Is Robotic Arm Assisted Total Hip Arthroplasty More Bone Preserving than Conventional Hip Replacements and Hip Resurfacing?

Background: Total hip arthroplasty (THA) is a common procedure that is increasingly being performed in younger patients. Deep acetabular reaming will result in more bone loss and the need for large acetabular components to be implanted. It can also lead to impingement, loosening, an altered center of rotation, and intraoperative periprosthetic fracture. The purpose of this study is to determine whether the single ream, robotic arm-assisted (RAA) THA can preserve a greater volume of bone stock compared to conventional hip replacement and resurfacing. Methods: We prospectively recruited 69 patients who had undergone primary THA using the Stryker Trident Acetabular System®in combination with the Stryker RAA System (MAKO)®and compared their mean reaming weight (g) with that of conventional hip replacement and resurfacing, as measured by Brennan et al. Comparison of acetabular reaming during hip resurfacing versus uncemented THA (J Orthop Surg. 2009;17(1): 42-46). Results: The mean reaming weight using the MAKO system was 9.08 g, which was 29% less than the reaming weight using uncemented THA and hip resurfacing of 12.75 g. None of the acetabular cups required screw fixation. During the 35-month follow-up period, there were no complications related to cup placement or positioning. Conclusions: The use of RAA THA results in statistically significant preservation of acetabular bone compared to conventional hip replacement and resurfacing. This approach reflects the increased precision offered by RAA single reaming. Surgeons may consider utilizing RAA THA, particularly in younger patients, to better preserve bone stock as this could potentially impact future revision procedures.

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.

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.

Examining the“revisability”benefit of hip resurfacing arthroplasty

BACKGROUND Hip resurfacing arthroplasty(HRA)is an alternative to total hip arthroplasty(THA)that is typically reserved for young active patients because it preserves bone.However,the benefits of HRA only hold true if conversion THA after failed HRA provides acceptable outcomes.AIM To compare patient reported outcomes for conversion THA after HRA failure to primary THA.METHODS A retrospective review of 36 patients(37 hips)that underwent conversion THA for failed HRA between October 2006 and May 2019 by a single surgeon was performed.Patient reported outcomes[modified Harris Hip Score(mHHS),University of California Los Angeles(UCLA)activity score]were obtained via an email-based responder-anonymous survey.Outcomes were compared to normative data of a primary THA cohort with similar demographics.Subgroup analysis was performed comparing outcomes of conversion THA for adverse local tissue reaction(ALTR)vs all other causes for failure.RESULTS The study group had a lower mHHS than the control group(81.7±13.8 vs 90.2±11.6,P<0.01);however,both groups had similar UCLA activity levels(7.5±2.3 vs 7.2±1.6,P=0.51).Patients that underwent conversion for non-ATLR causes had similar mHHS(85.2±11.5 vs 90.2±11.6,P=0.11)and higher UCLA activity levels(8.5±1.8 vs 7.2±1.6,P<0.01)compared to the control group.Patients that underwent conversion for ATLR had worse mHHS(77.1±14.5 vs 90.2±11.6,P<0.01)and UCLA activity levels(6.1±2.3 vs 7.2±1.6,P=0.05)when compared to the control group.CONCLUSION Patient outcomes equivalent to primary THA can be achieved following HRA conversion to THA.However,inferior outcomes were demonstrated for ALTR-related HRA failure.Patient selection and perhaps further studies examining alternative HRA bearing surfaces should be considered.

Comparison of femoral neck fracture healing and affected limb pain after anterolateral-approach minimally invasive total hip replacement and hemiarthroplasty

