different 3D printing methods used in THA.Eight studies with 236 hips in 228 patients were included.The studies could be divided into two main categories;3D printed models and 3D printed guides.RESULTS 3D printing in THA helped improve preoperative cup size planning and post-operative Harris hip scores between intervention and control groups(P=0.019,P=0.009).Otherwise,outcome measures were heterogeneous and thus difficult to compare.The overarching consensus between the studies is that the use of 3D guidance tools can assist in improving THA cup positioning and reduce the need for revision THA and the associated costs.CONCLUSION The implementation of 3D printing and PSI for primary THA can significantly improve the positioning accuracy of the acetabular cup component and reduce the number of complications caused by malpositioning.

Effects of ulinastatin combined with dexmedetomidine on cognitive dysfunction and emergence agitation in elderly patients who underwent total hip arthroplasty

BACKGROUND With the continuous growth of the modern elderly population,the risk of fracture increases.Hip fracture is a common type of fracture in older people.Total hip arthroplasty(THA)has significant advantages in relieving chronic pain and promoting the recovery of hip joint function.AIM To investigate the effect of ulinastatin combined with dexmedetomidine(Dex)on the incidences of postoperative cognitive dysfunction(POCD)and emergence agitation in elderly patients who underwent THA.METHODS A total of 397 patients who underwent THA from February 2019 to August 2022.We conducted a three-year retrospective cohort study in Shaanxi Provincial People’s Hospital.Comprehensive demographic data were obtained from the electronic medical record system.We collected preoperative,intraoperative,and postoperative data.One hundred twenty-nine patients who were administered Dex during the operation were included in the Dex group.One hundred fifty patients who were intravenously injected with ulinastatin 15 min before anesthesia induction were included in the ulinastatin group.One hundred eighteen patients who were administered ulinastatin combined with Dex during the operation were included in the Dex+ulinastatin group.The patients’perioperative conditions,hemodynamic indexes,postoperative Mini-Mental State Examination(MMSE)scores,Ramsay score,incidence of POCD,and serum inflammatory cytokines were evaluated.RESULTS There was a significant difference in the 24 h visual analogue scale score among the three groups,and the score in the Dex+ulinastatin group was the lowest(P<0.05).Compared with the Dex and ulinastatin group,the MMSE scores of the Dex+ulinastatin group were significantly increased at 1 and 7 d after the operation(all P<0.05).Compared with those in the Dex and ulinastatin groups,incidence of POCD,levels of serum inflammatory cytokines in the Dex+ulinastatin group were significantly decreased at 1 and 7 d after the operation(all P<0.05).The observer’s assessment of the alertness/sedation score and Ramsay score of the Dex+ulinastatin group were significantly different from those of the Dex and ulinastatin groups on the first day after the operation(all P<0.05).CONCLUSION Ulinastatin combined with Dex can prevent the occurrence of POCD and emergence agitation in elderly patients undergoing THA.

Primary Total Hip Arthroplasty on Complex Hips Conditions in a Low-Resource Setting

Introduction: Total hip arthroplasty of complex morphology is a challenge for the orthopaedic surgeon. Careful analysis of the hip’s anatomy helps to unravel the difficulties and anticipate the procedures to be performed and the implants to be planned. The aim was to identify the types of hip that make first-line THR difficult, specify the technical procedures to be used on these sites, and assess the functional results of the series. Material and Methods: This was a retrospective study that concerned patients operated on for total hip arthroplasty between January 2015 and December 2022 at the medical center “La Grâce” in Bobo-Dioulasso, Burkina Faso. Patients with coxarthrosis (on hip dysplasia, acetabular protrusio, acetabular malunion or neurological hip) and those with ankylosis of the hip, osteonecrosis secondary to neglected dislocation of the hip or hemoglobinopathy were included. Results: A total of 31 total hip replacements were performed in 30 patients. The mean age of patients at the surgery time was 36.2 years with extremes of 17 and 61 years. The male-to-female sex ratio was 1. The main indications for THA were the dysplasic hip osteoarthritis (11 cases) and the neglected hip dislocations (7 cases). In situ femoral neck osteotomy before hip dislocation was performed in seven cases. The acetabulum reconstruction techniques varied from the structural iliac bone graft (n = 3) and cancellous bone graft (n = 4) to the Kerboull plate (n = 1). After 45 months of mean follow-up, all hips were evaluated. The mean PMA score increased from 7.1 [4 - 8] before the surgery to 13.2 [13 - 17]. Conclusion: The large spectrum of challenges in complex hip management requires effective preoperative planning. Preoperative planning minimizes complications and ensures a better outcome.

