The relative advantages and disadvantages of two-stage versus one-stage management of infected total hip arthroplasties are the current subject of intense debate. To understand the merits of each approach detailed information on the short and, importantly, longer-term outcomes of each must be known. The purpose of this study was to assess the long-term results of two-stage exchange arthroplasty for THAs in one of the largest series to date.

We identified 331 infected THAs treated with a two-stage exchange arthroplasty between 1993 and 2021 at a single institution. Patients were excluded if they had prior treatment for infection. Mean age at reimplantation was 66 years, 38% were female, and mean BMI was 30 kg/m². PJI diagnosis was based on the 2011 MSIS criteria. A competing risk model accounting for death was utilized. Mean follow up was 8 years.

The cumulative incidence of reinfection was 7% at 1 year and 11% at 5 and 10 years. Factors predictive of reinfection included BMI>30 kg/m² (HR 2; p=0.049), and need for a spacer exchange (HR 3.2; p=0.006). The cumulative incidence of any revision was 13% at 5 and 10 years. The cumulative incidence of aseptic revision was 3% at 1 year, 7% at 5 years, and 8% at 10 years. Dislocation occurred in 33 hips (11% at 10 years; 45% required revision). Factors predictive of dislocation were female sex (HR 2; p=0.047) and BMI<30 kg/m² (HR 3; p=0.02). The mean HHS improved from 54 to 75 at 10 years.

In this series of 331 two-stage exchange arthroplasties performed for infected hips, we found a low aseptic revision rate (8%) and a low rate of reinfection (11%) at 10 years. These long-term mechanical and infection data must be kept in mind when considering a paradigm shift to one-stage exchanges.

Level of Evidence: Level III

Studies and meta-analyses worldwide show an increased use of one-stage revisions for treating periprosthetic hip infections, often yielding comparable or better outcomes than two-stage revisions. However, it remains unclear if these successful results can be consistently achieved nationwide besides large centers.

This observational cohort study used data from the German Arthroplasty Registry (EPRD) to compare the mortality and re-revision rates between one-stage (n=8183) and two-stage (n=657) first-time revision total hip arthroplasty (RTHA). Kaplan-Meier estimates were applied to evaluate the re-revision rate and cumulative mortality for RTHA.

There was a significant difference in mortality between one-stage and two-stage RTHA (p=0.02). One-year post-surgery, the mortality rate was 9.4% for one-stage revisions and 5.5% for two-stage revisions. At the five-year follow-up, the mortality rate for one-stage revisions was 25.5%, compared to 20.0% for two-stage revisions. No significant differences (p=0.30) were found in re-revision rates between one-stage and two-stage revisions after one year (one-stage 16.5% vs. two-stage 13.5%) or five years (one-stage 21.6% vs. two-stage 20.8%). For multiple revisions, the mortality differences were even larger (p<0.001), with a one-year mortality rate of 12.8% for one-stage RTHA and 5.7% for two-stage RTHA.

Despite the excellent results of one-stage RTHA in the literature from individual large centers, it shows a significantly higher mortality rate with equal re-revision rate compared to two-stage revision in the nationwide care besides large centers. Significant differences can already be seen within the first year, indicating an increased perioperative mortality for one-stage revision, which might be explained by longer surgery duration, blood-loss and patient selection or maybe a lack of experience concerning proper surgical debridement for one-stage revision. This illustrates the need to establish centers for joint-revision surgery that provide interdisciplinary care and high case numbers to improve perioperative outcomes.

We compared the risks of re-revision and mortality between two-stage and single-stage revision surgeries among patients with infected primary hip arthroplasty. Patients with a periprosthetic joint infection (PJI) of their primary arthroplasty revised with single-stage or two-stage procedure in England and Wales between 2003 and 2014 were identified from the National Joint Registry. We used Poisson regression with restricted cubic splines to compute hazard ratios (HRs) at different postoperative periods. The total number of revisions and re-revisions undergone by patients was compared between the two strategies. In total, 535 primary hip arthroplasties were revised with single-stage procedure (1,525 person-years) and 1,605 with two-stage procedure (5,885 person-years). All-cause re-revision was higher following single-stage revision, especially in the first three months (HR at 3 months = 1.98 (95% confidence interval (CI) 1.14 to 3.43), p = 0.009). The risks were comparable thereafter. Re-revision for PJI was higher in the first three postoperative months for single-stage revision and waned with time (HR at 3 months = 1.81 (95% CI 1.22 to 2.68), p = 0.003; HR at 6 months = 1.25 (95% CI 0.71 to 2.21), p = 0.441; HR at 12 months = 0.94 (95% CI 0.54 to 1.63), p = 0.819). Patients initially managed with a single-stage revision received fewer revision operations (mean 1.3 (SD 0.7) vs 2.2 (SD 0.6), p < 0.001). Mortality rates were comparable between these two procedures (29/10,000 person-years vs 33/10,000). The risk of unplanned re-revision was lower following two-stage revision, but only in the early postoperative period. The lower overall number of revision procedures associated with a single-stage revision strategy and the equivalent mortality rates to two-stage revision are reassuring. With appropriate counselling, single-stage revision is a viable option for the treatment of hip PJI.

Two-stage exchange arthroplasty is traditionally used to treat periprosthetic hip infection. Nevertheless, particularly in high-risk patients, there has been increased attention towards alternatives such as 1.5-stage exchange arthroplasty which takes place in one surgery. Therefore, we sought to compare (1) operative time, length-of-stay (LOS), transfusions, (2) causative organism identification and polymicrobial infection rates, (3) re-revision rates and re-revision reasons, (4) mortality, and determine (5) independent predictors of re-revision.

Retrospective chart review of 71 patients who underwent either 1.5- (n=38) or 2-stage (n=33) exchange hip arthroplasty at a single institution (03/2019-05/2023). Demographics, surgical, inpatient, and infection characteristics were noted. Main outcomes evaluated were re-revision rates, re-revision reasons, mortality, and cause of death. Independent predictors of re-revision were assessed utilizing logistic regression. Mean follow: 675 days (range, 23–1,715).

Demographics were not significantly different except for a higher proportion of 1.5-stage patients classified as American-Society-of-Anesthesiologists (ASA) status 3 or 4 (84.2 vs. 48.5%, p=0.002). Length of follow-up was significantly longer in the 2-stage group (924.4 vs. 458 days, p<0.001) as well as operative time (506 vs. 271 minutes, p<0.001). In the 1.5-stage group, there was a higher proportion of polymicrobial infections (23.7 vs. 3.0%, p=0.016), re-revision rates (28.9 vs. 9.1%, p=0.042) and periprosthetic infections as a cause of revision (90.9 vs. 0%, p=0.007). Mortality rates were not significantly different, and no patient died for causes related to infection. Type of surgery (1.5-stage vs. 2-stage) was the only independent predictor of re-revision (odds-ratio 4.0, 95% confidence-interval 1.02–16.16, p=0.046).

Our data suggests that patients who undergo 1.5-stage exchange arthroplasty have a significantly higher re-revision rate (mostly due to infection) when compared to 2-stage patients. We acknowledge potential benefits of the 1.5-stage strategy, especially in high-risk patients since it involves single surgery. However, higher re-revision rates must be considered when counseling patients.

High doses of intra-articular (IA) antibiotics has been shown to effectively achieve a minimal biofilm eradication concentration which could mitigate the need for removal of infected but well-ingrown cementless components of a total hip arthroplasty (THA). However, there are concerns that percutaneous catheters could lead to multi-resistance or multi-organism peri-prosthetic joint infections (PJI) following single stage THA revisions for PJI.

Eighteen single-stage revision procedures were performed for acute (N=9) or chronic (N=9) PJI following a primary (N=12) or revision (N=6) cementless THA. Modular and loosened components were replaced. All well ingrown components were retained. Two Hickmann catheters were placed in the joint space. Along with intravenous antibiotics, IA antibiotics were injected twice a day for two weeks, followed by 3 months of oral antibiotics.

Per-operative cultures demonstrated 4 multi-bacterial PJIs. None of the patients developed post-operatively an AB related renal or systemic dysfunction. At a mean follow-up of 38 months [range, 8–72] all patients had normal erythrocyte sedimentation rate and white blood cell count. Four had a slightly elevated C-reactive protein but were completely symptom free and did not show any sign of loosening at a mean of 27 months [range, 16–59].

Addition of high doses of IA antibiotics following single-stage revision for PJI in cementless THA, is an effective and safe treatment option that allows for retention of well-ingrown components. We found no evidence for residual implant infection or catheter induced multi-resistance.

Total hip arthroplasty, revision surgery, Periprosthetic Joint Infection, Intra-articular antibiotics

Level 4 (Case series)

Mechanical failure due to dislocation, fracture and acetabular wear as well as persistence of infection are the main complications associated with the use of hip spacers in the treatment of periprosthetic joint infections (PJI).

We have developed a novel, custom-made spacer as part of two-stage septic hip replacement and present the two- to five-year results after reimplantation.

We prospectively examined a total of 73 patients over our study period in whom our new spacer technique was used. The technique includes a dual mobility inlay and a cemented straight stem in combination with antibiotic-loaded PMMA bone cement which allows full weight bearing meanwhile the interim period. The follow-up ranged between 24 and 60 months after reimplantation as second stage of a two-stage approach. The patients were contacted as part of the follow-up using a questionnaire concerning reoperation, reinfection as well as hip function by using the Harris Hip Score.

72 patients (98,6%) could be reimplanted, one patient is still using the spacer prothesis for 45 months because of excellent functional results with a Harris Hip Score of 95, nevertheless reimplantation is planned. The reinfection rate was less than 7% after reimplantation. The dislocation rate was 5%, and in total there was an overall complication rate of less than 10%. The Harris Hip Score was significantly improved.

The ENDO spacer surgical technique is a promising option in the treatment of periprosthetic joint infections (PJI) for two-stage septic exchange with a low dislocation rate and good infection control after reimplantation. In addition, it enables early mobilization with the possibility of full weight-bearing in the interval between spacer implantation and reimplantation.

Traditional mechanical debridement can only remove visibly infected tissue and is unable to completely clear all the biofilm that hides within muscle crevices and nerves. This study aims to determine the results of single-stage revision using noncontact low frequency ultrasonic debridement in treating chronic periprosthetic joint infections (PJI).

A prospective study of consecutive patients requiring single-stage revision for chronic PJI was performed since August 2021. After mechanical debridement, an 8‑mm handheld non‑contact low‑frequency ultrasound probe was used for ultrasonic debridement at a frequency of (25±5) kHz and power of 90% for 5 minutes. Each ultrasound lasted 10 seconds with 3‑seconds intervals. The probe was repeatedly sonicated among all soft tissue and bsingle interface. The distal femoral canal and the posterior capsule of the knee were fully sonicated with a special right‑angle probe. Chemical debridement was then performed to irrigation the whole operative area. Recurrence of infection, culture results and number of colonies 24 hours after ultrasonic debridement were recorded.

A total of 45 patients (25 hips and 20 knees) were included and 43 of them (95.6%) were free of infection at a mean follow-up time of 29 months (24 to 33). There were no intraoperative complications related to ultrasonic debridement (neurovascular and muscle injury, poor wound healing and fat liquefaction). The culture‑positive rate of wound liquid before ultrasonic debridement was 40.0% (18/45), which significantly increased to 75.6% (34/45) after ultrasonic debridement (P=0.001). The median number of colonies 24 hours after ultrasonic debridement was 2372 CFU/ml (310 to 4340 CFU/ml), which was significantly higher than that before debridement (307 CFU/ml; 10 to 980 CFU/ml) (P=0.000).

Single-stage revision with non‑contact low‑frequency ultrasonic debridement can fully expose bacteria within biofilm, increase the efficacy of chemical debridement and lead to a favorable short‑term outcome without related complications.

In 2022, approximately 60% of inserted cups and stems in Sweden utilized cemented fixation. Two predominant brands, Refobacin Bone Cement R and Palacos R+G, both incorporating gentamicin, were employed in over 90% of primary cemented Total Hip Arthroplasties (THAs) between 2012 and 2022. This study investigates whether the choice between these cement types affects the risk of revision.

The five most frequently used cemented cups and the three most common stems were studied. Inclusion criteria encompassed hips with non-tumour diagnoses, operated through a direct lateral or posterior incision, featuring a 28–36 mm metal or ceramic head. Outcomes were assessed for cup revisions (n=55,457 Refobacin, 37,210 Palacos), stem revisions (n=51,732 Refobacin, 30,018 Palacos), and all-cemented THAs with either brand (n=45,265 Refobacin, 26,347 Palacos). Kaplan-Meier life tables and hazard ratios (HR) utilizing Cox regression were computed, adjusting for age, sex, diagnosis, implant type, femoral head size, and material.

Over a 10-year period, the cumulative percent revision with Refobacin was consistently higher than Palacos in all three analyses (cups: Refobacin 2.4 (2.3–2.5), Palacos 2.1 (2.0–2.2); stems: Refobacin 2.6 (2.5–2.7), Palacos 2.1 (2,0–2,2); all-cemented: Refobacin 3.2 (2.9–3.5), Palacos 2.9 (2.6–3.2)). Both unadjusted and adjusted HR were 13–25% lower with Palacos. In the analysis of all-cemented THAs, the adjusted HR for Palacos was 0.85 (0.76–0.95). Separating revisions into infectious and non-infectious reasons revealed a lower risk of infectious revisions with Palacos in all three analyses (all-cemented: adjusted HR infection 0.66 (0.56–0.78); non-infectious 1.10 (0.94–1.28)).

Hips cemented with Refobacin may face an increased risk of infection, potentially due to a smaller release of antibiotics into surrounding tissues. Unaccounted factors like different mixing systems or unknown biases could also influence outcomes, emphasizing the need for further investigation.

This meta analysis address the relationship between infection developing after total hip arthroplasty (THA) and heterotopic ossification (HO). To identify the gaps in available knowledge, we screened for full-length peer-reviewed research articles listed in PubMed, Embase, and Web of Science over the past 20 years. The following search terms and Boolean operators were used: heterotopic ossification AND infection AND (hip replacement OR hip arthroplasty). The search resulted in the identification of as few as 14 articles describing periprosthetic joint infection (PJI) and HO after THA. Data summarized from 6 studies suitable for further meta-analysis yielded a cumulative sample size of 753 observations, with 186 recorded events of HO. The pooled RR was estimated at 2.22 (95% CI: 1.00 to 4.91, p = 0.0497), suggesting a more than twofold risk of HO compared to the group without PJI. In conclusion, there is a clear association between a higher risk of HO and PJI. Basic research findings support the hypothesis that bacterial pathogen-associated molecular patterns (PAMPs) can lead to osteogenesis through a toll-like receptor (TLR) and nuclear factor kappa B (NF-κB) pathway in the course of HO development. Together, these results suggest that HO prophylaxis should always be prescribed in PJI after THA. Moreover, during revisions following THA for presumed non-septic reasons, the presence of HO warrants consideration for infection, as there is a potential heightened risk of pathologic ossification induced by PAMPs.

Keywords: heterotopic ossification; total hip arthroplasty; total hip replacement; periprosthetic joint infection; bacteria

Authors Ł. Pulik and P. Łęgosz contributed equally to this work.

Retained polymethylmethacrylate (PMMA) debris in surgical instrument trays is a rare, but disquieting situation for the arthroplasty surgeon. Although retained debris could be considered to be sterile after autoclaving, there is no peer-reviewed literature to support this assumption. This uncertainty and subsequent fear of contamination from this bioburden often leads to operating room personnel turning over entire surgical tables and opening new surgical instruments, which consumes time and burdens a hospital's sterilization infrastructure. Consequently, the purpose of the current study was to determine if retained, heavily contaminated PMMA in surgical trays could be effectively sterilized through clinically utilized autoclave protocols.

MSSA (Xen36, Perkin Elmer) biofilm was grown on identically sized PMMA (Palacos R) coupons for 72-hour duration. Following incubation, coupons were exposed to three commonly used sterilization protocols. Cobalt-Chrome (CC) coupons were included in the same tray, replicating instruments in proximity to retained PMMA. Autoclave protocols included: 1.) Single Instrument Flash protocol: Pre-vac, 270° F, 10 min exposure, 1 min drying, 2.) One Tray OR protocol: Pre-vac, 270° F, 4 min exposure, 1 min drying, and 3.) Standard Post-Operative protocol: Pre-vac, 270° F, 10 min exposure, 60 min drying. Control coupons did not undergo autoclaving. Coupons were then sonicated for 30 minutes in tryptic soy broth and plated to count CFUs. Experiments were performed in quadruplicate.

Control coupons showed significant contamination with CFU counts in the range of 10⁶ CFU/mL. CFU counts of zero across all autoclaved PMMA and CC coupons revealed that each protocol was effective in completely eradicating culturable S. aureus, confirming clinical efficacy on orthopaedic cement sterilized in surgical trays.

Our findings demonstrate that heavily contaminated PMMA and exposed metal in surgical trays can be effectively sterilized through several autoclaving protocols.

Clinicians should feel confident in the efficacy of autoclave protocols in removing bacteria and its associated biofilm from othopaedic materials.

We created TiO₂ nanotubes (TNTs) on the surface of titanium (Ti) implants with subsequential loading with gentamicin and chitosan, acting as a control release agent, by electrophoretic deposition (EPD). We hypothesized femoral implants with TNTs loaded with gentamicin and chitosan would localize antibiotic to the implant and surgical site and prevent PJI in a mouse model.

Ti-6Al-4V ELI wires underwent TNT surface modification by two-step anodization. EPD was then used to load gentamicin and chitosan onto the Ti wire with surface TNTs. Control Ti wires contained TNTs with EPD of chitosan only. 12-week-old male C57BL/6J mice underwent received a right femoral intramedullary implant followed by inoculation at the surgical site with 1×10³ CFUs of bioluminescent Xen36 Staphylococcus aureus (S. aureus). Mice were randomly divided into two implant groups: 1) Gentamicin + Chitosan Group (n=7; experimental group); 2) Chitosan Group (n=7; control group). Outcomes included: 1) Relative S. aureus abundance by bioluminescence imaging; 2) Quantification of S. aureus at the implant and surrounding tissue by colony forming unit (CFU) analysis; 3) Scanning electron microscopy (SEM) for implant bacterial biofilm; 4) Radiographic signs of PJI.