Objective:To study the differences in femoral neck fracture healing and affected limb pain after anterolateral-approach minimally invasive total hip replacement and hemiarthroplasty. Methods:A total of 92 patients with femoral neck fracture who received hip replacement in our hospital between May 2013 and December 2015 were selected and randomly divided into total hip and half hip group, total hip group received anterolateral-approach minimally invasive total hip replacement, half hip group received anterolateral-approach minimally invasive hemiarthroplasty, and 1 month after operation, serum was collected to detect the levels of bone metabolism markers, osteocyte cytokines, SP and CGRP.Results:1 month after operation, serum PINP, PICP, BMP, TGF-β, FGF, IGF-I and IGF-II levels of total hip group were significantly higher than those of half hip group while TRAP5b and CatK levels were significantly lower than those of half hip group;the day after operation, serum pain media SP and CGRP levels were not significantly different between the two groups of patients;36 h after operation, serum SP and CGRP levels of total hip group were significantly lower than those of half hip group.Conclusion:The bone metabolism after anterolateral-approach minimally invasive total hip replacement is better than that after hemiarthroplasty, and the degree of pain is less than that after hemiarthroplasty.

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.

Osteolysis in total hip arthroplasty in relation to metal ion release: Comparison between monolithic prostheses and different modularities

BACKGROUND Among the various complications associated with total hip arthroplasty(THA)periprosthetic osteolysis and wear phenomena due to the release of metal particles,are two of the most common and have been reported to be correlated because of inflammatory responses directed towards released particles that generally activate macrophagic osteolytic effects.Therein,new masses known as pseudotumors can appear in soft tissues around a prosthetic implant.To date,there is paucity of reliable data from studies investigating for any association between the above mentioned adverse events.AIM To investigate for the existence of any association between serum and urine concentrations of metal-ions released in THA and periprosthetic osteolysis for modular neck and monolithic implants.METHODS Overall,76 patients were divided into three groups according to the type of hip prosthesis implants:Monoblock,modular with metal head and modular with ceramic head.With an average f-up of 4 years,we conducted a radiological evaluation in order to detect any area of osteolysis around the prosthesis of both the femur and the acetabulum.Moreover,serum and urinary tests were performed to assess the values of Chromium and Cobalt released.Statistical analysis was performed to determine any association between the ion release and osteolysis.RESULTS For the 3 study groups,the monolithic,modular ceramic-headed and modular metal-headed implants had different incidences of osteolysis events,which were higher for the modular implants.Furthermore,the most serious of these(grade 3)were detected almost exclusively for the modular implants with metal heads.A mapping of the affected areas was performed revealing that the highest incidences of osteolysis were evidenced in the pertrochanteric region at the femur level,and in the supero-external region at the acetabular level.Regarding the evaluation of the release of metals-ions from wear processes,serum and urinary chromium and cobalt values were found to be higher in cases of modularity,and even more so for those with metal head.Statistical linear correlation test results suggested positive correlations between increasing metal concentrations and incidences areas of osteolysis.However,no cases of pseudo-tumor were detected.CONCLUSION Future studies are needed to identify risk factors that increase peri-prosthetic metal ion levels and whether these factors might be implicated in the triggering of local events,including osteolysis and aseptic loosening.

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.

Conversion hip arthroplasty for failed nailing of intertrochanteric fracture: Reflections on some important aspects

In this editorial,I present my comments on the article by Solarino et al.Conversion hip arthroplasty,which is an optional salvage procedure performed following unsuccessful fixation of intertrochanteric femur fractures in elderly pati-ents,entails more complex processes and higher rates of operative complications than primary arthroplasty.Hence,it is important to consider the appropriateness of the primary treatment choice,as well as the adequacy of nailing fixation for intertrochanteric fractures.This article briefly analyzes the possible factors contributing to the nailing failure of intertrochanteric fractures and attempts to find corresponding countermeasures to prevent fixation failures.It also analyzes the choice of treatment between nailing fixation and primary arthroplasty for intertrochanteric fractures.

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.

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.

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.

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.