Technical note for intraoperative determination of proper acetabular cup size in primary total hip arthroplasty

BACKGROUND Selecting the optimal size of components is crucial when performing a primary total hip arthroplasty.Implanting the accurate size of the acetabular component can occasionally be exacting,chiefly for surgeons with little experience,whilst the complications of imprecise acetabular sizing or over-reaming can be potentially devastating.AIM To assist clinicians intraoperatively with a simple and repeatable tip in elucidating the ambivalence when determining the proper acetabular component size is not straightforwardly achieved,specifically when surgeons are inexperienced or preoperative templating is unavailable.METHODS This method was employed in 263 operations in our department from June 2021 to December 2022.All operations were performed by the same team of joint reconstruction surgeons,employing a typical posterior hip approach technique.The types of acetabular shells implanted were:The Dynasty®acetabular cup system(MicroPort Orthopedics,Shanghai,China)and the R3®acetabular system(Smith&Nephew,Watford,United Kingdom),which both feature cementless press-fit design.RESULTS The mean value of all cases was calculated and collated with each other.We distinguished as oversized an implanted acetabular shell when its size was>2 mm larger than the size of the acetabular size indicator reamer(ASIR)or when the implanted shell was larger than 4 mm compared to the preoperative planned cup.The median size of the implanted acetabular shell was 52(48–54)mm,while the median size of the preoperatively planned cup was 50(48–56)mm,and the median size of the ASIR was 52(50–54)mm.The correlation coefficient between ASIR size and implanted acetabular component size exhibited a high positive correlation with r=0.719(P<0.001).Contrariwise,intraoperative ASIR measurements precisely predicted the implanted cups’size or differed by only one size(2 mm)in 245 cases.CONCLUSION In our study,we demonstrated that the size of the first acetabular reamer not entering freely in the acetabular rim corroborates the final acetabular component size to implant.This was also corresponding in the majority of the cases with conventional preoperative templating.It can be featured as a valid tool for avoiding the potentially pernicious complications of acetabular cup over-reaming and over-sizing in primary total hip arthroplasty.It is a simple and reproducible technical note useful for confirming the predicted acetabular cup size preoperatively;thus,its application could be considered routinely,even in cases where preoperative templating is unavailable.

Biodegradation of Polymethylmethacrylate Bone Cement May Not Be a Serious Issue in Total Hip Arthroplasty—Retrieval Study for Knoop Hardness and Young’s Modulus

Introduction: To investigate a long-term in vivo deterioration of polymethylmethacrylate (PMMA) bone cement over time, we evaluated retrieved PMMA cement in terms of chemical elements presenting in the cement using energy dispersive analysis of X-rays;Knoop hardness;and the Young’s modulus using scanning acoustic microscopy. Materials and Methods: For mechanical evaluation, we could neglect the influences of entrapped air bubbles or blood by the use of small specimens. The study was based on thirteen cement samples (six used in the acetabulum and seven in the femur) derived from eight patients (age at revision surgery: mean 72.5, range 68 to 79). All of these samples were Simplex-P?cement. They were functioning well at least ten years after the previous surgery. Duration until revision surgery was ranged 12 to 25 years (average, 17.4 years). The reason for revision was aseptic mechanical loosening. Twenty samples of Simplex-Preg;cement were served by manually mixing as a control. Results: The average of the hardness of the cement was 17.0 ± 1.2 (range, 13.4-20.6). In the control, the hardness was 17.8 ± 1.5 (range, 14.0-24.6). There was no significant difference between these values. The mean of Young’s modulus of the cement was 5.61 ± 0.19 GPa (range, 5.09-6.10). In the control, the modulus was 6.04 ± 0.13 GPa (range, 5.68-6.45). Although the modulus was significantly less than that of the control, there was only 7% decrease in average between twelve and twenty-five years in vivo. Conclusions: Our results suggest that long-term implantation and functional loading in vivo may not be the limiting factor in the mechanical integrity of the bone cement.