Over 14 days assessment following wire implantation and inoculation with S. aureus, the experimental group had no evidence of infection based on i) no increased Xen36 S. aureus bioluminescence signal and ii) no CFUs present. All control had increased bioluminescence signal, above baseline, at all time-points and presence of CFUs.

Ti femoral implants modified with surface TNTs and coated with gentamicin and chitosan through EPD prevented PJI in all mice through 14 days. In comparison, all control mice demonstrated evidence of PJI over 14 days. Implants with TNTs and EPD of gentamicin were highly effective in this mouse PJI model.

This study aimed to verify the hypothesis that an antibiotic loaded hydrogel, defensive antimicrobial coating (DAC), reduces overall complication and infection rates when used for high-risk primary and revision total hip arthroplasty (THA).

This was a retrospective study matched cohort study of 238 patients, treated with cementless implants with and without DAC. A sub-group analysis of patients undergoing 2nd stage revision THA for prosthetic joint infection (PJI) was also conducted. Re-infection rates within 2 years, complications necessitating surgical intervention and radiographic analysis for aseptic loosening was assessed.

The mean age was 68.3±11.5 years, with 39 (32.8%) Macpherson class A, 64 (53.8%) class B and 16 (13.4%) class C patients. 4 (3.4%) patients in the DAC group developed complications including 1 PJI and 1 delayed wound healing, while 13 (10.9%) patients in the control group developed complications including 5 PJIs and 3 delayed wound healing (p=0.032). PJI rates (p=0.136) and delayed wound healing rates (p=0.337) were not statistically significant. For 2nd stage revision THA for PJI there were 86 patients in the DAC group and 45 in the control group. 1 (1.2%) patient in the DAC group developed complications with no recurrences of infection or delayed wound healing, while 10 (22.2%) patients in the control group developed complications including 4 recurrent PJI and 1 delayed wound healing (p=0.003). Recurrent PJI rates were statistically significant (p=0.005) while delayed wound healing rates were not (p=0.165). Patients treated with DAC also had lower rates of aseptic loosening (0% vs 6.7%; p=0.015).

Antibiotic impregnated hydrogel coatings on cementless implants showed decreased complication rates after complex primary or revision THA. In 2nd stage revision THA for PJI, it was associated with reduced risk of re-infection and aseptic loosening.

The purpose of this randomized controlled trial was to evaluate serum metal levels in patients undergoing total hip arthroplasty (THA) with a conventional compared to a modular dual-mobility bearing.

Patients undergoing primary THA for osteoarthritis were randomized to receive either a modular dual-mobility or conventional polyethylene bearing. All patients received the same titanium acetabular and femoral component and a ceramic femoral head. Serum metal levels were drawn pre-operatively then annually for a minimum of two years postoperatively. An a priori power analysis determined that 40 patients (20 per cohort) were needed to identify a clinically relevant difference in serum cobalt of 0.35 ng/ml (ppb) at 90% power.

Forty-six patients were randomized to a modular dual-mobility (n=25) or conventional bearing (n=21) with 40 at a minimum follow-up of two years. No differences in serum cobalt (mean 0.14 ppb [range, 0.075–0.29] vs. 0.20 ppb [range, 0.075–0.57], p=0.39) or chromium levels (mean 0.14 ppb [range, 0.05–0.50] vs. 0.12 ppb [range, 0.05–0.35], p=0.65) were identified between the modular dual-mobility and conventional cohorts, respectively.

There was no statistically significant difference in serum Co or Cr at two years postoperatively in subjects implanted with a ceramic head and this particular dual mobility bearing in comparison to a ceramic head and a conventional acetabular component. While modest expected elevations in serum Co and Cr were observed in the dual mobility group, in no case did the Co level exceed the laboratory reference range nor the threshold of one part per billion that has been associated with adverse local tissue reactions to mechanically-assisted crevice corrosion.

Dislocation is still one of the more common reasons for revision of THR.Registry and large institutional data has demonstrated the effectiveness of Dual Mobility articulations in reducing revision for dislocation after THR. There is little data about whether the use of dual mobility is associated with a comprised clinical functional outcome.

This study aimed to ascertain whether the use of Dual Mobility articulations (DM cups) comes within a compromise to the functional of the THR procedure as measured by the Hip disability and Osteoarthritis Outcome Score (HOOS).

Utilising a retrospective design, patients were grouped into those with DM cups with 12 PROMs (Cohort 1) or a large data base of all THR procedures also with a complete set of 12 month PROMs (Cohort 2). The 2 groups were matched for age and gender through propensity score matching. The comparison focused on five domains of the HOOS: Pain, Symptoms, Activities of Daily Living (ADL), Sports and Recreation, and Quality of Life (QOL) at 6- and 12-months post-operation.

12 month PROM data suggested a convergence in scores for several domains, no uniform superiority of one articulation type over the other was found across all domains. These results suggest that both DM cup and standard articulations can effectively improve patient-reported outcomes in THR surgeries, but there are variations in recovery within each cohort that are potentially influenced by factors beyond the articulation type.

This study contributes to the ongoing dialogue on optimising prosthetic selection to enhance recovery trajectories and quality of life for THR patients, emphasising the critical role of evidence-based decision-making in orthopaedic surgery.

Dislocation after Total Hip Arthroplasty (THA) is a frequent cause of revision and patients with intrinsic risk factors have been identified. The use of dual mobility (DM) cup has shown great efficiency in preventing dislocation, with questions regarding selective or absolute use. The aim of this study was to compare the outcome of single mobility THA (SM-THA) and DM-THA, when used for selected patients.

This retrospective continuous cohort study evaluated 490 patients of whom 275 received SM-THA and 215 received DM-THA. There were 304 primary osteoarthritis (62%), 121 femoral neck fractures (24%) and 65 other indications (14%). The surgical approach was anterior (AA) in 79% and posterior (PA) in 21% of cases. In the DM-THA group, 189 patients (87%) presented at least one dislocation risk factor compared to 128 patients (46%) in the SM-THA group. The primary outcome was revision for all causes, with or without implant removal. Secondary outcomes included length of hospital stay.

There was no difference in all cause revision at two years follow up with 9 procedures (3.2%) in SM-THA group and 11 in DM-THA group (5.1%) (p=0.3). There were 3 dislocations in SM-THA group (3 AA) and 3 in DM-THA group (2 PA and 1 AA) (p=0.4).

The length of stay was significantly longer in DM-THA group with 7 days (2–12) compared to 4 days (1–7) in SM-THA group (p=0.001).

SM-THA and DM-THA are two complementary devices in the management of patients requiring primary THA. SM-THA is a safe option for patients without dislocation risk factors, especially when using AA. The identification of such factors is important to select patients requiring DM-THA and provide reproducible outcomes in a University Hospital practice including various levels of surgeon experience.

The benefits of total hip arthroplasty (THA) may be significantly magnified in children, since the improvement in quality of life has a far greater exposure time and occurs during key developmental stages which may help to maximise lifetime achievement. The purpose of this study is to describe implant survival and patient reported outcomes (PROMS) in a cohort of children following THA.

Retrospective cohort review of all patients treated with THA in a single centre. Routine data analysis did not require ethical approval.

Survival was estimated using Kaplan-Meier and PROMs were recorded (EQ5D-S, Oxford hip score and modified Harris Hip Score) in a sub-group of patients.

66 hips in 47 patients with a median age of 16 years (range 10 to 19 years) underwent THA between 1971 and 2023. 57% (38/68) patients were female, the commonest indications were Mucopolysaccharidoses n = 15, Stills disease (n=15), and Avascular necrosis (n=12). 27 (41%) of constructs were cemented, 5 (8%) were hybrid, and 34 (51%) were cementless. 30 stems were custom made cementless stems.

Median follow up was 3.8 years (range 0–34 years). Implant survival was 87% at 10 years, 61.6% at 20 years and 52.8% at 30 years.

PROMS demonstrated mean preoperative OHS was 12, preoperative MHHS was 23 and EQ5Ds VAS of 38. PROMS improved steadily overtime with mean OHS of 43, MMHS of 75 and EQ5Ds VAS of 89 at one year.

THA was associated with a very large change in patient reported hip function and quality of life. In this study, THA delivered a long-lasting solution to hip pain with survival similar to that seen in patients undergoing THA in the fourth and fifth decades of life. Socioeconomic benefits of THA need further investigation to establish treatment guidelines for children suffering with hip pain.

Total hip arthroplasty (THA) is often performed in symptomatic patients with developmental dysplasia of the hip (DDH) who do not qualify for periacetabular osteotomy (PAO). The impact of osteoarthritis (OA) severity on postoperative outcomes in DDH patients who undergo THA is not well described. We hypothesized that DDH patients who undergo THA with mild OA have slower initial recovery postoperatively, but similar one-year patient reported outcome measures (PROMs) when compared to DDH patients with severe OA.

We performed a retrospective review at a single academic institution over a six-year period of patients with DDH who underwent primary THA and compared them to patients without DDH who underwent THA. Within the DDH cohort, we compared PROMs stratified by DDH severity and OA severity. Diagnosis of DDH was verified using radiographic lateral center edge angle (LCEA). Minimum one-year follow-up was required. PROMs were collected through one-year postoperatively. Logistic and linear regression models were used adjusting for age, sex, body mass index, and Charlson Comorbidity Index.

263 patients with DDH were compared to 1,225 THA patients without DDH. No significant differences were found in postoperative PROMs or revision rates (p=0.49). When stratified by DDH severity, patients with LCEA<10° had worse preoperative pain (p=0.01), mental health (p<0.01) and physical function (p=0.03) scores but no significant difference in postoperative PROMs. Within the DDH group, when stratified by OA severity, patients with Grade 3 Tonnis score had worse preoperative pain (p=0.04) but no significant difference in postoperative PROMs. Recovery curves in DDH patients based upon severity of DDH and OA were not significantly different at 2-weeks, 6-weeks and 1-year.

DDH patients who have mild OA have similar recovery curves compared to those with severe OA. THA is reasonable in symptomatic DDH patients who have mild arthritis and do not qualify for PAO.

In primary total hip arthroplasty (THA) for patients with Crowe II or higher classes developmental dysplasia of the hip (DDH) or rapidly destructive coxopathy (RDC), the placement of the cup can be challenging due to superior and lateral acetabular bone defects. Traditionally, bone grafts from resected femoral heads were used to fill these defects, but bulk graft poses a risk of collapse, especially in DDH with hypoplastic femoral heads or in RDC where good quality bone is scarce. Recently, porous metal augments have shown promising outcomes in revision surgeries, yet reports on their efficacy in primary THA are limited.

This study retrospectively evaluated 27 patients (30 hips) who underwent primary THA using cementless cups and porous titanium acetabular augments for DDH or RDC, with follow-up periods ranging from 2 to 10 years (average 4.1 years). The cohort included 22 females (24 hips) and 5 males (6 hips), with an average age of 67 years at the time of surgery.

The findings at the final follow-up showed no radiographic evidence of loosening or radiolucency around the cups and augments, indicating successful biological fixation in all cases. Clinically, there was a significant improvement in the WOMAC score from an average of 39.1±14.7 preoperatively to 5.1±6.4 postoperatively. These results suggest that the use of cementless cups and porous titanium acetabular augments in primary THA for DDH and RDC can lead to high levels of clinical improvement and reliable biological fixation, indicating their potential as a viable solution for managing challenging acetabular defects in these conditions.

Total hip arthroplasty (THA) for congenital hip dysplasia (CDH) presents a challenge. In high-grade CDH, key surgical targets include cup placement in the anatomical position and leg length equality. Lengthening of more than 4 cm is associated with sciatic nerve injury, therefore shortening osteotomies are necessary. We present our experience of different shortening osteotomies including advantages and disadvantages of each technique.

89 hips, in 61 pts (28 bilateral cases), for high CDH were performed by a single surgeon from 1997 to 2022. 67 patients were female and 22 were male. Age ranged from 38 to 68 yrs. In all patients 5–8cm of leg length discrepancy (LLD) was present, requiring shortening femoral osteotomy. 12 patients underwent sequential proximal femoral resection with trochanteric osteotomy, 46 subtrochanteric, 6 midshaft, and 25 distal femoral osteotomies with simultaneous valgus correction were performed. All acetabular prostheses were placed in the true anatomical position. We used uncemented high porosity cups. Patients were followed up for a minimum of 12 months.

All osteotomies healed uneventfully except 3 non-unions of the greater trochanter in the proximal femur resection group. No femoral shaft fractures in proximally based osteotomies. No significant LLD compared to the unaffected or reconstructed side. 2 patients suffered 3 and 5 degrees malrotation of the femur in the oblique sub-trochanteric group. 3 patients suffered transient sciatic nerve palsies.

Shortening femoral osteotomies in the treatment of DDH are necessary to avoid injury to the sciatic nerve. In our series, we found transverse subtrochanteric osteotomies to be the most technically efficient, versatile and predictable in their clinical outcome, due to the ability to correct rotation and preserve the metaphyseal bone integrity, allowing for better initial stem stability. Distal femoral osteotomies allowed for controllable correction of valgus knee deformity.

Literature data show varying rates of aseptic loosening of standard hemispherical cups after primary total hip arthroplasty (THA) in patients with Crowe IV developmental dysplasia of the hip (DDH). In order to improve the results regarding the frequency of aseptic loosening of the acetabular component, we decided to use custom-made acetabular implants (CMAI) in this category of patients. The aim of our study was to report outcomes after primary THA using CMAI in patients with Crowe IV DDH.

We retrospectively analyzed the results of primary THA using the CMAI in 58 hips. The mean follow-up period was 5.2 years (range 4.2 – 6.3).

Patients demonstrated improved functional outcomes according to the Oxford Hip Score: preoperatively 16.9 and postoperatively 38.5 (P < 0.05). Revisions were performed in 2 cases due to dislocations, in 1 case due to nonunion of the greater trochanter and in 1 case due to chronic pain syndrome caused by contact of the CMAI flange with the iliopsoas muscle. In a patient with chronic pain syndrome, during the revision, the pubic flange of the CMAI, which was in contact with the iliopsoas muscle, was removed. There were no radiological signs of loosening of the CMAI.

The use of CMAI shows good results in patients with DDH. Extended capability for supplementary screw fixation is an excellent feature of such implants, allowing them to obtain reliable primary fixation. Further observation is required to assess CMAI in the long-term follow-up.

Securing the osteotomized greater trochanter (GT) during total hip arthroplasty (THA) for dislocated dysplastic hips (DDH) poses a significant challenge. This study evaluates the union rate and effectiveness of a 2-strand transverse wiring technique utilizing the lesser trochanter for wire anchorage and tensioning.

A digastric anterior slide trochanteric osteotomy was performed in 106 patients (118 hips) undergoing THA for DDH. Following uncemented stem insertion, the GT was transferred and fixed to the lateral cortex of the proximal femur using monofilament stainless steel wires. In 72 out of 106 patients (80 hips), the GT was fixed with 2 transverse wire cerclages threaded through 2 drill holes in the base of the lesser trochanter, spaced vertically 5–10 millimeters apart. The wires were wrapped transversely over the GT and tightened, avoiding contact with its tendinous attachments. Patients were regularly monitored, and GT union was assessed clinically and radiographically.

Patient ages ranged from 20 to 57 years (mean 35.5), with a follow-up period ranging from 1.5 to 12 years (mean 6.2). The mean union time was 3.3 months (range 2–7). Among all hips, two developed stable nonunion and single wire breakage, but no fragment displacement (2.5%). Two hips exhibited delayed union, eventually healing at 6 and 7 months after surgery.

Reattachment of the greater trochanter utilizing a 2-strand transverse wire cerclage anchored at the base of the lesser trochanter demonstrated a high rate of union (97.5%) following THA in dislocated DDH cases.

There is still no clear consensus regarding which cup position might provide better functional performance for developmental dysplasia of the hip (DDH). This study aimed to evaluated the feasibility and efficacy of acetabular mirroring reconstruction for DDH in total hip arthroplasty (THA).

The study reviewed 96 patients (96 hips) with unilateral Crowe type-II/III DDH undergoing either visualized navigation-assisted mirroring reconstruction with augment according to the rotation center and biomechanical structure of the contralateral normal hips (Mirroring group, 51 hips) or high hip center reconstruction (HHC group, 45 hips) in THA from 2020 to 2023. The functional and radiographic results were analyzed between the groups during a mean follow-up period of 27.5 and 28.9 months (a minimum follow-up of 12 months).

The Harris hip score at the last follow-up significantly improved in both groups, while it was significantly higher in the mirroring group (P<0.001). In the HHC group, the rotation center height and greater trochanter height were significantly increased in the affected hip (P<0.001; P<0.001) and the abductor lever arm was significantly decreased in the affected hip compared to that in the contralateral normal hip (P<0.001), whereas in the mirroring group no significant statistical differences were observed between two sides. The limping occurred in 7 patients (13.7%) in the mirroring group and 14 patients (31.1%) in the HHC group (P=0.040). A multiple logistic regression demonstrated mirroring reconstruction could reduce the incidence of postoperative limping (P=0.020).

Both mirroring and HHC reconstruction could improve the functional performance of THA, whereas mirroring reconstruction could offer superior biomechanical results and gait improvement as compared with HHC reconstruction, meeting the higher requirements of functional recovery.

Spasticity used to be considered a contraindication for total hip replacement (THR) procedures. Due to the development of implants as well as surgical skills, THR became an option for the treatment of painful dislocation of the hip joint in patients with spastic plegia. The aim of this study was an evaluation of mid-term results of THR in spastic CP adolescent patients with painful hips with hip joint subluxation or dislocation.