Intermediate Hip Arthroplasty in Gabon: Blood Loss and Risk Factor for Transfusion

Background: Hip arthroplasty is a surgery with a high risk of bleeding. The main objective of this study was to research risk factors for bleeding and transfusion in patients undergoing hip hemiarthroplasty in Gabon. Method: It was a retrospective, monocentric, descriptive and analytical study carried out from June 2011 to June 2021 at the Omar Bongo Ondimba army training hospital. The variables studied were demographic characteristics, biological variables, transfusion and intraoperative data. The primary outcome was intraoperative transfusion. A univariate and multivariate analysis was conducted to identify the factors associated with the occurrence of a transfusion. Results: Of the 97 patients included, the average age was 74.2 years ± 10, male predominance was 73.2%, the average ASA score was 1.9 ± 0.5, and transfusion incidence was 38.1%. The average number of RBCs transfused was 1.2 ± 0.6. Tranexamic acid was used in 11.3% of patients. The average bleeding was 450 ± 453 ml. Preoperative anemia was predictor of transfusion to be significant. Conclusion: The incidence of transfusion is law compared to total hip arthroplasty. The implementation of a patient blood management protocol is difficult given the urgency of bone repair. However, a better use of tranexamic acid could reduce this transfusion incidence.

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.

Assessment of the effectiveness of weight-adjusted antibiotic administration,for reduced duration,in surgical prophylaxis of primary hip and knee arthroplasty

BACKGROUND Prophylactic antibiotics have significantly led to a reduction in the risk of postoperative surgical site infections(SSI)in orthopaedic surgery.The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed,for the duration of the operation,the minimum inhibitory concentration of the likely organisms that are encountered.Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4%and 8%to between 1%and 3%.Controversy,however,still surrounds the optimal frequency and dosing of antibiotic administration.AIM To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime,combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty METHODS Following ethical approval,patients undergoing primary total hip arthroplasty(THA)/total knee arthroplasty(TKA)with the old regime(OR)of a preoperative dose[cefazolin 2 g intravenously(IV)],and two subsequent doses(2 h and 8 h),were compared to those after a change to a new regime(NR)of a weight-adjusted preoperative dose(cefazolin 2 g IV for patients<120 kg;cefazolin 3g IV for patients>120 kg)and a post-operative dose at 2 h.The primary outcome in both groups was SSI rates during the 2 years post-operatively.RESULTS A total of n=1273 operations(THA n=534,TKA n=739)were performed in n=1264 patients.There was no statistically significant difference in the rate of deep(OR 0.74%(5/675)vs NR 0.50%(3/598);fishers exact test P=0.72),nor superficial SSIs(OR 2.07%(14/675)vs NR 1.50%(9/598);chi-squared test P=0.44)at 2 years postoperatively.With propensity score weighting and an interrupted time series analysis,there was also no difference in SSI rates between both groups[RR 0.88(95%CI 0.61 to 1.30)P=0.46].CONCLUSION A weight-adjusted regime,with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Total hip arthroplasty following the failure of intertrochanteric nailing:First implant or salvage surgery?

BACKGROUND Proximal femur fractures,including both intracapsular(femoral neck fractures)and extracapsular fractures(intertrochanteric femoral fractures,IFFs),affect around 1.5 million people per year worldwide.Mechanical failures of intertrochanteric nailing in IFFs could be managed with revision total hip arthroplasty(THA).AIM To describe the surgical complexity and the procedure-related complication rates in patients with trochanteric nailing failure and treated with THA.METHODS Patients referred to our level I trauma center between April 2012 and July 2018 with failed cephalomedullary nailing following trochanteric fractures were retrospectively recruited.All patients underwent a salvage surgical procedure,i.e.,cephalomedullary nail removal and conversion to THA.The same surgical and anesthesiology team performed the surgical procedures under spinal anesthesia.All patients underwent clinical and radiographic follow-ups for at least 24 mo.Complications and re-operations were recorded.RESULTS Seventy-four patients met the inclusion criteria(male:29;female:45;mean age:73.8-years-old;range:65-89)and were included in the current study.The average operative time was 117 min(76-192 min).The average blood loss was 585 mL(430-1720 mL).Among the 74 patients,43(58.1%)required transfusion of three or more blood units.Two patients died within the 4th d after surgery because of pulmonary embolism,and 1 patient died 9 mo after surgery due to ischemic myocardial infarction.The complication rate in the 71 patients who completed the minimum 24-mo follow-up was 22.5%.In 3 cases out of 71(4.2%)periprosthetic acetabular fracture was observed during the followup.One of these periacetabular fractures occurred intraoperatively.An intraoperative periprosthetic femur fracture was observed in 5 patients out of 71(7.0%).Four of these patients needed a re-operation to fix the fracture with plates and cerclages;in one of these patients,femoral stem revision was also necessary.In 4 patients out of 71(5.6%),an early THA dislocation was observed,whereas in 1 case(1.4%)a late THA dislocation was observed.Three patients out of 71(4.2%)developed a periprosthetic joint infection during the study follow-up.CONCLUSION The present study demonstrated that salvage options for IFF fixation failure are complex procedures with a relevant intraoperative and postoperative complication rate.