CEMENTLESS TOTAL HIP ARTHROPLASTY IN PATIENTS OLDER THAN 70 YEARS

Objective To present 3-15 years follow-up of patients older than 70 years who underwent cementless total hip arthroplasty. Methods One hundred and two consecutive primary total hip arthroplasties utilizing a circumferential proximal porous coated femoral component and smooth surfaced threaded acetabular were performed in 92 patients. The patients were followed up clinically and radiographically every two years from their third year after surgery. Ten patients (10 hips) died and 14 patients (15 hips) were lost to follow up in three years after surgery. Sixty-seven patients (77 hips) were included in this study. Results The pre-operative Harris hip scores and pain scores were 45 and 15 points. They increased to 89 and 42 points by the third year. These scores decreased to 81 and 42 points in the ninth year and 77 and 37 points in the fifteenth year, respectively. More than 75% of the hips demonstrated good or excellent clinical results in the fifth year and 60% of the hips were rated good to excellent in the seventh to eleventh year. In the fifteenth year, only 50% of the hips had good or excellent results. All femoral components showed stable fixation by bone in-growth. Eight acetabular components were revised, with 5 due to mechanical loosening and 3 for recurrent instability. Thigh pain was documented in 4 hips. ConclusionThe smooth-surfaced threaded acetabular component has a high rate of failure. Circumferential proximal porous coated femoral components provided excellent radiographic results and acceptable clinical outcome with definite bone ingrowth. Patients older than 70 may be suitable candidates for cementless total hip arthroplasty.

Anterior muscle sparing approach for total hip arthroplasty

The purpose of this review is to examine the validity of positive claims regarding the direct anterior approach(DAA) with a fracture table for total hip arthroplasty. Recent literature regarding the DAA was searched and specific claims investigated including improved early outcomes, speed of recovery, component placement, dislocation rates, and complication rates. Recent literature is positive regarding the effects of total hip arthroplasty with the anterior approach. While the data is not definitive at present, patients receiving the anterior approach for total hip arthroplasty tend to recover more quickly and have improved early outcomes. Component placement with the anterior approach is more often in the "safe zone" than with other approaches. Dislocation rates tend to be less than 1% with the anterior approach. Complication rates vary widely in the published literature. A possible explanation is that the varianceis due to surgeon and institutional experience with the anterior approach procedure. Concerns remain regarding the "learning curve" for both surgeons and institutions. In conclusion, it is not a matter of should this approach be used, but how should it be implemented.

Direct anterior total hip arthroplasty: Literature review of variations in surgical technique

The direct anterior approach to the hip has been suggested to have several advantages compared to previously popular approaches through its use of an intra-muscular and intra-nervous interval betweenthe tensor fasciae latae and sartorius muscles. Recent increased interest in tissue-sparing and minimallyinvasive arthroplasty has given rise to a sharp increase in the utilization of direct anterior total hip arthroplasty. A number of variations of the procedure have been described and several authors have published their experiences and feedback to successfully accomplishing this procedure. Additionally, improved understanding of relevant soft tissue constraints and anatomic variants has provided improved margin of safety for patients. The procedure may be performed using speciallydesigned instruments and a fracture table, however many authors have also described equally efficacious performance using a regular table and standard arthroplasty tools. The capacity to utilize fluoroscopy intraoperatively for component positioning is a valuable asset to the approach and can be of particular benefit for surgeons gaining familiarity. Proper management of patient and limb positioning are vital to reducing risk of intra-operative complications. An understanding of its limitations and challenges are also critical to safe employment. This review summarizes the key features of the direct anterior approach for total hip arthroplasty as an aid to improving the understanding of this important and effective method for modern hip replacement surgeons.

Total hip arthroplasty in developmental dysplasia of the hip: Review of anatomy, techniques and outcomes

Total hip arthroplasty(THA) in developmental dysplasia of the hip(DDH) presents many challenges to the reconstructive surgeon. The complex femoral and acetabular anatomy makes standard reconstruction technically challenging. Acetabular coverage can be improved by medialization of the component or augmentation of the deficient areas with bone graft. Femoral shortening osteotomies are considered in cases of severe dysplasia and frankly dislocated hips. Each patient's unique anatomy dictates what options of reconstruction are available. The functional outcomes of THA in DDH are generally excellent, though higher rates of mechanical failure have been reported in this group. This article reviews the anatomy, classification, technical considerations, and outcomes of THA in patients with DDH.