In 2014–2022, 18 pts (19 hips) with CP aged 16 to 20 years underwent THR in our department. The mean follow-up was 4 years (range: 1 – 9 years). Results were evaluated using the Gross Motor Function Scale, VAS scale in accordance with the Ashworth scale, types of implants used (dual mobility cup and not dual mobility cup), and radiological assessment (Crowe scale). Complications have been thoroughly analyzed.

In 10 pts there has been an improvement in the GMFSC scale average from 1 to 2 points observed after the surgery. All pts have improved in the VAS scale average of 8 points (from 10 to 7). According to the Crowe scale repositioning of preoperative dislocation to primary acetabulum was achieved in all cases. Complications occurred in 4 cases: dislocations of 2 THR with dual mobility cup and 2 THR with non-dual mobility cup requiring revision surgery with good final result. No statistical significance was noted according to the type of cup (Mann-Whitney U Test).

The most important risk factor for complications is severe spasticity. We believe, that CP pts with painful hips should be treated using THR. We didn't observe any significant differences between the types of implants.

These findings may serve as a basis for the prediction of outcomes of THR treatment in this specific group of pts.

Level of evidence: Case-control or retrospective comparative study-Level III

Angular proximal femoral deformities increase the technical complexity of primary total hip arthroplasties (THAs). The goals were to determine the long-term implant survivorship, risk factors, complications, and clinical outcomes of contemporary primary THAs in this difficult cohort.

Our institutional total joint registry was used to identify 119 primary THAs performed in 109 patients with an angular proximal femoral deformity between 1997 and 2017. The deformity was related to previous femoral osteotomy in 85%, and developmental or metabolic disorders in 15%. 53% had a predominantly varus angular deformity. The mean age was 44 years, mean BMI was 29 kg/m², and 59% were female. An uncemented metaphyseal fixation stem was used in 30%, an uncemented diaphyseal fixation stem in 28%, an uncemented modular body stem with metaphyseal fixation sleeve in 24%, and a cemented stem in 18%. Simultaneous corrective femoral osteotomy was performed in 18%. Kaplan-Meier survivorships and Harris hip scores were reported. Mean follow-up was 8 years.

The 10-year survivorships free of femoral loosening, aseptic femoral revision, any revision, and any reoperation were 95%, 93%, 90% and 88%, respectively. Revisions occurred in 13 hips for: aseptic femoral component loosening (3), stem fracture (2), dislocation (2), aseptic acetabular loosening (2), polyethylene liner exchange (2), and infection (2). Preoperative varus angular deformities were associated with a higher risk of any revision (HR 10, p=0.03), and simultaneous osteotomies with a higher risk of any reoperation (HR 3.6, p=0.02). Mean Harris hip scores improved from 52 preoperatively to 82 at 10 years (p<0.001).

In the largest series to date of primary THAs in patients with angular proximal femoral deformities, we found a good 10-year survivorship free from any revision. Varus angular deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher reoperation rate.

Keywords: Proximal femoral deformity; dysplasia; femoral osteotomy; survivorship; revision

Level of evidence: Level III, comparative retrospective cohort

The increased demand for total hip arthroplasty (THA) is having a significant impact on healthcare resources, resulting in increased interest in outpatient care pathways to reduce resource consumption. This study compared costs between patients who underwent outpatient THA using a Direct Anterior (DA) approach compared to a Direct Lateral (DL) approach to understand the effect of surgical approach on resource use.

We conducted a prospective randomized controlled trial for DA patients undergoing primary THA. We compared patients in the outpatient arm of the trial to a prospective cohort of outpatient DL approach THAs. We recorded all costs including: equipment, length of stay in hospital, and laboratory or other medical tests. Following discharge, participants also completed a self-reported cost diary recording resource utilization such as emergency department visits or subsequent hospitalizations, tests and procedures, consultations or follow-up, healthcare professional services, rehabilitation, use of pain medications, informal care, productivity losses and out of pocket expenditures.

We report costs from both Canadian public health care payer (HCP) and a societal perspective. The HCP perspective includes any direct health costs covered by the publicly funded system. In addition to the health care system costs, the societal perspective also includes additional costs to the patient (e.g. physiotherapy, medication, or assistive devices), as well as any indirect costs such as time off paid employment for patients or caregivers.

We included 127 patients in the DA group (66.6 years old) and 51 patients in the DL group (59.4 years old) (p<0.01).

There were no statistically significant differences in costs between groups from both the healthcare payer (DA= 7910.19, DL= 7847.17, p=0.80) and societal perspectives (DA= 14657.21, DL= 14581.21, p=0.96)

In patients undergoing a successful outpatient hip replacement, surgical approach does not have an effect on cost from in hospital or societal perspectives.

Proponents of the direct anterior approach (DAA) for hip arthroplasty (THA) claim lower postoperative pain compared to the posterolateral approach (PA); however, whether that theoretical advantage results in lower opioid consumption is unclear. We sought to investigate the relationship between the DAA and PA on total 90-day predicted opioid consumption in a large cohort.

Retrospective analysis identified 2,304 DAA and 6,288 PA primary THAs in patients >18 years old from February 2019 to April 2022. Ninety-day postoperative total morphine milligram equivalent (MME); in-hospital administration, discharge prescriptions, and refills within 90 days were compared between DAA and PA cohorts. Nearest-neighbor matching was performed controlling for age, sex, BMI, ASA, and periarticular injection to evaluate opioid consumption patterns for DAA and PA. Quantile regression was employed to predict the median (50th percentile) MME prescribed by surgical approach.

After matching, DAA and PA demonstrated similar median total 90-day prescribed MME (p = 0.008). After adjusting for patient and surgical factors, quantile regression predicted a similar median total 90-day prescribed MME for DAA and PA (243.5 versus 242.7; p = 0.78). While approach did not demonstrate a significant relationship for predicted 90-day MME, other factors including age, sex, BMI, length of stay, peripheral anesthesia, periarticular injection, and white or Caucasian race demonstrated a significant relationship with predicted 90-day MME (p <0.0001).

While we identified several risk factors for increased in-hospital and 90-day post-operative opioid consumption, a comparison between DAA and PA did not demonstrate significantly different opioid prescribing patterns.

The purpose of this study was to investigate the influence of surgical approach on femoral stem version in THA.

This was a retrospective database review of 830 THAs in 830 patients that had both preoperative and postoperative CT scans. All patients underwent staged bilateral THAs and received CT-based 3D planning on both sides. Stem version was measured in the second CT-scan and compared to the native neck axis measured in the first CT-scan, using the posterior condyles as the reference for both. Cases were performed by 104 surgeons using either a direct anterior (DAA, n=303) or posterior (PA, n=527) approach and one of four stem designs: quadrangular taper, calcar-guided short stem, flat taper and fit-and-fill. Sub-analyses investigated changes in version for low (≤5°), neutral (5–25°) and high (≥25°) native version subgroups and for the different implant types.

Native version was not different between approaches (DAA = 12.6°, PA = 13.6°, p = 0.16). Overall, DAA stems were more anteverted relative to the native neck axis vs PA stems (5.9° vs 1.4°, p<0.001). This trend persisted in hips with high native version (3.2° vs -5.3°, p<0.01) and neutral native version (5.3° vs 1.3°, p<0.001), but did not reach significance in the low native version subgroup (8.9° vs 5.9°, p=0.13). Quadrangular taper, calcar-guided, and flat taper stem types had significantly more anteversion than native for DAA, while no differences were found for PA.

Stems implanted with a direct anterior approach had more anteversion than those implanted with a posterior approach. The smaller surgical field, soft tissue tension and lack of a “tibial” vertical reference frame may contribute to this finding.

The direct anterior approach (DAA) is a popular minimally invasive approach for total hip arthroplasty (THA). It usually involves ligation of the lateral femoral circumflex artery's ascending branch (a-LFCA), which contributes to the perfusion of the tensor fasciae latae (TFL) muscle. Periarticular muscle status and clinical outcome were assessed after DAA-THA after a-LFCA preservation versus ligation.

We evaluated surgical records of 161 patients undergoing DAA-THA with tentative preservation of the a-LFCA by the senior author between May and November 2021. Among 92 eligible patients, 33 (35 hips) featured successful preservation, of which 20 (22 hips, 13 female) participated in the study. From 59 patients with ligated a-LFCA, 26 (27 hips, 15 female) were enrolled, constituting the control group. MRI and clinical examinations were performed at 17–26 months to analyze volume and fatty infiltration of the TFL, gluteus medius and gluteus minimus muscles relative to the contralateral non-THA hip (15 preserved, 18 ligated). Clinical and radiographic data was retrospectively extracted from patient files. Patient-reported outcomes (PROMs) were added from the THA registry.

There was a relative difference in TFL muscle volume of -6.27 cm³ (−9.89%, p=0.018) after a-LFCA preservation versus -8.6 cm³ (=11.62%, p=0.002) after ligation, without group differences (p>0.340). a-LFCA preservation showed lower relative TFL fatty infiltration (p=0.10). Gluteal muscle status was similar between sides and groups. Coxa valga morphology was more frequent in a-LFCA preservation (83%) than ligation (17%). Clinical outcomes showed high patient satisfaction in both groups, without difference in PROMs, but less anterolateral soft-tissue swelling after a-LFCA preservation (p<0.001).

Despite excellent clinical results in both groups, preservation of the a-LFCA was associated with less TFL fatty infiltration and soft tissue swelling. Provided there is no compromise of intraoperative access we recommend a-LFCA preservation for DAA-THA.

The direct superior approach (DSA) is a modification of the posterior approach (PA) that preserves the iliotibial band and short external rotators except for the piriformis or conjoined tendon during total hip arthroplasty (THA). The objective of this study was to compare postoperative pain, early functional rehabilitation, functional outcomes, implant positioning, implant migration, and complications in patients undergoing the DSA versus PA for THA.

This study included 80 patients with symptomatic hip arthritis undergoing primary THA. Patients were prospectively randomised to receive either the DSA or PA for THA, surgery was undertaken using identical implant designs in both groups, and all patients received a standardized postoperative rehabilitation programme. Predefined study outcomes were recorded by blinded observers at regular intervals for two-years after THA. Radiosteriometric analysis (RSA) was used to assess implant migration.

There were no statistical differences between the DSA and PA in postoperative pain scores (p=0.312), opiate analgesia consumption (p=0.067), and time to hospital discharge (p=0.416). At two years follow-up, both groups had comparable Oxford hip scores (p=0.476); Harris hip scores (p=0.293); Hip disability and osteoarthritis outcome scores (p=0.543); University of California at Los Angeles scores (p=0.609); Western Ontario and McMaster Universities Arthritis Index (p=0.833); and European Quality of Life questionnaire with 5 dimensions scores (p=0.418). Radiographic analysis revealed no difference between the two treatment groups for overall accuracy of acetabular cup positioning (p=0.687) and femoral stem alignment (p=0.564). RSA revealed no difference in femoral component migration (p=0.145) between the groups at two years follow-up.

There were no differences between patients undergoing the DSA versus PA for THA with respect to postoperative pain scores, functional rehabilitation, patient-reported outcome measurements, accuracy of implant positioning, and implant migration at two years follow-up. Both treatment groups had excellent outcomes that remained comparable at all follow-up intervals.

The SPAIRE technique (Saving Piriformis And Internus, Repair Externus) was first described in 2016 and an approach to the hip in the interval between the inferior gemellus and quadratus femoris can be used for both hemi- and total hip arthroplasty.

The HemiSPAIRE technique in hip hemiarthroplasty for displaced intracapsular fractures has been compared with the standard lateral approach (advocated by NICE) in a pragmatic, superiority, multicentre, randomised controlled trial into postoperative mobility and function. This NIHR funded study was recruited between November 2019 and April 2022 and the results are reported in this presentation.

The author has used the SPAIRE technique in 1026 routine primary total hip replacements since February 2016. The technique is described along with results from NJR data.

SPAIRE is most challenging in patients with small anatomy, reduced offset, with an external rotation deformity. Particularly in these, but in all cases, MAKO robotic assistance facilitates accurate implantation of prostheses and precise recreation of biomechanics. The MAKO robot has been used in all cases since 2018 and SPAIRE/MAKO is now the standard of care in the author's practice.

To evaluate whether robotic-assisted tendon-sparing posterior approaches (piriformis sparing and SPAIRE), improve patient outcomes in total hip arthroplasty compared with a robotic-assisted standard posterior approach, the NIHR Efficacy and Mechanism Evaluation Programme has recently funded the HIPSTER trial (HIP Surgical Techniques to Enhance Rehabilitation). This is a single-centre, double-blinded, parallel three-arm, randomised, controlled, superiority trial; recruitment is in progress.

The greatest value of robotic assistance may be when it is used in combination with tendon-sparing surgery. Data is being gathered to evaluate whether the SPAIRE/MAKO technique confers benefits with regard the speed of post-op mobilisation as well as accelerated return to unrestricted function.

The objective of this study is to evaluate the effectiveness and safety of percutaneous tenotomy of the iliopsoas tendon with the aid of ultrasound in cadavers.

An anatomical and descriptive study of the technique of percutaneous tenotomy of the iliopsoas tendon guided by ultrasound and to share our experience in performing it and its reproducibility in clinical practice.

Out of 20 tenotomies, 17 were total, performed at the level of the superior border of the acetabulum. Three tenotomies were partial, with more than 75% of the tendon being sectioned in all three. During one of the tenotomies, there was a partial injury to the femoral nerve. Measurements were made of the distance between the site where the blade was inserted and the femoral nerve, a noble structure that would be at greater risk during the procedure, with an average distance of 8.4 millimeters.

Ultrasound-guided iliopsoas tendon release procedures have the ability to be performed in a cadaveric model, consistently achieving complete tendon release, except in cases of obesity, with minimal repercussions on adjacent structures, and require approximately 4 minutes to complete.

Few surgical techniques to reconstruct the abductor mechanism of the hip have been reported, with outcomes reported only from case reports and small case series from the centres that described the techniques. As in many of our revision THA patients the gluteus maximus was affected by previous repeat posterior approaches, we opted to reconstruct the abductor mechanism using a vastus lateralis to gluteus medius transfer.

We report the results of such reconstructions in seven patients, mean age 66 (range, 53–77), five females, presenting with severe abductor deficiency (MRC grade 1–2). Five patients had previous revision THA, two with a proximal femoral replacement, one patient had a primary THA after a failed malunited trochanteric fracture, and one patient had a native hip with idiopathic fatty infiltration of glutei of >90%. All patients had instrumented gait analysis, and surface electromyography (EMG) of the glutei, TFL, and vastus muscles simultaneously before surgery and at each post-op follow-up. Postoperatively, patients were allowed to weight bear as tolerated and were requested to wear an abduction brace for the first six weeks after surgery to protect the transfer.

All patients improved after surgery and reached an abductor power of 3 or more. All patients walked without support six months after surgery and were satisfied with the result. Abductor function continued to improve beyond one year of follow-up, and some patients reached an abductor power of 5. EMG demonstrated that the transferred vastus lateralis started firing synchronously with gluteus medius after three months post-surgery, suggesting adaptation to its new function. No knee extension weakness was recorded. One patient complained of lateral thigh numbness and was dissatisfied with the cosmetic look of her thigh after surgery.

Our preliminary results are encouraging and comparable with those achieved by the originators of the technique.

Hypermobility Spectrum Disorder (HSD or hEDS) is attributed to a collagen abnormality associated with excessive joint flexibility. Approximately 90% of females with hip dysplasia have hypermobility. Manifestations of hypermobility in various body systems are unique to every patient, affecting different tissues of the body with varying degrees of severity. Our purposes were to identify the manifestations of hypermobility across multiple body systems and to study the recognition of hypermobility in the medical literature of multiple specialties over multiple decades.

A literature search of the major medical disciplines for key words associated with HSD was performed. These specialties included gastroenterology, gynecology, neurology, psychiatry, oral-maxillofacial surgery, cardiology, and orthopaedic surgery. A specialty-specific impact factor (IF) score was calculated as the percentage of research articles that referenced hypermobility as a comorbidity over all articles within that specialty. Statistical differences were identified using single factor ANOVA with significance determined at p<0.05. We reviewed many published, specialty-specific manifestations of hypermobility, and describe them.

All six non-orthopaedic specialties demonstrated a continually increasing relative IF ratio throughout the study period with a peak impact average of 0.22 (p<0.05 compared with other time ranges). There was a 93.3% overall increase in IF scores from the 1992–1998 period to the most recent period examined (p<0.05).

Hypermobility is increasingly recognized as a significant health issue in multiple disciplines. Since dysplasia is associated with approximately 40% of all primary total hip arthroplasty cases, understanding the multi-system manifestations, and broad impact of hypermobility on patients, is relevant for every hip surgeon. We are expanding our research into other medical disciplines, including urology, ophthalmology, dermatology, clinical psychology, and others.

There is a limited literature available describing the various diagnostic modalities and treatment options for the management of subspine impingement (SSI). We developed a study to evaluate the clinical improvement at 1 year and 5 years, with iHOT 33 and HOS hip scores.

(1) Do patients with subspine compression improve with arthroscopic treatment clinically at short term follow-up (1 year)? (2) Is the improvement maintained in the mid-term (5 years)?

43 young patients with subspine compression (prominent anterior inferior iliac spine) treated arthroscopically between January 2010 and December 2021 were included. Patients completed the iHOT33, HOS-SPORT and HOS-ADL questionnaires before surgery, 1 year and 5 years follow up. We evaluated pre and postoperative differences at one year and at 5 years. Minimum Clinically Significant Difference (MCID) and the Substantial Clinical Benefit (SCB) were used to stablish clinical improvement.

Mean age was 37.38 years and 66% were males. Almost 75% and 70% of our patients exceed the MCID and the SCB respectively in all the questionnaires after 1 year-follow up. However, at 5 years-follow up, nearly 70% and 65% of the patients exceeded MCID and SCB respectively.

We demonstrate that arthroscopic treatment of subspine impingement as an effective treatment for Subspine impingement. However, it is necessary larger sample size and longer follow up period to analyze the long-term results to demonstrate this treatment as the “gold standard”.