Acetabular cup size trends in total hip arthroplasty

BACKGROUND Total hip arthroplasty(THA)is a common procedure for end stage osteoarthritis.The learning curve for THA is complex and challenging.One of the most difficult skills to master is acetabular reaming.We wish to identify if experience in arthroplasty leads to preservation of more bone stock.AIM To investigate if increasing surgeon experience will predict an ever decreasing acetabular cup size.METHODS A retrospective case series of four attending orthopaedic surgeons was completed.All uncemented elective total hip arthroplasties since appointment were selected for inclusion.The size of acetabular cup used was noted and logistic regression was used to identify if a trend to smaller cups existed.RESULTS A total of 1614 subjects were included with a mean age of 64 years.Overall cups were on average 0.18mm smaller per year(95%confidence interval-0.25 to-0.11,P<0.001).Individual surgeon trends showed cup sizes to decrease 0.27 mm/year for surgeon A,0.02 mm/year for surgeon B,0.15 mm/year for surgeon C and 0.29 mm/year for surgeon D.Three of the four surgeons had a more pronounced trend to smaller cups for male subjects than their female counterparts.CONCLUSION We found increasing surgeon experience to be associated with an ever-decreasing acetabular cup size.Smaller acetabular cup size may act as a surrogate marker of surgical proficiency by virtue of decreased acetabular reaming.

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.

Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures

BACKGROUND Hip fractures account for 23.8%of all fractures in patients over the age of 75 years.More than half of these patients are older than 80 years.Bipolar hemiarthroplasty(BHA)was established as an effective management option for these patients.Various approaches can be used for the BHA procedure.However,there is a high risk of postoperative dislocation.The conjoined tendon-preserving posterior(CPP)lateral approach was introduced to reduce postoperative dislocation rates.AIM To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients.METHODS We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA.The patients were followed up for at least 1 year.Among the 80 patients,57(71.3%)were female.The time to operation averaged 2.3 d(range:1-5 d).The mean age was 80.5 years(range:67-90 years),and the mean body mass index was 24.9 kg/m^(2)(range:17-36 kg/m^(2)).According to the Garden classification,42.5%of patients were typeⅢand 57.5%of patients were typeⅣ.Uncemented bipolar hip prostheses were used for all patients.Torn conjoined tendons,dislocations,and adverse complications during and after surgery were recorded.RESULTS The mean postoperative follow-up time was 15.3 months(range:12-18 months).The average surgery time was 52 min(range:40-70 min)with an average blood loss of 120 mL(range:80-320 mL).The transfusion rate was 10%(8 of 80 patients).The gemellus inferior was torn in 4 patients(5%),while it was difficult to identify in 2 patients(2.5%)during surgery.The posterior capsule was punctured by the fractured femoral neck in 3 patients,but the conjoined tendon and the piriformis tendon remained intact.No patients had stem varus greater than 3 degrees or femoral fracture.There were no patients with stem subsidence more than 5 mm at the last follow-up.No postoperative dislocations were observed throughout the follow-up period.No significance was found between preoperative and postoperative mean Health Service System scores(87.30±2.98 vs 86.10±6.10,t=1.89,P=0.063).CONCLUSION The CPP lateral approach can effectively reduce the incidence of postoperative dislocation without increasing perioperative complications.For surgeons familiar with the posterior lateral approach,there is no need for additional surgical instruments,and it does not increase surgical difficulty.