Direct anterior total hip arthroplasty:Comparative outcomes and contemporary results

Direct anterior total hip arthroplasty has become increasingly more popular among arthroplasty surgeons,in large part due to the use of an intramuscular interval and desire to reduce soft tissue damage.Several studies have now been published comparing the anterior intramuscular to other commonly used approaches,and many studies have published complication rates on large series of patients.Review of comparative studies indicates direct anterior hips tend towards shorter hospital stays and high rates of patients discharged to home.Although some studies show evidence of early benefit in functional outcomes,there is no strong evidence that the anterior approach provides any long term functional improvements compared to other approaches.Additionally,evidence to support reduced damage to soft tissue may not translate to certain clinical significance.Rates of intra-operative femur fracture,operative time and blood loss rates are notably higher for those developing familiarity with this approach.However,when surgeons have performed a modest number of procedures,the complication rates tend to markedly decrease in most studies to levels comparable to other approaches.Accuracy of component positioning also favors the anterior approach in some studies.This review summarizes the available literature comparing the direct anterior to other approaches for total hip arthroplasty and provides a comprehensive summary of common complications.

Instability after total hip arthroplasty

Instability following total hip arthroplasty(THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Non-operative management is often successful if the components are well-fixed and correctly positioned in the absence of neurocognitive disorders. If conservative management fails, surgical options include revision of malpositioned components; exchange of modular components such as the femoral head and acetabular liner; bipolar arthroplasty; tripolar arthroplasty; use of a larger femoral head; use of a constrained liner; soft tissue reinforcement and advancement of the greater trochanter.

Dual mobility cups in total hip arthroplasty

Total hip arthroplasty(THA)is considered one of the most successful surgical procedures in orthopaedics.With the increase in the number of THAs performed in the world in the next decades,reducing or preventing medical and mechanical complications such as post-operative THA instability will be of paramount importance,particularly in an emerging health care environment based on quality control and patient outcome.Dual mobility acetabular component(also known as unconstrained tripolar implant)was introduced in France at the end of the 1970s as an alternative to standard sockets,to reduce the risk of THA dislocation in patients undergoing primary THA in France.Dual mobility cups have recently gained wider attention in the United States as an alternative option in the prevention and treatment of instability in both primary and revision THA and offer the benefit of increased stability without compromising clinical outcomes and implant longevity.In this article,we review the use of dual mobility cup in total hip arthroplasty in terms of its history,biomechanics,outcomes and complications based on more than20 years of medical literature.

Digital templating in total hip arthroplasty:Additional anteroposterior hip view increases the accuracy

AIM To analyze planning total hip arthroplasty(THA) with an additional anteroposterior hip view may increases the accuracy of preoperative planning in THA.METHODS We conducted prospective digital planning in 100 consecutive patients: 50 of these procedures were planned using pelvic overview only(first group), and the other 50 procedures were planned using pelvic overview plus antero-posterior(a.p.) hip view(second group). The planning and the procedure of each patient were performed exclusively by the senior surgeon. Fifty procedures with retrospective analogues planning were used as the control group(group zero). After the procedure, the planning was compared with the eventually implanted components(cup and stem). For statistic analysis the x^2 test was used for nominal variables and the t test was used for a comparison of continuous variables.RESULTS Preoperative planning with an additional a.p. hip view(second group) significantly increased the exact component correlation when compared to pelvic overview only(first group) for both the acetabular cup and the femoral stem(76% cup and 66% stem vs 54% cup and 32% stem). When considering planning ± 1 size, the accuracy in the second group was 96%(48 of 50 patients) for the cup and 94% for the stem(47 of 50patients). In the analogue control group(group zero), an exact correlation was observed in only 1/3 of the cases.CONCLUSION Digital THA planning performed by the operating surgeon and based on additional a.p. hip view significantly increases the correlation between preoperative planning and eventual implant sizes.