Osteonecrosis of the femoral head after femoral neck fracture (ONFHpoFNFx) poses challenges in children, particularly at Ficat III stage. Limited effective treatments are available. This study explores basicervical femoral neck rotational osteotomy (BFNRO) for ONFHpoFNFx in children and adolescents and evaluates its outcomes.

Children and adolescents with ONFHpoFNFx (Ficat stage III) underwent BFNRO at our center from June 2017 to September 2022 were included. Follow-up exceeded 1 year, with data on modified-Harris-hip-score (mHHS), range of motion (ROM), patient satisfaction, femoral head collapse, necrotic area repair, leg-length, and osteoarthritis progression recorded.

This study included 15 cases (15 hips), with 8 males and 7 females, averaging 12.9 years in age (range: 10–17 years). Nine cases had BFNRO alone, and six had combined PAO. Rotation angles varied from 70° to 90° for anterior rotation and 110° to 135° for posterior rotation. Nine patients had femoral neck fixation in a varus position (10° to 30°). The postoperative contour of the weight-bearing area of the femoral head has significantly improved in all patients. With an average follow-up of 28.6 months (range: 12.2–72.7 months), mHHS significantly improved (65.2 to 90.2, P<0.001). Only one patient showed femoral head collapse. Patients experienced no/mild hip pain (VAS=0-3), slight restriction in range of motion, and mild limb shortening. Two patients showed osteoarthritis progression. No infections, joint replacements, or nerve injuries were observed.

Even in cases of ONFHpoFNFx in the late stage, BFNRO in children and adolescents can still yield positive early to mid-term results by relocating the necrotic area and restoring the integrity of the anterior-lateral column of the femoral head, thereby preventing femoral head collapse and delaying the onset of severe osteoarthritis.

Bone marrow stem cells (BMSCs) represent a collection of different cell types exhibiting stem cell characteristics but with notable heterogeneity. Among these, Skeletal Stem Cells (SSCs) represent a distinct matrix subgroup within BMSC and demonstrate a specialized capacity to facilitate bone formation, recruit chondrocytes, and contribute to hematopoiesis. SSCs play a pivotal role in orchestrating the functions of skeletal organs. Local ischemia has a significant impact on cell survival and function. We hypothesize that bone ischemia induces alterations in the differentiation potential of SSCs, consequently influencing changes in bone structure.

We mechanically dissected tissue from the necrotic segment in the femoral head and more normal appearing areas from the femoral neck of specimens from 5 patients diagnosed with osteonecrosis of the femoral head (ONFH). These tissues were enzymatically broken down into individual cell suspensions. Utilizing fluorescence-activated cell sorting (FACS) based on specific surface markers indicative of human skeletal stem cells (hSSC), namely CD45- CD235a- CD31- TIE2- Podoplanin (PDPN)+ CD146- CD73+ CD164+, we isolated a distinct cell population. Subsequent in vitro evaluations, focusing on clonogenicity, osteogenesis, and chondrogenesis were conducted to assess the functional prowess of these SSCs. Moreover, we introduced BMP2 at a concentration of 50ng/ml to SSCs extracted from necrotic regions to potentially reinstate their osteogenic capabilities.

We effectively isolated SSCs from both Necrotic and Non-necrotic Zones. We observed an augmented clonal formation capacity and chondrogenesis ability of SSCs isolated from the necrotic region, accompanied by a significant decline in osteogenic ability (P＜0.01), an effect not reversible even with the addition of BMP2.

Ischemia adversely affects the proliferation and function of SSCs, resulting in a diminished osteogenic capacity and an insensitivity to BMP2, ultimately leading to structural alterations in bone tissue.

Executing an extended retinacular flap containing the blood supply for the femoral head, reduction osteotomy (FHO) can be performed, increasing the potential of correction of complex hip morphologies. The aim of this study was to analyse the safety of the procedure and report the clinical and radiographic results in skeletally mature patients with a minimum follow up of two years.

Twelve symptomatic patients (12 hips) with a mean age of 17 years underwent FHO using surgical hip dislocation and an extended soft tissue flap. Radiographs and magnetic resonance imaging producing radial cuts (MRI) were obtained before surgery and radiographs after surgery to evaluate articular congruency, cartilage damage and morphologic parameters. Clinical functional evaluation was done using the Non-Arthritic Hip Score (NAHS), the Hip Outcome Score (HOS), and the modified Harris Hip Score (mHHS).

After surgery, at the latest follow-up no symptomatic avascular necrosis was observed and all osteotomies healed without complications. Femoral head size index improved from 120 ± 10% to 100 ± 10% (p<0,05). Femoral head sphericity index improved from 71 ± 10% before surgery to 91 ± 7% after surgery (p<0,05). Femoral head extrusion index improved from 37 ± 17% to 5 ± 6% (p< 0,05). Twenty five percent of patients had an intact Shenton line before surgery. After surgery this percentage was 75% (p<0,05). The NAHS score improved from a mean of 41 ± 18 to 69 ± 9 points after surgery (p< 0,05). The HOS score improve from 56 ± 24 to 83 ± 17 points after surgery (p< 0,05) and the mHHS score improved from 46 ± 15 before surgery to 76 ± 13 points after surgery (p< 0,05).

In this series, femoral head osteotomy could be considered as safe procedure with considerable potential to correct hip deformities and improve patients reported outcome measures (PROMS).

Level of evidence - Level IV, therapeutic study

Keywords - Femoral head osteotomy, Perthes disease, acetabular dysplasia, coxa plana

In 1997 the Birmingham Hip Resurfacing was introduced to address the needs of young active patients. Alternative designs were introduced to try and improve wear performance. The aim of this study was a comparative cohort study of two types of metal-on-metal bearing to determine the mechanism of failure at 15 years.

The study reviewed 91 Brimingham Hip Resurfacings (BHR) (Smith and Nephew) and 715 DUROM hip resurfacing (Zimmer) procedures in prior to 2009. Failure was defined as revision of either component for any reason. Kaplan-Meyer survivorship analysis performed. Routine follow-up with serum metal ion levels and radiographs.

Mean follow-up was 17.9 years (range 15.2 – 25.1). The mean age at operation was 51.6 years (SD 8.6, range 20.7 to 70.2), including 299 women (37.1%). The Birmingham resurfacing demonstrated 92.3% survivorship at 15 years (SE 2.8, 95% CI 3.9 – 7.8) and 90.0% at latest follow-up (SE 3.5, 95% CI 4.9 to 9.4). By comparison, the DUROM survivorship at 15 years was 89.1% at 15 years (SE 1.2, 95% CI 2.0 to 2.5) and 87.4% (SE 1.3, 95% CI 2.5 to 2.3) at latest follow-up. There was no statistically significant difference in survivorship between groups (p= 0.32). Survival in male patients was 92.7% compared to 80.0% in females. The reported failures occurred from Adverse Reaction to Metal Debris (32 patients), periprosthetic femoral neck fracture (6) and aseptic loosening (41), PJI (12) and undiagnosed pain (6). The mean cobalt and chromium levels at last follow-up were 33.4 nmol/L and 36.5 nmol/L respectively.

This study demonstrates two differently designed metal-on-metal hip resurfacing provided a durable alternative to total hip replacement, particularly in younger male patients with osteoarthritis. Differences in design did determine the reason for revision with acetabular fixation being one of the principal failure mechanisms for the DUROM compared to elevated ion levels.

We previously reported the five to ten-year results of the Birmingham Hip Resurfacing (BHR) implant. The purpose of this study was to evaluate the survivorship, radiographic results, and clinical outcomes of the BHR at long-term follow-up.

We retrospectively reviewed 250 patients from the original cohort of 324 BHRs performed from 2006 to 2013 who met contemporary BHR indications. Of these, 4 patients died and 4 withdrew. From the 242 patients, 224 patients (93%) were available for analysis. Modified Harris hip score (mHHS) and University of California, Los Angeles (UCLA) scores were collected and compared to a matched total hip arthroplasty (THA) cohort. Mean follow-up was 14 years.

Survivorship free of aseptic revision was 97.4% and survivorship free of any revision was 96.0% at 15 years. Revisions included 3 periprosthetic joint infections, 2 for elevated metal ions and symptomatic pseudotumor, 2 for aseptic femoral loosening, and 1 for unexplained pain. The mean mHHS was 93 in BHR patients at final follow-up, similar to the THA cohort (p=0.44). The UCLA score was significantly higher for BHR patients (p=0.02), however there were equal proportions of patients who remained highly active (UCLA 9 or 10) in both groups, 60.5% and 52.2% (p=0.45) for BHR and THA respectively. Metal ion levels at long term follow-up were low (mean serum cobalt 1.8±1.5 ppb and mean serum chromium 2.2±2.0 ppb).

BHR demonstrated excellent survivorship in males less than 60 years of age at time of surgery. Clinical outcomes and activity levels were similar to THA patients. Failures related to the metal-on-metal bearing were rare and metal levels were low at long-term follow-up.

Level of evidence: III

Keywords: survivorship; hip arthroplasty; activity; metal-on-metal

Surface Replacement Arthroplasty demonstrates low revision rates and similar activity level compared to total hip arthroplasty at long-term follow-up.

Hip resurfacing arthroplasty (HRA) is being offered as a viable alternative to total hip arthroplasty (THA). For very young patients (under 30 years old), THA achieves fair results but with high revision and complication rates. This retrospective study was designed to evaluate the results of HRA performed in patients under 30 years old with a long follow-up.

During the inclusion period (2007–2021), we collected in a single operator database, all HRA performed in patients under 30 with a minimum follow up of 2 years.

103 HRA in 93 patients (77 male / 16 females; a mean age at operation 27.7 years (18 to 29.9)) were included. The two mean preoperative diagnoses were osteoarthritis in 54 HRA (52.5%) and DDH or hip dislocation in 19.4% (20 cases). No patient was lost to follow-up and 3 patients (5 HRA) deceased. There were 2 revisions (one for femoral aseptic loosening and one infection recurrence (pediatric osteoarthritis)). No dislocation and adverse wear-related failures were found. At a mean follow-up of 10.4 years (2–17.4), mean UCLA activity and Oxford Hip score improved respectively from 5.4 (1 to 7) and 39.9 (25–55) pre-operatively to 7.9 (3 to 10) and 15.8 (12–34) post-operatively (p<0.001). Mean Harris hip score increased from 41.6 (22–63) to 91.8 (72–100) (p<0.001). There were no radiological cases exhibiting lysis while two cases displayed limited partial radiolucency around the femoral stem. Kaplan-Meier survival analysis, with the endpoint revision for any reason, showed a 10.8-year survival rate of 98% (95% expected with NICE guidelines).

This cohort of HRA performed under 30 is the longest follow-up ever reported in the literature. Despite a challenging cohort of patients, HRA exceeds the stricter NICE survivorship criteria. HRA remains an effective treatment with excellent functional outcomes and a very low rate of complications.

A ceramic-on-ceramic hip resurfacing implant (cHRA) was developed and introduced in an MHRA-approved clinical investigation to provide a non metallic alternative hip resurfacing product. This study aimed to examine function and physical activity levels of patients with a cHRA implant using subjective and objective measures both before and 12 months following surgery in comparison with age and gender matched healthy controls.

Eighty-two unilateral cHRA patients consented to this study as part of a larger prospective, non-randomised, clinical investigation. In addition to their patient reported outcome measures (PROMs), self- reported measures of physical activity levels and gait analysis were undertaken both pre- operatively (1.5 weeks) and post operatively (52 weeks). This data was then compared to data from a group of 43 age gender and BMI matched group of healthy controls. Kinetics and kinematics were recorded using an instrumented treadmill and 3D Motion Capture. Statistical parametric mapping was used for analysis.

cHRA improved the median Harris Hip Score from 63 to 100, Oxford Hip score from 27 to 48 and the MET from 5.7 to 10.3. cHRA improved top walking speed (5.75km vs 7.27km/hr), achieved a more symmetrical ground reaction force profile, (Symmetry Index value: 10.6% vs 0.9%) and increased hip range of motion (ROM) (31.7° vs 45.9°). Postoperative data was not statistically distinguishable from the healthy controls in any domain.

This gait study sought to document the function of a novel ceramic hip resurfacing, using those features of gait commonly used to describe the shortcomings of hip arthroplasty. These features were captured before and 12 months following surgery. Preoperatively the gait patterns were typical for OA patients, while at 1 year postoperatively, this selected group of patients had gait patterns that were hard to distinguish from healthy controls despite an extended posterior approach. Applications for regulatory approval have been submitted.

Controversy persists over whether cemented or uncemented fixation is more effective in reducing revision and mortality risks following primary total hip arthroplasty (THA). Despite a shift towards uncemented THA in Europe, Australia, and the US, no consensus exists on superior outcomes. This ambiguity in evidence from randomized controlled trials (RCTs) and observational studies necessitates advanced research methodologies to derive more definitive conclusions.

This study investigates the causal impact of THA fixation type on 2-year and 5-year revision rates, along with 90-day mortality, utilizing a regression discontinuity (RD) design in scenarios where fixation choice is guided by patient age.

Employing data from the Dutch Arthroplasty Register, we conducted a cohort study on primary THAs for osteoarthritis from 2007 to 2019. A “fuzzy” RD design was executed to compute the Local Average Treatment Effect for subjects around the age-based selection threshold for fixation type. The main outcome of interest was the revision rate at 2 years post-operation.

Analysis for the 2-year revision endpoint, covering any cause, included 2,344 females and 1,671 males across 5 hospitals each, with no significant variation in revision rates observed. For the 5-year mark, 1,058 females in 3 hospitals and 214 males in 1 hospital were examined, similarly showing no significant differences. Mortality within 90 days post-operation was also investigated in 5 female and 7 male cohorts, with 2,180 and 2,145 surgeries respectively, yielding no substantial disparities.

In conclusion, the RD analysis revealed no notable differences in revision rates at 2 and 5 years or in early mortality based on the fixation method used in THA. These outcomes suggest that the age-based preference for THA fixation may not influence the revision or mortality risk, underscoring the value of RD design in deriving causal insights from observational data.

The stem design in total hip arthroplasty (THA) is constantly evolving. The impact of the collar on the risk of periprosthetic fracture remains controversial. This study aimed to determine whether adding a collar to the femoral stem impacts the early periprosthetic fracture risk within 90 days of surgery.

This retrospective study included 1,623 patients who underwent primary total hip arthroplasty in a single orthopedic department between January 2010 and December 2020. The inclusion criteria were uncemented stem with or without a collar, in a primary intention, without previous hip surgery with a similar “corail like” design. The assessed data were demographic characteristics (age, gender, number of obese (BMI > 30)), single or dual mobility, the surgical approach, the early complication, particularly the periprosthetic femoral fractures. Of the 1,623 patients, 1,380 received a collared stem (85%), and 243 received a collarless stem (15%). A multivariate analysis was performed to determine the collar's effect on the risk of early periprosthetic fracture (<90 days).

Nine (0.55%) early periprosthetic fractures were identified in the whole cohort. There were four fractures (1.65%) in the collarless stem group and five fractures (0.36%) in the collared stem group (p=0,005). One patient required revision surgery in the collared stem group, while two patients required revision surgery in the collarless stem group. The multinomial logistic regression model indicated a statistically significant lower (p<0.05) risk of early periprosthetic fracture within 90 days of surgery in the collared stems group. No other risk factor for early periprosthetic fractures has been identified.

Using collared stems in cementless THA protects early periprosthetic femoral fractures within 90 days of surgery.

Periprosthetic femoral fractures (PFFs) remain a major concern following cementless total hip arthroplasty (THA). This study aimed to evaluate the association between different types of cementless tapered stems and the risk of postoperative PFF.

A retrospective review of primary THAs performed at a single center from January 2011 to December 2018 included 3,315 hips (2,326 patients). Cementless stems were classified according to their design geometry using the system proposed by Radaelli et al. The incidence of PFF was compared between flat taper porous-coated stems (type A), rectangular taper grit-blasted stems (type B1), and quadrangular taper hydroxyapatite-coated stems (type B2). Multivariate regression analyses were performed to identify independent factors related to PFF. The mean follow-up duration was 61 months (range, 12‒139 months).

Overall, 45 (1.4%) postoperative PFFs occurred. The incidence of PFF was significantly higher in type B1 stems than in type A and type B2 stems (1.8 vs. 0.7 vs. 0.7%; P=0.022). Additionally, more surgical treatments (1.7 vs. 0.5 vs. 0.7%; P=0.013) and femoral revisions (1.2 vs. 0.2 vs. 0%; P=0.004) were required for PFF in type B1 stems. After controlling for confounding variables, older age (P<0.001), diagnosis of hip fracture (P<0.001), and use of type B1 stems (P=0.001) were significant factors associated with PFF.

Type B1 rectangular taper stems were found to have higher risks for postoperative PFF and PFF requiring surgical management than type A and type B2 stems in THA. Femoral stem geometry should be considered when planning for cementless THA in elderly patients with compromised bone quality.

Previous studies have highlighted differences in the risk of periprosthetic fracture between tapered slip (TS) and composite beam (CB) stems. This biomechanical study explored periprosthetic fractures around these stems and the effect of adding a 16-gauge calcar or diaphyseal wire to TS stems on their resistance to torque.

A power analysis determined a sample size of 7 specimens per group, assuming a standard deviation of 14.8 Nm in peak torque, to provide 90% power to detect a difference of at least 30 Nm between groups. Twenty-one TS stems (eight alone, six with calcar wiring, seven with diaphyseal wiring placed 2 cm distal to the lesser trochanter) and seven CB stems were cemented into standard Sawbones. A servo-hydraulic test machine applied a 1000 N load with a 1-degree rotation per second until failure. The peak torque at failure was measured, and the fracture location recorded. Comparisons were performed using two-sample t-tests.

CB stems exhibited a significantly higher peak torque at failure (205.3 Nm) than TS stems (159.5 Nm, p=0.020). Calcar-wire-TS (148.2 Nm, p=0.036) and diaphyseal-wire-TS (164.9 Nm, p=0.036) were both weaker than CB stems. Wired-TS stems showed no significant difference from non-wired-TS stems. Additionally, the study could not conclude that calcar wiring is stronger than diaphyseal wiring. All TS fractures occurred at the mid-stem, simulating a B-type fracture, while the addition of the diaphyseal wire shifted the fracture location more distally in four of seven stems (p=0.0699).

This biomechanical study supports the clinical evidence that CB stems have stronger resistance to torque than TS stems and may explain lower risk of periprosthetic fracture. The addition of calcar or diaphyseal wires to TS stems resulted in no significant changes in peak torque to fracture. In patients at high risk of periprosthetic fracture, CB cemented stems should be considered.

Short-stem total hip arthroplasty (THA) may have bone sparing properties, which could be advantageous in a younger population with high risk of future revision surgery. We used data from the AOANJRR, LROI and SAR to compare survival rates of primary THA, stems used in the first-time revision procedures as well as the overall survival of first-time revisions between a cohort of short-stem and standard-stem THA.

Short-stem THAs (designed as a short stem with mainly metaphyseal fixation) between 2007 and 2021 were identified (n=16,258). A propensity score matched cohort (1:2) with standard THAs in each register was identified (n=32,515). The cohorts were merged into a research dataset. Overall survival at 12 years follow-up was calculated using Kaplan-Meier survival analyses. Stem revisions (short-stem THA n=239, standard-stem THA n=352) were identified. The type of revision stem was classified as standard (<160 mm) or long (>160 mm). The survival rate of all first-time revisions in the two groups was calculated using any type of revision as outcome.

The 12 year- overall survival rate (all revisions, all causes) for primary short-stem THAs was 95.3% (CI 94.5–95.9%), which was comparable to 95.2% (CI 94.7–95.7%) for standard-stem THAs. In the short-stem THA group, a standard stem (<160 mm) was more often (59%) used in the first-time revision than in the standard-stem group (47%, p=0.004). The overall survival of the first-time revisions did not differ between cases primarily operated with a short or a standard stem.

In our multi-national register study, the overall survival rate of short stems was similar to that of standard stems. In short stem revisions there was a higher likelihood of using a standard-length stem for the revision compared with first-time revisions of standard stems. This finding might indicate bone-sparing properties with short-stemmed THAs.

Short stems have been developed to conserve bone stock, especially in younger populations undergoing a total hip arthroplasty (THA), and showed similar functional outcomes compared to conventional stems. Recent literature suggested that stem length might be an independent risk factor for acute periprosthetic femoral fracture in direct anterior THA (1) or with different short stem designs (2). The purpose of the present study was to compare the incidence of acute periprosthetic femoral fractures, between stems of the same manufacture (Taperloc microplasty vs Taperloc complete), which have the same stem characteristics, except for the stem length which is 35 mm shorter in Taperloc microplasty during posterior and lateral THA.

Our institution's arthroplasty database was searched for all primary total hip arthroplasties utilizing short femoral stems performed between August 2016 and August 2023. Pre-operative X-rays for each case were analysed to characterize the proximal femoral geometry, specifically the canal bone ratio (CBR) and canal flare index (CFI). Data analysis was performed to identify risk factors for periprosthetic fractures.

For the time period assessed, 2107 femoral stems (Taperloc Microplasty:1727, Taperloc complete: 380) were implanted. Females constituted 53% of the cohort. The average patient age was 70±11 years. The periprosthetic fracture rate was 0.94%, with 20 periprosthetic fractures (Taperloc Microplasty:17, Taperloc complete: 3) excluding 2 greater trochanteric fractures (1 at each group), identified at follow-up of three months. There was no significant difference between the periprosthetic fracture rates between the two stems (0.98% vs 0.79%, p>0.72) The multivariate regression analysis demonstrated that the stem length, CBR, CFI, age, and gender were not risk factors for periprosthetic fracture.

The present study demonstrated that both Taperloc Microplasty and Taperloc complete stems had similar rates of periprosthetic fractures, and the stem length was not a risk factor for a periprosthetic fracture during uncemented THA.

1. Tamaki T, Cementless Tapered-Wedge Stem Length Affects the Risk of Periprosthetic Femoral Fractures in Direct Anterior Total Hip Arthroplasty. J Arthroplasty. 2018 Mar;33(3):805-809. 2. Staunton P. Acute Periprosthetic Hip Fracture with Short Uncemented Femoral Stems. J Arthroplasty 2024 accepted.

Post-operative peri-prosthetic femoral fracture (PO-PPFF) is one of the most relevant complications in primary Total Hip Arthroplasty (pTHA), accountable for a significant clinical and socio-economic burden both in revision and fixation settings.

We retrospectively reviewed of our series of 1586 cementless total hip arthroplasty performed between 1999 and 2019 (achieving a minimum of 5-years follow-up) with different short stems.

We have observed a cumulative low incidence of PO-PPFF of 0,33% (5 cases): we divided Po-PPFF in two groups: fracture occurred around a short stem (A) and around a standard shortened stem (B), according to French Hip & Knee Classification of Short Stems.

Despite the length of observed period (mean follow-up 12 years, min 5 years max 24 years) a total of 1512 cases (mean age at surgery 61 years, max 74, min 40 years) were available to clinical and radiographic follow-up, being this population enrolled in elective surgery clinical protocols.

Our data exceed the low incidence of post-operative femoral fracture around bone -preserving previously reported by Kim in 2018 (12 fracture out of 1089 cases:1.1%).

No correlation have been observed among occurrence of PO-PPF age of the patient and no fracture occurred around cemented short stems despite patient's characteristics were unfavourable in term of age and bone quality. This result is not unexpected, giving the lower incidence of peri-prosthetic fracture even cemented conventional stems, as reported in all registry and systematic reviews.

A similar behaviour was reported in 2020 Australian Joint Registry, where Post-operative periprosthetic femoral fracture showed a steep curve in early period, but remaining firmly below 1% during the following 12 years.

Our clinical data seems to confirm previous studies by Jones (conducted on synthetic bone and fresh-frozen cadaveric femurs) where higher fracture angles and higher fracture torque were detected in short hips compared to standard stems.

A: - determine the incidence of intraoperative periprosthetic femoral fracture (PFF)

B: - determine the incidence of, and the reoperation rate for postoperative PFF

When using either CC or PTS femoral components.

Retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All PFFs were identified using regional radiograph archiving and electronic care systems.

Of the 11,018 THAs 4,952 were CC and 6,066 were PTS. Between groups, age, sex, and BMI did not differ.

A: - 55 (0.5%) had an intraoperative PFF. 44 CC and 11 PTS (p<0.001). 3 patients in each group had a femoral shaft fracture, remaining fractures were either the calcar (20 CC and 2 group) or the greater trochanter (11 CC and 6 PTS).

B: - 91(0.8%) sustained a postoperative PFF. Of those 15 were managed conservatively, 15 were revised and 61 (80.3%) had an ORIF. The CC group had both a lower overall rate of postoperative PFFs (0.7% (36/4,952) vs 0.9% (55/6,066); p = 0.341), and a lower rate of return to theatre (0.4% (22/4,952) vs 0.9% (54/6,066); p = 0.005). 1.3% of male PTS (36/2,674) had a reoperation compared to 0.3% of male CC (7/2,121) (p<0.001).

With regard to stem fracture there were none in the Corail group and 5 in the Exeter group. Of these 2 were sub trunnion and 3 were basal neck.

A: - There were significantly more intraoperative PFFs with CC 44 (0.8%) than PTS 11 (0.2%). However, the majority of fractures were either of the calcar or greater trochanter with no impact on early recovery or one year Oxford scores.

B: - Male PTS were five times more likely to have a reoperation for postoperative PFF. Females had the same incidence of reoperation with either component type.

There were 5 stem fractures in the Exeter group and none in the Corail.

These results represent robust estimates, which are likely to be more accurate than revision only studies typically generated from registry data.

The management of severe acetabular bone defects poses a complex challenge in revision hip arthroplasty. Although biological fixation materials are currently dominant, cage has played an important role in complex acetabular revision in the past decades, especially when a biological prosthesis is not available. The purpose of this study is to report the long-term clinical and radiographic results of Paprosky type Ⅲ acetabular bone defects revised with cage and morselized allografts.

We retrospectively analyzed 45 patients who underwent revision hip arthroplasty with cage and morselized allografts between January 2007 and January 2019. Forty-three patients were followed up. There were 19 Paprosky type IIIA bone defect patients and 24 Paprosky type IIIB bone defect patients and 7 patients of the 24 were also with pelvic discontinuity. Clinical assessment included Harris Hip Score (HHS) and Short Form-12 (SF-12). Radiographic assessment included cage stability, allografts incorporation, and center of rotation.

All patients were followed up with a mean follow-up of 10.6 years, HHS and SF-12 improved significantly at last follow-up in comparison to the preoperative. There were 2 re-revisions, one at 5 years after surgery, another at 13.6 years after surgery. Two patients had nonprogressive radiolucency in zone III and the junction of zone II and zone III at the bone implant interface. Allografts of 40 (93%) cases incorporated fully.

The combination of cage and morselized allograft is an alternative option for acetabular revision with Paprosky type III bone defects with satisfactory long-term follow-up results.

The Paprosky acetabular bone defect classification system and related algorithms for acetabular reconstruction cannot properly guide cementless acetabular reconstruction in the presence of porous metal augments.

We aimed to introduce a rim, points, and column (RPC)-oriented cementless acetabular reconstruction algorithm and its clinical and radiographic outcomes.

A total of 123 patients (128 hips) were enrolled. A minimum 5-year radiographic follow-up was available for 96 (75.8%) hips. The mean clinical and radiographic follow-up durations were 6.8±0.9 (range: 5.2–9.2) and 6.3±1.9 (range: 5.0–9.2) years, respectively.

Harris hip score (HHS) improved significantly from 35.39±9.91 preoperatively to 85.98±12.81 postoperatively (P<0.001). Among the fixation modes, 42 (32.8%) hips were reconstructed with rim fixation, 42 (32.8%) with three-point fixation without point reconstruction, 40 (31.3%) with three-point fixation combined with point reconstruction, and 4 (3.1%) with three-point fixation combined with pelvic distraction. Complementary medial wall reconstruction was performed in 20 (15.6%) patients. All acetabular components were radiographically stable. Nine-year cumulative Kaplan–Meier survival rates for 123 patients with the endpoint defined as periprosthetic joint infection, any reoperation, and dissatisfaction were 96.91% (confidence interval [CI]: 86.26%, 99.34%), 97.66% (CI: 92.91%, 99.24%), and 96.06% (CI: 86.4%, 98.89%), respectively.

Cup stability in cementless acetabular reconstruction depends on rim or three-point fixation. The continuity of the anterior and posterior columns determines whether the points provide adequate stability to the cup. Medial wall reconstruction is an important complementary fixation method for rim or three-point fixation. The patients who underwent cementless acetabular reconstruction guided by the RPC decision-making algorithm demonstrated satisfactory mid-term clinical function, satisfaction levels, radiographic results, and complication rates.

Chronic pelvic discontinuity (CPD) during revision hip arthroplasty is a challenging entity to address. The aim of this study was to evaluate the clinical and radiologic outcomes, and complications of the “acetabular distraction technique” for the management of CPD during revision hip arthroplasty.

Patients with CPD, who underwent acetabular revision between 2014 and 2022 at two tertiary care centres, using an identical distraction technique, were evaluated. Demographic parameters, pre-operative acetabular bone loss, duration of follow-up, clinical and radiologic outcomes, and survivorship were evaluated.

In all, 46 patients with a mean follow-up of 34.4 (SD=19.6, range: 24–120) months were available for evaluation. There were 25 (54.3%) male, and 21 (45.7%) female patients, with a mean age of 58.1 (SD=10.5, range: 40–81) years at the time of revision surgery. Based on the Paprosky classification of acetabular bone loss, 19 (41.3%), 12 (26.1%), and 15 (32.6%) patients had type 3b, 3a, and 2c defects. All patients were managed using the Trabecular Metal™ Acetabular Revision System; 16 patients required additional Trabecular Metal™ augments. The mean HHS improved from 50.1 (SD=7.6, range: 34.3 – 59.8) pre-operatively, to 86.6 (SD=4.2, range: 74.8 -91.8) at the last follow-up. Two patients (4.3 %) developed partial sciatic nerve palsy, two (4.3%) had posterior dislocation, and one (2.2%) required re-revision for aseptic loosening. Radiologically, 36 (78.3%) patients showed healing of the pelvic discontinuity. The Kaplan-Meier construct survivorship was 97.78% when using re-revision for aseptic acetabular loosening as an endpoint.

The acetabular distraction technique has good clinical and radiologic outcomes in the management of CPD during revision hip arthroplasty.

The objective of this study was to assess the clinical and radiological results of patients who were revised using a new generation custom-made triflange acetabular component (CTAC) for component loosening and large acetabular defect (Paprosky 3A and 3B) after previous total hip arthroplasty (THA). New generation CTACs involve the use of patient-specific drill guides and incorporate three-dimensional printed bone models, enhancing precision during surgical implantation.

Data were extracted from a single centre prospective database of patients with large acetabular defects who were treated with a new generation CTAC. Patients were included if they had a minimum follow-up of five years. The modified Oxford Hip Score (mOHS), EurQol EuroQoL five-dimension three-level (EQ-5D-3L) utility, and Numeric Rating Scale (NRS), including visual analogue score (VAS) for pain, were gathered at baseline, and at two- and five-year follow-up. Reasons for revision, and radiological and clinical complications were registered. Trends over time are described and tested for significance (p<0.05).

A total of 49 (70%) of 70 patients with a mean age of 73.5 years (SD 7.7) had a complete follow-up of 5 years. A significant improvement was found in HOOS, mOHS, EQ-5D-3L utility and NRS, VAS pain rest and activity between baseline and final follow-up. Complications included 8 cases with loosening screws, 4 with bony fractures, 4 periprosthetic infections and 2 cases with dislocation. One patient with bilateral pelvic discontinuity had revision surgery due to recurrent dislocations. No revision surgery was performed for screw failure or implant breakage.

New generation CTAC in patients with THA acetabular loosening and massive acetabular bone loss (Paprosky 3A and 3B) can result in stable constructs and significant improvement in functioning and health-related quality of life at five years’ follow-up.

There remains concern with the use of constrained liners (CL) implanted at the time of acetabular cup revision in revision total hip replacement (rTHA). The aim of this study was to determine the implant survival in rTHA when a CL was implanted at the same time as acetabular cup revision.

We reviewed our institutional database to identify all consecutive rTHAs where a CL was implanted simultaneously at the time acetabular cup revision from 2001 to 2021. One-hundred and seventy-four revisions (173 patients) were included in the study. Mean follow-up of 8.7 years (range two – 21.7). The most common indications for rTHA were instability (35%), second-stage periprosthetic joint infection (26.4%), and aseptic loosening (17.2%).

Kaplan Meier Analysis was used to determine survival with all-cause re-revision and revision for cup aseptic loosening (fixation failure) as the endpoints.

A total of 32 (18.3%) patients underwent re-revision at a mean time of 2.9 years (range 0.1 – 14.1). The most common reasons for re-revision were instability (14), periprosthetic joint infection (seven), and loosening of the femoral component (four). Three (1.7%) required re-revision due to aseptic loosening of the acetabular component (fixation failure) at a mean of two years (0.1 – 5.1). Acetabular component survival free from re-revision due to aseptic loosening was 98.9% (95% CI 97.3 – 100) at five-years and 98.1% (95% CI 95.8 – 100) at 10-years. There were no acetabular component fixation failures in modern highly porous shells.

CLs implanted at the time acetabular cup revision in rTHA have a 98.1% 10-year survival free from acetabular cup aseptic loosening (fixation failure). There were no cup fixation failures in modern highly porous shells. Thus, when necessary, implanting a CL during revision of an acetabular component with stable screw fixation is safe with an extremely low risk of cup fixation failure.

Implant fracture of modular revision stems is a major complication after total hip arthroplasty revision (rTHA). Studies looking at specific modular designs report fracture rates of 0.3% to 0.66% whereas fractures of monobloc designs are only reported anecdotally. It is unclear whether the overall re-revision rate of modular designs is higher and if, whether stem fractures or other revision reasons are responsible for this elevation.

All revisions within 5 years after implantation of a revision stems (n₀=13,900; n₅=2506) were analysed using Cox regression with design (modular: n=17, monobloc: n=27), BMI, Sex and Elixhauser Score as independent variables. One stage and two stage revisions were analysed separately (1-stage: modular n= 7,102; monobloc n= 4,542; 2-stage: 1,551 / 704). The revision volume of the hospitals was also considered (low: <20 revisions, medium: 21–50 revisions, high: >50 revisions).

For the 1-stage revisions, the re-revision risk after 4 years was 14,3% [13.2%, 15.5%] for monobloc and 17.4% [16.40%, 18.40%] for modular stems (p< 0.001). Stem fracture was the reason for re-revision in 2.4% of the modular (fracture rate 0.42%) and 0.6% of the monobloc revisions. The difference in re-revision rates between the designs was mainly due to differences in dislocation and stem loosening. For the 2-stage revisions, the revision risks for either design were similar (21.7% [18,5%, 25.4%] vs. 23.0% [20.8%, 25.4%]; p=0.05). Patient characteristics influenced the comparison between the two designs in the 1-stage group but very little in the 2-stage group.

Modular revision stem fractures only contribute very minor to re-revision risk. In 2-stage revisions, no difference in overall re-revision rates between designs was observed. This might indicate that the differences observed for 1-stage procedures are due to differences between the patient cohorts, not reflected by the parameters available or surgeon choice.

For over a decade, modular titanium fluted tapered (TFT) stems have demonstrated excellent clinical success for femoral revision total hip arthroplasty (THA) surgery. The aim of this study was to report the short-term outcomes of a novel modern monoblock TFT stem used for revision and complex primary THA with a minimum of 2 years follow-up.

We identified 126 patients who received a single monoblock TFT stem - 26 patients for complex THA (failed fracture fixation) and 100 patients for revision THA. The reasons for revision THA included 40 for previous prosthetic joint infection (PJI), 42 for aseptic loosening, 9 for trunnionosis, 9 for periprosthetic fractures. The Paprosky grading for femoral bone loss at the time of surgery and the measured subsidence of femoral stems at 3 months follow-up were determined. We evaluated the number and indications for re-operations.

The mean time from surgery was 3.9 years (range 2.0 to 6.9 years). A paired t-test analysis showed significant improvement from pre-operative versus post-operative clinical outcome scores (p<0.001) for HHS (38.76 +/- 15.24vs. 83.42 +/- 15.38), WOMAC (45.6 ± 19.0 vs. 69.9 ± 21.3) and SF-12 Physical component (31.7 ± 8.1 vs. 37.8 ± 11.3) and SF-12 Mental component (48.2 ± 12.2 vs. 51.6 ± 12.5). The Paprosky grading for femoral bone loss was Grade 1 (3.9%), Grade 2 (35.7%), Grade 3A (47.6%), Grade 3B (11.1%) and Grade 4 (1.6%) cases. There were 18 re-operations (14.7%) with 13 for PJI (7 treated with implant retention, 6 treated with a two-staged revision), 4 for instability and one for acetabular aseptic loosening. There were no aseptic failures of the stem.

This novel modern monoblock TFT stem provided reliable femoral fixation and has increasingly supplanted the use of modular TFT stems for complex primary and revision surgery in our institution.

Dislocation following revision THA remains a leading cause of failure. Integrity of the abductor muscles is a major contributor to stability. Large diameter heads (LDH), Dual Mobility (DM) and Constrained Acetabular Liners (CAL) are enhanced stability options but the indication for these choices remains unclear.

We assessed an algorithm based on Gluteus Medius (GM) deficiency to determine bearing selection. Default choice with no GM damage was a LDH. GM deficiency with posterior muscle intact received DM and CAL for GM complete deficiency with loss of posterior muscle.

Consecutive revision THA series followed to determine dislocation, all-cause re-revision and Oxford Hip Score (OHS).

311 revision THA with mean age 70 years (32–95). At a mean follow-up of 4.8 years overall dislocation rate 4.1% (95%CI 2.4–7.0) and survivorship free of re-revision 94.2% (95%CI 96.3–91.0). Outcomes:

Group 1 - LDH (36 & 40mm) n=164 / 4 dislocations / 7 re-revisions

Group 2 - DM n=73 / 3 dislocations / 4 re-revisions

Group 3 - CAL n=58 / 5 dislocations / 7 re-revisions

Group 4 - Other (28 & 32mm) n=16 / 1 dislocation / no re-revisions

Mean pre-op OHS: 19.6 (2–47) and mean post-op OHS: 33.9 (4–48). Kaplan-Meier analysis at 60 months dislocation-free survival was 96.1% (95% CI: 93.0–97.8). There was no difference between survival distributions comparing bearing choice (p=0.46).

Decision making tools to guide selection are limited and in addition soft tissue deficiency has been poorly defined. The posterior vertical fibres of GM have the greatest lateral stabiliser effect on the hip. The algorithm we have used clearly defined indication & implant selection. We believe our outcomes support the use of an enhanced stability bearing selection algorithm.

Total hip arthroplasty (THA) has proved to be an effective treatment modality for sickle-cell hip arthropathy (mosaic-like dense bone due to infarcts). However, mode of failure, survival rates and challenges associated with revision hip arthroplasty in sickle-cell disease patients are mostly unknown.

We retrospectively evaluated prospectively collected data from all patients with sickle-cell disease who underwent revision hip arthroplasty from 2016. Patient, surgery, medical and surgical complications related data were collected. The pinnacle and reclaim revision system with gription augments (JJ) was used in all patients. Pre-op and post-op clinical outcome data (both objective and subjective, HOOS Jr and OHS) were recorded. Cumulative success rates were recorded with re-revision surgery as an end point.

We performed fifteen revision THAs on 13 patients (mean follow up of 6.6 years). The mean age of the patients was 48 years (range, 30–59). At final follow-up, a statistically significant improvement of mean OHS and HOOS JR scores eas found in all patients. reported (OHS: 34.0 and HOOS JR: 77.7). Cumulative success rate was 100% for re-revision for all reasons at 6 years. Five intensive care unit (ITU) admissions, two vaso-occlusive sickle cell crises, one transfusion-related complication and one acute chest syndrome (ACS) were recorded. On admission, the mean percentage of HbS was 75.25% (64.6–86.4%).

Revision arthroplasty in sickle-cell disease patients poses increased risks, with medical and surgical challenges. However, with careful preparation, planning and a multi-disciplinary team approach, revision arthroplasty can result in excellent clinical outcomes and excellent functional scores in the majority of patients in the short and mid-term.

Extensive and severe bone loss of the femur may be a result of a failed total hip arthroplasty (THA) or total knee arthroplasty (TKA) with multiple revision surgeries which may be caused by factors such as infection, periprosthetic fracture or osteolysis. The aim of this study was to assess outcomes of using the “Push-Through Total Femoral Prosthesis” (PTTF) for revision of a total hip replacement with extreme bone loss.

Fourteen patients who had extensive bone defects of the femur due to failed THR's and were treated with PTTF between 2012 and 2020 were included in this study. Primary functional outcomes were assessed using Harris Hip Score (HHS), Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scores. Range of motion, complications, and ambulatory status were also recorded to assess secondary outcomes.

Two of 14 patients underwent surgery with PTTF for both knee and hip arthroplasty revision. The mean time between index surgery and PTTF was 15 years (3 to 32 yrs.). Acetabular components were revised in six of 14 patients. After a mean follow-up of 5.9 years, hip dislocations occurred in 3 patients. All dislocated hips were in patients with retained non-constrained acetabular bearings. Patient satisfaction was high (MSTS: 67%, HHS: 61.2%, TESS 64.6%) despite a high re-operation rate and minor postoperative problems.

PTTF is a unique alternative that may be considered for a failed THA revision procedure in patients with an extreme femoral bone defect. Patients are able to ambulate pain free relatively well. Routine usage of constrained liners should be considered to avoid hip dislocation which was our main problem following the procedure.

In total hip arthroplasty (THA), cementless cup without screw holes has the putative benefits of maximizing host bone contact and reducing osteolysis by eliminating channels to backside wear particles. However, supplemental trans-acetabular screws cannot be used.

74 hips in 60 patients receiving same model of cementless cup without screw holes (Depuy Duraloc 100 HA cup) from 6/1999 to 3/2003 were prospectively followed up. All patients were allowed to have immediate full weight bearing. Age at THA was 53 ± 13 (range 24–74) years. Osteonecrosis was the leading hip disease (45% of hips). Survivorship was assessed using revision of the cup as the end point. Radiological parameters, including lateral opening angle, vertical and horizontal migration distances of the cups were measured. Paired t-test was used to compare between the measurements in early postoperative period and at final follow up.

51 hips were assessed at minimum 20 years follow-up. The mean follow-up was 22.6 (range 21 – 25) years. All the cups were well fixed. There were two cup revisions. Conventional polyethylene (PE) was used in both hips; osteolysis occurred 17 and 18 years later. Both cups were well fixed but were revised, one due to cup mal-positioning, one due to need in upsizing the articulation. 14 other hips were revised but these cups were well fixed and not revised; 9 loosened stems (most were cemented Elite plus stems), 5 PE wear and osteolysis (all were conventional PE). At 20 years, the survivorship of cups was 96.1%. Changes in lateral opening angle, vertical and horizontal migration distances were 0.44±1.59°, 0.01±1.52mm and -0.32±1.47mm respectively, without statistical significance.

This study provided evidence of excellent long-term survivorship of cementless cup without screw holes. Immediate postoperative weight-bearing also did not lead to cup migration in the long-term.

We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by types of bearing surfaces used.

We analysed THR procedures across all orthopaedic units in England and Wales. Our analyses estimated all-cause and cause-specific revision rates. We identified primary THRs with heads and monobloc cups or modular acetabular component THRs with head and shell/liner combinations. We used flexible parametric survival models to estimate adjusted hazard ratios (HR).

A total of 1,026,481 primary THRs performed between 2003–2019 are included in the primary analysis (Monobloc: n=378,979 and Modular: n=647,502) with 20,869 (2%) of these primary THRs subsequently undergoing a revision episode (Monobloc: n=7,381 and Modular: n=13,488).

Compared to implants with a cobalt chrome head and highly crosslinked polyethylene (HCLPE) cup, the all-cause risk of revision for monobloc acetabular implant was higher for patients with cobalt chrome or stainless steel head and non-HCLPE cup. The risk of revision was lower for patients with a delta ceramic head and HCLPE cup implant, at any post-operative period.

Compared to patients with a cobalt chrome head and HCLPE liner primary THR, the all-cause risk of revision for modular acetabular implant varied non-constantly. THRs with a delta ceramic or oxidised zirconium head and HCLPE liner had a lower risk of revision throughout the entire post-operative period.

The all-cause and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is lower for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup than commonly used alternatives such as cobalt chrome heads and HCLPE liner/cup.

We present minimum 20 year results of a randomized, prospective double blinded trial (RCT) of cross-linked versus conventional polyethylene (PE), using a computer assisted method of PE wear measurement.

After Ethics Committee approval, 122 patients were enrolled into an RCT comparing Enduron (non cross-linked PE) and highly cross-linked Marathon PE (DePuy, Leeds, UK). Other than the PE liners, identical components were used, a Duraloc 300 metal shell with one screw, a 28mm CoCr femoral head and a cemented Charnley Elite femoral stem. All patients were followed with anteroposterior (A∼P) and lateral radiographs at 3 days, 6 weeks, 3 months, 6 months, 1, 2, 3, 4, 5, 10 and 20 years. PE wear was measured with PolyMig, which has a phantom validated accuracy of ± 0.09mm.

At minimum 20 year follow-up, 47 patients had died, 5 of which had been revised prior to their death. Another 32 patients were revised and alive, leaving 43 patients unrevised and alive (15 Enduron, 28 Marathon). No patients were lost to follow-up, but 2 were not able to be radiographed (dementia), leaving 41 patients (15 Enduron, 26 Marathon) available for PE wear measurement. After the bedding-in period, Enduron liners had a wear rate of 0.182 mm/year, and Marathon liners had a wear rate of 0.028 mm/year. At 20 years follow-up, 37 patients had required revision. Patients with conventional PE had three times the revision rate (28/37) of those who received XLPE (9/37).

This is the longest term RCT showing substantially improved clinical and radiological results when XLPE is used as the bearing surface.

Vitamin E-doped cross-linked polyethylene (VEPE) has encouraged the use of larger heads in thinner liners in total hip arthroplasty (THA). However, there are concerns about wear and mechanical failure of the thin liner, especially when metal heads are used. The aim of this randomized controlled trial was to investigate if the use of a large metal head in a thin VEPE liner would increase polyethylene wear compared with a standard 32-mm metal head and to compare periacetabular radiolucencies and patient-reported outcomes in THA.

96 candidates for uncemented THA were randomly allocated to either the largest possible metal head (36–44 mm) that could be fitted in the thinnest available VEPE liner (intervention group) or a standard 32-mm metal head (control group). The primary outcome was proximal head penetration (PHP) measured with model-based radiostereometric analysis (RSA). Secondary outcomes were periacetabular radiolucencies and patient-reported outcomes. The mid-term results of the trial at 5 years are presented.

Median total PHP (interquartile range) was -0.04 mm (−0.12 to 0.02) in the intervention group and -0.03 mm (=0.14 to 0.05) in the control group (p=0.691). The rates of periacetabular radiolucencies were 1/44 and 4/42 (p=0.197), respectively. Patient-reported hip function and health-related quality of life did not differ between the groups, but participants in the intervention group reported a higher level of activity (median UCLA rank 7 vs 6, p=0.020). There were 5 revisions caused by dislocations (2), periprosthetic fracture (1), stem subsidence (1), or iliopsoas impingement (1).

Large metal heads in thin VEPE liners did not increase liner wear and were not associated with liner failure 5 years after THA.

Highly cross-linked polyethylene (HXLPE) has decreased wear and revision rates in total hip replacement (THR) at a long-term. However, the effect of HXLPE manufacturing characteristics on femoral head penetration has not been clearly defined yet. We report this single-institution study to investigate the clinical and radiological results of different HXLPE liners in THR.

In this retrospective cohort analysis of our prospective database, we identified 904 THRs performed between 2000 and 2013. Seven different HXLPE liner types were assessed: remelted (3), annealed (2), sequentially annealed (1) and vitamin E-infused (1). The linear femoral head penetration rate was measured at six weeks, one year, and annually thereafter, using the Roman Software v1.70 package.

Thirty hips were revised for the following reasons: aseptic loosening (11), dislocation (12), periprosthetic femoral fracture (6), and infection (1). No hip was revised for wear or osteolysis. 741 THRs were evaluated for a mean follow-up of 15 years (range, 10 to 20). The mean total penetration 15 years after THR was 0.17 mm in the sequentially annealed, and 0.16 mm in the vitamin E-infused groups, whereas it was 0.26 mm in the melted 95 kGy, 0.27 mm in the melted 5 Mrad and 0.25 mm in the melted 100 kGy groups (p=0.001). From one to 15 years after surgery, the mean wear was 0.206 mm in cups with an acetabular inclination greater than 50º and 0.105 mm in those placed between 35º and 50º (p<0.001).

Although HXLPE characteristics can result in a different wear performance in patients undergoing THR at a mean follow-up of 15 years, the clinical results are excellent. The position of the acetabular component can influence on the femoral head penetration of modern HXLPEs. Nevertheless, these patients should continue to be monitored to detect future problems.

Hip resurfacing arthroplasty (HRA) is a bone conserving alternative to total hip arthroplasty. We present the early 2-year clinical and radiographic follow-up of a novel ceramic-on-ceramic (CoC) HRA in an international multi-centric cohort.

Patients undergoing HRA between September 2018 and January 2021 were prospectively included. Patient-reported outcome measures (PROMS) in the form of the Forgotten Joint Score (FJS), HOOS Jr, WOMAC, Oxford Hip Score (OHS) and UCLA Activity Score were collected preoperatively and at 1- and 2-years post-operation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis/loosening and heterotopic ossification formation.

200 patients were identified to have reached 2-year follow-up. Of these, 185 completed PROMS follow-up at 2 years. There was significant improvement in HOOS (p< 0.001) and OHS (p< 0.001) and FJS (p< 0.001) between the pre-operative and 2-year outcomes. Patients reported improved pain (p<0.001), function (p<0.001) and reduced stiffness (p<0.001) as measured by the WOMAC score. Patients had improved activity scores on the UCLA Active Score (P<0.001) with 53% reporting return to impact activity at 2 years. There was no osteolysis and the mean acetabular cup inclination angle was 41deg and the femoral component shaft angle was 137deg. No fractures were reported over but there was one sciatic nerve palsy with partial recovery. Two patients were revised; one at 3 months for pain due to a misdiagnosed back problem and another at 33 months for loosening of the acetabular component with delamination of the titanium ingrowth surface.

CoC resurfacing at 2-years post-operation demonstrate promising results with satisfactory PROMS.

Ceramic-on-ceramic (CoC) articulations in total hip arthroplasty (THA) have low wear, but the unique risk of fracture. After revision for CoC fracture, ceramic third bodies can lead to runaway wear of cobalt chrome (CoCr) causing extremely elevated blood cobalt. We present five cases of ceramic liner fractures revised to a CoCr head associated with the rapid development of severe cobalt toxicity.

We identified 5 cases of fractured CoC THA treated with revision to CoCr on highly cross-linked polyethylene (HXLPE) – three to conventional bearings and two to modular dual mobility bearings (CoCr acetabular liner, CoCr femoral head, and HXLPE). Mean follow up was 2.5 years after CoCr/HXLPE re-revision.

Symptoms of cobalt toxicity occurred at average 9.5 months after revision for ceramic fracture (range 6–12). All patients developed vision and hearing loss, balance difficulties, and peripheral neuropathy. Several had cardiomyopathy, endocrinopathy, and local skin discoloration. Two reported hip pain. Re-revision for cobalt toxicity occurred at an average of 22 months (range 10–36) after revision for ceramic fracture. Average serum cobalt level at re-revision was 991 μg/L (range 734–1302, normal <1 μg/L). All CoCr heads exhibited massive wear with asphericity; deep tissues exhibited prominent metallosis. Treatment consisted of debridement and revision to a ceramic head with HXLPE. Serum cobalt improved to an average of 25 μg/L at final follow up. All patients reported partial improvement in vision and hearing; peripheral neuropathy and balance did not recover.

Systemic cobalt toxicity is a rare but devastating complication of ceramic fracture in THA treated with cobalt-alloy bearings. Cobalt alloy bearings should be avoided in this setting. The diagnosis of systemic cobalt toxicity requires a high index of suspicion and was typically delayed following systemic symptoms. Debridement and revision to a ceramic-on-HXLPE leads to improvement but not resolution of cobalt toxicity complications.

The periacetabular osteotomy(PAO) is an effective common hip-preserving procedure to treat symptomatic acetabular dysplasia of the hip (DDH). The literature regarding truly long-term patient outcomes after PAO remains limited. We sought to evaluate our patient cohort treated by PAO 25 to 33 years ago to identify factors positively and negatively associated with durable therapeutic success.

219 dysplastic hips (183 patients) underwent PAO between August 1991 and December 1999 by a single surgeon. 164 hips in 134 patients were retrospectively evaluated at minimum of 25 years and maximum of 33 years post-operatively. Hips were evaluated using the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) postoperatively. Osteotomy failure was defined as WOMAC pain score of >/=10 or the need for total hip arthroplasty (THA). 7 patients (7 hips) had died - none of whom had THR. 142/176 remaining patients were located. All patients returned questionnaires; some were seen in person with images.

Of patients analyzed to date, 109 hips (63%) were asymptomatic/mildly symptomatic with a preserved hip. 58 hips (33%) had undergone THA. 7 preserved hips (5%) were symptomatic (WOMAC>10). Patients with THA were slightly older than asymptomatic patients (54 ± 8 years vs. 50 ± 11 years; p=0.08), as they had been at time of PAO. Most patients were female (83%), with 89% of hip replacement patients being female. 4/58 replaced hips had been revised - 3 for instability and 1 for acetabular loosening. Data collection is ongoing as more patients are located and reviewed.

Long-term follow-up of patients is challenging. Review after minimum of 25 years of the Boston cohort treated with PAO after minimum of 25 years dysplasia reveals that most at long-term follow-up report high levels of function, whether or not they had required arthroplasty, although 33% had required interim treatment with THA.

Pelvic osteotomies for hip dysplasia results can be variable and depend on the amount of preexisting arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a technique designed to measure early arthritis, and could be used to select hips that would benefit from a joint-preserving reconstructive procedure. Our objective was to investigate the role of preoperative dGEMRIC in predicting the success of PAO in patients 40 and above. We hypothesized that patients who failed had lower preoperative dGEMRIC index compared to those who did not.

Following IRB approval, patients 40 or older who underwent PAO between 1990–2013 and had preoperative dGEMRIC scan and minimum follow-up of 4 years were identified. Patients with prior hip surgeries or any pathologies were removed leading to a total of 70 patients (Age: 44.2 ± 2.9 years old, BMI: 25.7 ± 4.5 Kg/m²). We only included the first hip undergoing PAO for those with bilateral PAO. Out of 70, 19 had failure defined by the need for total hip replacement or WOMAC pain score of 10 and above within 10 years after index PAO surgery. Articular cartilage was segmented on the 3D pre-operative dGEMRIC scan. The average thickness and dGEMRIC index across the whole articular surface were analyzed.

Failed hips had a lower dGEMRIC index by 115 ± 20 ms (P<0.001). All but one failed hips had a dGMERIC index of 400 or less (range: 313 – 479 ms), while all survived hips had a dGMERIC index of greater than 400 (range: 403 – 691 ms). Similar trends were observed when comparing the dGEMRIC index within the 6 subgroups (P<0.01). There were no differences in cartilage thickness (combined femoral head and acetabular cartilage) between the failed and survived hips (p>0.2).

Patients with a high dGMERIC index (indicating high GAG content) may have a higher chance of successful outcomes following PAO. Current efforts are underway to develop a multi-modal predictive model to evaluate risk of failure after PAO.

Developmental dysplasia of the hip can cause pain and premature osteoarthritis. However, the risk factors and timing for disease progression in young adults are not fully defined. This study identified the incidence and risk factors for contralateral hip pain and surgery after periacetabular osteotomy (PAO) on an index dysplastic hip.

Patients followed for 2+ years after unilateral PAO were grouped by eventual contralateral pain or no-pain, based on modified Harris Hip Score, and surgery or no-surgery. Univariate analysis tested group differences in demographics, radiographic measures, and range-of-motion. Kaplan-Meier survival analysis assessed pain development and contralateral hip surgery over time. Multivariate regression identified pain and surgery risk factors. Pain and surgery predictors were further analyzed in Dysplastic, Borderline, and Non-dysplastic subcategories, and in five-degree increments of lateral center edge angle (LCEA) and acetabular inclination (AI).

184 patients were followed for 4.6±1.6 years, during which 51% (93/184) reported hip pain and 33% (60/184) underwent contralateral surgery. Kaplan-Meier analysis predicted 5-year survivorship of 49% for pain development and 66% for contralateral surgery. Painful hips exhibited more severe dysplasia than no-pain hips (LCEA 16.5º vs 20.3º, p<0.001; AI 13.2º vs 10.0º p<0.001). AI was the sole predictor of pain, with every 1° AI increase raising the risk by 11%. Surgical hips also had more severe dysplasia (LCEA 14.9º vs 20.0º, p<0.001; AI 14.7º vs 10.2º p<0.001) and were younger (21.6 vs 24.1 years, p=0.022). AI and a maximum alpha angle ≥55° predicted contralateral surgery.

5 years after index hip PAO, 51% of contralateral hips experience pain and 34% percent are expected to need surgery. More severe dysplasia, based on LCEA and AI, increases the risk of contralateral hip pain and surgery, with AI being a predictor of both outcomes. Knowing these risks can inform patient counseling and treatment planning.

Mixed Reality has the potential to improve accuracy and reduce required dissection for the performance of peri-acetabular osteotomy. The current work assesses initial proof of concept of MR guidance for PAO.

A PAO planning module, based on preoperative computed tomography (CT) imaging, allows for the planning of PAO cut planes and repositioning of the acetabular fragment. 3D files (holograms) of the cut planes and native and planned acetabulum positions are exported with the associated spatial information. The files are then displayed on mixed reality head mounted device (HoloLens2, Microsoft) following intraoperative registration using an FDA-cleared mixed reality application designed primary for hip arthroplasty (HipInsight). PAO was performed on both sides of a bone model (Pacific Research). The osteotomies and acetabular reposition were performed in accordance with the displayed holograms. Post-op CT imaging was performed for analysis. Cutting plane-accuracy was evaluated using a best-fit plane and 2D angles (°) between the planned and achieved supra (SA)- and retroacetabular (RA) osteotomy and retroacetabular and ischial osteotomies (IO) were measured.

To evaluate the accuracy of acetabular reorientation, we digitized the acetabular rim and calculated the acetabular opening plane. Absolute errors of planned and achieved operative inclination and anteversion (°) of the acetabular fragment, as well as 3D lateral-center-edge (LCE) angles were calculated.

The mean absolute difference between the planned and performed osteotomy angles was 3 ± 3°.

The mean absolute error between planned and achieved operative anteversion and inclination was 1 ± 0° and 0 ± 0° respectively. Mean absolute error between planned and achieved 3D LCE angle was 0.5 ± 0.7°.

Mixed-reality guidance for the performance of pelvic osteotomies and acetabular fragment reorientation was feasible and highly accurate. This solution may improve the current standard of care by enabling reliable and precise reproduction of the desired acetabular realignment.

Periacetabular Osteotomy (PAO) has become the most important surgical procedure for patients with hip dysplasia, offering significant pain relief and improved joint function. This study focuses on recovery after PAO, specifically the return to sports (RTS) timeline, with the objective of identifying preoperative predictors to optimize patient outcomes.

Our prospective, monocentric study from 2019 to 2023 included 698 hips from 606 patients undergoing PAO. Comprehensive preoperative data were collected, including demographic information, clinical assessments (Modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHot-12), Hip Disability and Osteoarthritis Outcome Score (HOOS), UCLA Activity Score) and psychological evaluations (Brief Symptom Inventory (BSI) and SF-36 Health Survey). Advanced logistic regression and machine learning techniques (R Core Team. (2016)) were employed to develop a predictive model.

Multivariate regression analysis revealed that several preoperative factors significantly influenced the RTS timeline. These included gender, invasiveness of the surgical approach, preoperative UCLA Score, preoperative sports activity level, mHHS, and various HOOS subscales (Sport/Recreation, Symptoms, Pain) as well as psychological factors (BSI and SF-36). The subsequent model, using a decision tree approach, showed that the combination of a UCLA score greater than 3 (p<0.001), non-female gender (p=0.003), preoperative sports frequency not less than twice per week (p<0.001), participation in high-impact sports preoperatively (p=0.008), and a BSI anxiety score less than 2 (p<0.001) had the highest likelihood of early RTS with a probability of 71.4% at three months.

Using a decision tree approach, this model provides a nuanced prediction of RTS after PAO, highlighting the synergy of physical, psychological, and lifestyle influences. By quantifying the impact of these variables, it provides clinicians with a valuable tool for predicting individual patient recovery trajectories, aiding in tailored rehabilitation planning and predicting postoperative satisfaction.

Sequelae of Legg-Calve -Perthes disease (LCPD) and treatment of developmental dysplasia of the hip (DDH) can present a coxa breva or coxa magna deformity, sometimes associated with coxa vara. This unique deformity decreases the efficiency of the abductor mechanism, causing a Trendelenburg gait and hip pain, leg length discrepancy and leads to intra- and extra-articular impingement, and eventually osteoarthritis. Several surgical techniques have been advocated to treat this kind deformity, such as great trochanter transfer, relative femoral neck lengthening. We evaluated primary results of true femoral neck-lengthening osteotomy (TFNLO) in combination with periacetabular osteotomy (PAO) for treatment of Coxa Breva through surgical hip dislocation (SHD).

Fourteen patients with Coxa Breva received true femoral neck lengthening osteotomy in combination of PAO through SHD between March 2020 and October 2023. Ten patients with minimum 1 year followed-up were retrospectively reviewed clinically and radiographically. Eight patients had Perthes disease, 2 had DDH received closed reduction and fixation during childhood. The mean age at surgery was 16 years (range, 12 to 31 years). Clinical findings, radiographic analyses including the change in horizontal femoral offset and the leg length discrepancy as well as complications were assessed.

Horizontal femoral offset improved 19.5mm(6–28mm). Limb length increase 16.8mm(11–30mm). Mean HHS increased from 80.6(66–91) to 91.8(88–96). Complication: screw broken in 1(no need operation). Asymptomatic fibrous union of the great trochanter was found in 1. No infection and joint space narrow as well as nerve palsy happened.

TFNLO combined with PAO can be effective for the treatment of patients with Coxa breva. But long term follow up is warranted.

The Bernese periacetabular osteotomy (PAO) is not indicated for growing hips as it crosses the triradiate cartilage in its posterior branch, and experimental work has shown this can induce substantial deformations, similar to posttraumatic dysplasia, which is observed after pelvis crash injuries in childhood.

Upon examination, all injuries in the 19 cases of posttraumatic dysplasia described in literature plus 16 hips of our personal collection took place before the age of 6, which is striking as pelvic injuries in children increase with age.

Based on this observation, we started to extend the PAO indication to severe dysplasias in children with open growth plate, initially aged 9 years and older. Following the positive results, it was extended further, our youngest patient being 5 years old.

We retrospectively examined radiographic outcomes of 23 hips (20 patients), aged 10.6±1.8 years [range 5.0 – 13.2], operated by us in four centers. Pre- and 3-months postoperative, and the latest FUP radiograph at growth plate closure were measured. We evaluated the acetabular index (AI), lateral center-edge (LCE), ACM-value and compared them with reference values adjusted for age. The age at triradiate cartilage closure was compared with the non-operated side.

The follow-up time was 5.4±3.7 years [0.8 - 12.7]. In 5 hips, growth plate closure was delayed by a few months. All angles significantly normalized after PAO (LCE: 14±8° → 38±11°, AI: 20±8° → 7±4°, ACM: 53±5° → 48±4°), with >80% of them severe pathological pre-PAO, none afterwards. Acetabular molding was normal. Only few complications occurred; one had signs of coxarthosis, one sciatic nerve pain, one interfering osteosynthesis material that was removed, one had an additional valgus osteotomy, and all resolved.

Based on 20 cases with follow-up until complete triradiate cartilage closure, we believe to have sufficient information to extend the PAO indication to growing hips of 9 years and older.

Dislocations have impact on quality of life, but it is difficult to quantify this impact for each patient. The Quality-of-Life Time Trade-Off assesses the percentage of a patient's remaining life that the patient would be willing to trade for perfect health [1]. This technique has been used for non-unions [2], but never proposed for dislocation.

154 patients (with 3 recurrent dislocations) undergoing revision were asked to choose between living with their associated dislocation risk or trading a portion of their life expectancy for a period of perfect health without dislocation, thus determining their Quality-of-Life score. This score may range from 0.1 (willing to trade nine years among 10) to 1.0 (unwilling to trade any years). Additionally, patients were assessed on their willingness to trade implant survival time for a reduced risk of dislocation, considering various implant options that might offer lower (but not necessary) survival time before revision than the theoretical best (for the surgeon) “standard” implant, thus determining a “Survival Implant Quality” score.

Patients diagnosed with 3 hip dislocations have a low health-related quality of life. The score of our “dislocation” cohort was average 0.77 with patients willing to trade average 23% of remaining lifespan for perfect health (range 48% to 12%). This score is below that (0.88) of illnesses type-I diabetes mellitus [3] and just higher than tibial non-union (0.68) score [2]. The mean “Survival Implant Quality” score of our recurrent dislocation cohort was 0.71 (range 0.59 to 0.78) which means that patients accept to trade average 3 years (range 2 to 4 years) among 10 theoretical years of survival of the implant.

Hip dislocation has a devastating impact that can be quantified for each patient when discussing revision and choice of implants for instability.

For references, please contact the author directly.

Dislocation is a serious complication to be avoided in total hip arthroplasty (THA) and its incidence risk increases in revision surgery. Combined anteversion (CA) of the cup and stem is a concept for appropriate implant positioning; however, the effect of functional changes in femoral rotation has not been well investigated. The aim of this study was to investigate whether functional CA, considering femoral rotation, is associated with dislocation in patients undergoing revision THA.

Seventy-three patients who underwent revision THA and had at least one year of follow-up with pre- and postoperative supine CT imaging were included. Cup and stem were placed with a target combined angle of 37.3° using Widmer's formula. Anatomical and functional CA was calculated postoperatively using the following formula: Anatomical CA: cup anteversion + 0.7 × anatomical stem anteversion; Functional CA: cup anteversion + 0.7 × (anatomical stem anteversion + femoral rotation). Patient demographics, cup and stem angles, CA and their relationship to dislocation were statistically evaluated.

Dislocation was observed in 12 patients. In these dislocated cases, there were no significant differences in cup angle, stem angle and anatomical CA compared to non-dislocated cases. However, dislocated cases showed significantly higher values of functional CA [52.7 ± 17.5° (range, 5.9–69.3) vs. 36.0 ± 12.5° (range, 8.6–68.8), p=0.009] and significant deviation from identical CA [17.3 ± 9.6° (range, 2.8–32) vs. 7.5 ± 7.1° (range, 0.1–28.7), p=0.010].

Functional CA considering femoral rotation was associated with dislocation in revision THA patients. This finding suggests that consideration of femoral rotation may be necessary for implant positioning in revision THA.

Dislocation after total hip replacement (THR) is a devastating complication. Risk factors include patient and surgical factors. Mitigation of this complication has proven partially effective. This study investigated a new innovating technique to decrease this problem using rare earth magnets.

Computer simulations with design and magnetic finite element analysis software were used to analyze and quantitate the forces around hip implants with embedded magnets into the components during hip range of motion. N52 Neodymium-Iron-Boron rare earth magnets were sized to fit within the existing acetabular shells and the taper of a hip system. Additionally, magnets placed within the existing screw holes were studied. A 50mm titanium acetabular shell and a 36mm ceramic liner utilizing a taper sleeve adapter were modeled which allowed for the use of a 12mm × 5mm magnet placed in the center hole, an 18mm × 15mm magnet within the femoral head, and 10mm × 5mm magnets in the screw holes.

Biomechanical testing was also performed using in-vitro bone and implant models to determine retention forces through a range of hip motion.

The novel system incorporating magnets generated retentive forces between the acetabular cup and femoral head of between 10 to 20 N through a range of hip motion. Retentive forces were stronger at the extreme position hip range of motion when additional magnets were placed in the acetabular screw holes. Greater retentive forces can be obtained with specially designed femoral head bores and acetabular shells specifically designed to incorporate larger magnets. Mechanical testing validated the loads obtained and demonstrated the feasibility of the magnet system to provide joint stability and prevent dislocations.

Rare earth magnets provide exceptional attractive strength and can be used to impart stability and prevent dislocation in THR without the complications and limitations of conventional methods.

Hip precautions following total hip arthroplasty (THA) limits flexion, adduction and internal rotation, yet these precautions cause unnecessary psychological stress. This study aims to assess bony and implant impingement using virtual models from actual patient's bony morphology and spinopelvic parameters to deduce whether hip precautions are necessary with precise implant positioning in the Asian population.

Individualized sitting and standing sacral slope data of robotic THAs performed at two tertiary referral centers in Hong Kong was inputted into the simulation system based on patients’ pre-operative sitting and standing lumbar spine X-rays. Three-dimensional dynamic models were reconstructed using the Stryker Mako THA 4.0 software to assess bony and implant impingement both anteriorly and posteriorly, with default cup placement at 40° inclination and 20° anteversion. Femoral anteversion followed individual patient's native version. A 36mm hip ball was chosen for all cups equal or above 48mm and 32mm for those below. Anterior impingement was assessed by hip flexion and posterior impingement was assessed by hip extension.

113 patients were included. At neutral rotation and adduction, no patients had anterior implant impingement at hip flexion of 100°. 1.7% had impingement at 110°, 3.5% had impingement at 120°, 9.7% had impingement at 130°. With 20° of internal rotation and adduction, 0.8% had anterior implant impingement at hip flexion of 90°, 7.1% had impingement at 100° and 18.5% had impingement at 110°. With the hip externally rotated by 20°, 0.8% of patients had posterior implant impingement, and 8.8% bony impingement at 0° extension.

With enabling technology allowing accurate component positioning, hip precautions without limiting forward flexion in neutral position is safe given precise implant positioning and adequate osteophyte removal. Patients should only be cautioned about combined internal rotation, adduction with flexion.

This study evaluates patient reported outcome measurement information system (PROMIS) scores after total hip arthroplasty (THA) and total ankle arthroplasty (TAA) in matched cohorts, while simultaneously evaluating implant survivorship and 90-day hospital utilization. It is hypothesized that while both procedures would yield similar PROMIS score improvements, THA would demonstrate superior mid-term implant survivorship.

Primary THA and TAA patients from 2015–2022 with minimum one-year follow-up were retrospectively reviewed. After applying exclusion criteria, 2,092 THAs and 478 TAAs were included for analysis. Demographics, pre- and post-operative patient reported outcome measures (PROMs), revision surgeries, ED visits, and re-admissions were collected. THA and TAA patients were then propensity score matched at 2:1 ratio for age, sex, race, BMI, ASA, and comorbidities, resulting in a final cohort of 844 THAs and 455 TAAs for comparison.

There were similar pre-operative PROMIS Pain Interference (PI) scores between THA and TAA, with both showing improvement at six weeks. However, THA patients exhibited lower PI scores at one year (53.0 versus 54.0; p=0.009). Pre-operative PROMIS Physical Function (PF) was worse in THA patients but showed greater improvement compared to TAA patients at both six weeks (p<0.001) and one year (p<0.001). Pre-operative PROMIS depression scores were similar and improved similarly in both groups. Joint-specific PROMs (HOOS for THA and FAAM for TAA) improved in both cohorts. THA demonstrated superior survivorship free of all-cause revision at five years compared to TAA (95% versus 77%; p<0.0001).

Patients undergoing THA or TAA experienced significant improvements in their general and joint-specific PROMs post-operatively. However, patients undergoing THA demonstrated higher PROMIS PI and PF scores at one-year when compared to TAA, as well as improved survivorship. Generic PRO instruments enable comparison of medical treatments in different anatomic sites to the patients overall health.

The results of total hip arthroplasty (THA) revisions to correct leg length discrepancy (LLD) are not clear, with only two former limited series (< 25 patients). Therefore, we conducted a retrospective study of THA revisions for LLD to determine: 1) the change in LLD, 2) the function outcomes and whether obtaining equal leg lengths influenced function, 3) the complication and survival rates.

This multicenter study included 57 patients: 42 THA revisions for limb shortening and 15 revisions for limb lengthening. LLD was measured on conventional radiographs and EOS. The Oxford-12 and FJS outcome scores were collected and the number of patients achieving the Oxford-12 MCID.

The revisions were carried out a mean of 2.8 years after the index THA. The median LLD decreased from 7.5 mm (IQR: [5;12]) to 1 mm (IQR: [0.5;2.5]) at follow-up (p=0.0002). Overall, 55 of 57 patients (96%) had < 5 mm LLD at follow-up and 12 patients (21%) had equal leg lengths. The complication rate was 25%: 12 mechanical complications (8 periprosthetic femoral fractures, 2 stem loosening and 1 cup loosening, 1 dislocation) and 1 periprosthetic infection. The patient satisfaction was high with a median FJS of 79.2/100 and 77% of patients reached the Oxford-12 MCID. Lengthening procedures had significantly worst function than shortening (38% vs 91% of patients achieving the Oxford-12 MCID (p=0.0004)). Survivorship was 85% (95% CI: 77.9 – 92.5) at 2 years and 77% (95% CI: 66.3 – 87.1) at 4.6 years when using re-revision for any reason as the endpoint.

When LLD after THA does not respond to conservative management, revision THA should be considered. Although revision THA for LLD improved medium-term functional outcomes with a high patient satisfaction rate, especially for shortening procedures, the complication rate was high, particularly related to periprosthetic femoral fracture.

The painful hip without obvious clinical or radiographic signs of complications is a well-known scenario for surgeons. The clinical tools we have access to currently lack a dynamic test for detecting early signs of motion between implant and bone.

A new software, Sectra IMA, has a potential to facilitate diagnosis of early implant loosening by analysis of paired CT exams. In clinical practise the two scans are acquired by endpoint of a possible motion, “a provocation CT”, for example maximal external and internal rotation in a CT hip examination. 20 years of research by Olivecrona and Weidenhielm is the scientific background for the technique. Early results are presented by Sandberg et al 2022.

To further validate and create clinical evidence more extensive clinical studies is needed. A proposal for a multicentric, global clinical study will be presented for further discussion.

A new technique for diagnosis of acetabular cup loosening using computed tomography: preliminary experience in 10 patients. Henrik Olivecrona, Lotta Olivecrona, Lars Weidenhielm, Marilyn E Noz, Jocelyn Kardos, Gerald Q Maguire Jr, Michael P Zeleznik, Peter Aspelin. Acta Orthop. 2008 Jun;79(3):346-53. doi: 10.1080/17453670710015247.

Inducible displacement CT increases the diagnostic accuracy of aseptic loosening in primary total hip arthroplasty. Sandberg O, Carlsson S, Harbom E, Cappelen V, Tholén S, Olivecrona H, Wretenberg P. Acta Orthop. 2022 Oct 31;93:831-836. doi: 10.2340/17453674.2022.5240.PMID: 36314542

Early micromotion of hip implants measured with radiostereometric analysis (RSA) is a predictor for late aseptic loosening. Computed Tomography Radiostereometric Analysis (CT-RSA) can be used to determine implant micro-movements using low-dose CT scans. CT-RSA enables a non-invasive measurement of implants. We evaluated the precision of CT-RSA in measuring early stem migration. Standard marker-based RSA was used as reference. We hypothesised that CT-RSA can be used as an alternative to RSA in assessing implant micromotions.

We included 31 patients undergoing Total Hip Arthroplasty (THA). Distal femoral stem migration at 1 year was measured with both RSA and CT-RSA. Comparison of the two methods was performed with paired-analysis and Bland-Altman plots. Furthermore, the inter- and intraobserver reliability of the CT-RSA method was evaluated.

No statistical difference was found between RSA and CTMA measurements. The Bland-Altman plots showed good agreement between marker-based RSA and CT-RSA. The intra- and interobserver reliability of the CT-RSA method was found to be excellent (≥0.992).

CT-RSA is comparable to marker-based RSA in measuring distal femoral stem migration. CTMA can be used as an alternative method to detect early implant migration.

When treating periprosthetic femur fractures (PPFFs) around total hip arthroplasty (THA)], determining implant fixation status preoperatively is important, since this guides treatment regarding ORIF versus revision. The purpose of this study was to determine the accuracy of preoperative implant fixation status determination utilizing plain films and CT scans.

Twenty-four patients who underwent surgery for Vancouver B type PPFF were included in the study. Two joint surgeons and two traumatologists reviewed plain films alone and made a judgment on fixation status. They then reviewed CT scans and fixation status was reassessed. Concordance and discordance were recorded. Interobserver reliability was assessed using Kendall's W and intraobserver reliability was assessed using Cohen's Kappa. Ultimately, the “correct” response was determined by intraoperative findings, as we routinely test the component intraoperatively.

Fifteen implants were found to be well-fixed (63%) and 9 were loose. Plain radiographs alone predicted correct fixation status in 53% of cases. When adding the CT data, the correct prediction only improved to 55%. Interestingly, concordance between plain radiographs and CT was noted in 82%. In concordant cases, the fixation status was found to be correct in 55% of cases. Of the 18% of cases with discordance, plain films were correct in 43% of cases, and the CT was correct in 57%. Interobserver reliability demonstrated poor agreement on plain films and moderate agreement on CT. Intraobserver reliability demonstrated moderate agreement on both plain films and CT.

The ability to determine fixation status for proximal PPFFs around uncemented femoral components remains challenging. The addition of routine CT scanning did not significantly improve accuracy. We recommend careful intraoperative testing of femoral component fixation with surgical dislocation if necessary, and the surgeon should be prepared to revise or fix the fracture based on those findings.

No single test has demonstrated absolute accuracy in the diagnosis of periprosthetic joint infection (PJI). Leukocyte esterase (LE) is a synovial marker that has proven utility in the diagnosis of PJI. The purpose of this prospective study was to (1) identify the optimal cutoff for the use of LE in the diagnosis of PJI and (2) determine whether performance of the LE strip test varied by infecting organism.

This prospective study enrolled 1,015 patients undergoing hip or knee revision arthroplasty at a single institution from 2009 to September 2021. PJI was defined using a modified version of 2018 International Consensus Meeting (ICM) criteria that excluded LE when calculating the ICM score. Receiver operating characteristic curves were used to assess the utility of the LE strip test in the diagnosis of PJI.

973 patients were included in the analyses. 246 (25.4%) were classified as ICM-positive and 727 (74.6%) were classified as ICM-negative. An LE cutoff of “1+” (AUC 0.819, sensitivity 73.2%, specificity 90.6%) had superior accuracy to an LE cutoff of “2+” (AUC 0.713, sensitivity 43.9%, specificity 98.8%) in the overall diagnosis of PJI (p<0.001). When stratifying by organism type, an LE cutoff of “1+” had the best diagnostic utility for PJI caused by methicillin resistant Staphylococcus aureus (AUC 0.888, sensitivity 87.0%, n=23) followed by Streptococcus spp. (AUC 0.882, sensitivity 85.7%, n=28), coagulase negative Staphylococci (AUC 0.836, sensitivity 76.6%, n=47), methicillin sensitive Staphylococcus aureus (AUC 0.806, sensitivity 70.6%, n=34), culture negative (AUC 0.793, sensitivity 67.9%, n=56), and gram negative rods (AUC 0.763, sensitivity 61.9%, n=21).

To our knowledge, this is the largest study evaluating the utility of the LE strip test in the diagnosis of PJI. Based on our findings, it appears that a “1+” cutoff has higher diagnostic utility than a cutoff of “2+”.

Debate continues about the best treatment for patients over 65 years with non-displaced subcapital hip fractures: internal fixation (IF) or hemiarthroplasty (HA). Surgical aggression, mortality, complications and recovery of walking ability after 1year have been compared between both treatments.

Match-paired comparison of 2 retrospective cohorts. 220 patients with IF vs 220 receiving a cemented bipolar HA. Matching by age (82.6±7.16 years (65–99)), sex (74.5% women), year of intervention (2013–2021) and ASA scale (24.2% ASA II, 55.8% III, 20.0% IV).

Age (p=0.172), sex (p=0.912), year of intervention (p=0.638) and ASA scale (p=0.726) showed no differences.

Surgical aggression smaller in IF: Surgical time (p< 0,00001), haemoglobin/haematocrit loss (p <0,00001), need for transfusion (p<0,00008), in-hospital stay (p<0,00001).

Mortality: higher in-hospital for hemiarthroplasties (12 deaths (5.5%) vs 1 (0.5%) (p=0.004) (RR=12, 1.5–91.5)). But no significant differences in 1-month (13 hemiarthroplasties, 6%, vs 9 osteosynthesis, 4.1%) and 1-year mortality (33 hemiarthroplasties, 15%, vs 35, 16%).

Medical complications: no differences in urinary/respiratory infections, heart failure, ictus, myocardial infarction, digestive bleeding, pressure sores or pulmonary embolus (p=0.055).

Surgical complications: no significant differences. HA: 6 intraoperative (2,7%) and 5 postoperative periprosthetic fractures (2,3%), 5 infections (2,3%), 10 dislocations (4,5%), 3 neurovascular injuries. IF: 10 acute fixation failures (4,5%), 2 infections (0,9%), 9 non-unions (4,1%), 16 ischemic necrosis (7,3%).

Functional results: no significant differences; 12 patients in each group (5,5%) never walked again (p=1), 110 HA (50%) and 100 IF (45.5%) suffered worsening of previous walking ability (p=0.575), 98 HA (44%) and 108 IF patients (49%) returned to pre-fracture walking ability (p=0.339).

Fixation with cannulated screws may be a better option for non-displaced femoral neck fractures because recovery of walking ability and complications are similar, while surgical aggression and in-hospital mortality are lower.

We aimed to examine outcomes between displaced femoral neck fracture (FNF) patients managed with total hip arthroplasty (THA) or hemi-arthroplasty (HA) via the anterolateral vs. posterior approach.

We used data from the HEALTH trial (1,441 patients aged ≥50 with displaced FNFs randomized to THA vs. HA). We calculated each patient's propensity to undergo arthroplasty via the posterior approach, and matched them to 1 control (anterolateral approach) based on age (±5 years), and propensity score. We used Chi-Square/Fisher-Exact tests to compare dichotomous outcomes, and repeated measures ANOVA to examine differences in patient-reported outcomes (via the WOMAC subscores) from baseline to one-year postoperative. We used logistic regression to identify independent predictors of reoperation for instability in the posterior group.

We identified 1,306 patients for this sub-analysis, 876 (67.1%) who received arthroplasty via an anterolateral approach, and 430 (32.9%) a posterior approach. The unadjusted rate of reoperation was significantly higher in the posterior group (10.7% vs. 7.1%).

Following propensity score matching, we retained 790 patients (395 per group), with no between-group differences in patient, fracture, or implant characteristics. The matched cohort had a higher rate of comorbidities, and were less likely to be employed vs. the unmatched cohort. The rate of treatment for dislocation remained higher in the posterior group (6.1% vs. 2.0%) following matching.

Repeated measures ANOVA revealed significantly better WOMAC pain, stiffness, function, and total scores in the posterior group. Between-group differences at 12-months were: pain - 0.59 (0.03–1.15); stiffness - 0.62 (0.35–0.87); function - 2.99 (0.12–5.86); total - 3.90 (0.24–7.56). We identified THA (vs. HA, odds ratio 2.05 [1.05–4.01]) as the only independent predictor of treatment for dislocation in the posterior group.

Our analyses revealed that compromised patients with displaced FNFs who undergo arthroplasty via the posterior approach may report better symptoms at one-year vs. the anterolateral approach, despite a higher odds of reoperation for instability.

After a hip fracture, infections are common, but signs of infection resemble those of systemic inflammatory response to trauma and surgery, and conventional infection markers lack specificity. Plasma-calprotectin, a novel marker of neutrophil activation, has shown potential as an infection marker in ER and ICU settings.

To investigate if plasma-calprotectin is superior compared to conventional infection biomarkers after hip fracture.

Prospective cohort study of hip fracture patients admitted to our department. Calprotectin, procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) count were measured in blood plasma upon admission and on day 3 post-surgery. Patients with infection (pneumonia, UTI, sepsis, SSI, other soft tissue infections) pre- or post-surgery were compared to a control group without infection within 30 days.

Statistics: Wilcoxon rank-sum test, medians with interquartile range, and area under the curve (AUC) with 95% confidence intervals.

Pilot study comprises calprotectin obtained at least once for 60 patients at admission and 48 on day 3. Mean age 84 years (SD 8.4), 65% women.

9/60 patients (23%) were admitted with infections. They had higher levels of CRP (median 111 [73-149]) and PCT (0.35 [0.18–0.86]) compared to the control group (29 [16-64], p=0.037; 0.10 [0.07–0.17], p=0.007). Calprotectin (2.67 vs 2.51) and WBC (12.2 vs 9.3) did not differ significantly. AUC was highest for PCT (0.79 [CI 0.60–0.97]), followed by CRP (0.71 [0.46–0.96]), WBC (0.60 [0.35–0.84]), and calprotectin (0.58, [0.33–0.83]).

Day 3, 6/48 (13%) had infections, without significant differences between groups in any marker. The median levels were: calprotectin 3.5 vs 3.1, CRP 172 vs 104, WBC 12 vs 9, PCT 0.16 vs 0.17. Calprotectin had highest AUC 0.68 (0.41–0.93, n.s.). AUC for WBC was 0.67 (0.31–1.00), CRP 0.66 (0.38–0.94), PCT 0.56 (0.29–0.82).

Preliminary data show no significant associations with postoperative infection for any of the studied biomarkers. However, plasma-calprotectin might perform slightly better compared to conventional markers.

There is some evidence to suggest that outcomes of THA in patients with minimal radiographic osteoarthritis may not be associated with predictable outcomes. The aim of this study was to:

A retrospective review of 107 hips (102 patients, 90F:12M, median age 40.6, IQR 35.1–45.8 years, range 18–73) were included for analysis. Plain radiographs were evaluated using the Tonnis grading scale of hip OA. Outcome measures were all-cause revision; iHOT12; EQ-5D; Oxford Hip Score; UCLA Activity Scale; and whether THA had resulted in the patient's hip pain and function being Better/Same/Worse.

The median Oxford Hip Score was 33.3 (IQR 13.9, range 13–48), and 36/107 (33.6%) hips achieved an OHS≥42. There was no association between primary hip diagnosis and post-operative PROMs. A total of 91 of the 102 patients (89.2%, 93 hips) reported that their hip pain and function was Better than prior to THA and would have the surgery again, 7 patients (6.8%, 10 hips) felt the Same, and 4 patients (3.9%, 4 hips) felt Worse and would not have the surgery again.

Younger patients undergoing total hip arthroplasty with no or minimal radiographic osteoarthritis had lower postoperative Oxford Hip Scores than the general population; though most felt symptomatically better and knowing what they know now, would have surgery again. Those with chronic pain syndrome or hypermobility were likely to benefit less. Those with subchondral cysts or joint space narrowing on CT imaging were more likely to achieve higher functional scores and satisfaction.

An intra-articular steroid injection can be a useful diagnostic tool in patients presenting with debilitating hip pain and radiographically mild osteoarthritis. The clinical and patient reported outcomes associated with patients who have radiographically mild osteoarthritis and undergo total hip arthroplasty (THA) remain poorly studied.

Patients undergoing primary, elective THA at a single academic medical center by a fellowship-trained adult reconstruction surgeon between 2017–2023 were identified. Only those patients who underwent an intra-articular corticosteroid injection into the operative hip within one year of surgery were included. Patients were divided into two cohorts based on the severity of their osteoarthritis as determined by preoperative radiographs; those with Kellgren-Lawrence (KL) grade I-II arthritis were classified as “mild” whereas those with KL grade III-IV arthritis were classified as “severe”. Clinical and patient reported outcomes at final follow-up were compared between cohorts.

The final cohorts included 25 and 224 patients with radiographically mild and severe osteoarthritis, respectively. There were no baseline differences in age, gender or time between intra-articular corticosteroid injection and THA between cohorts. There were no significant differences in the preoperative or postoperative HOOS JR values between patients with mild or severe arthritis (all p>0.05). There were no significant differences in the change in HOOS JR scores from the preoperative to final follow-up timepoints between cohorts. There were no significant differences in the percentage of patients who achieved the minimal clinically important difference (MCID) on the HOOS JR questionnaire between cohorts.

Patients with radiographically mild osteoarthritis who feel relief of their hip pain following an intra-articular corticosteroid injection report similar preoperative debility and demonstrate similar improvements in patient reported outcome scores following THA compared to patients with radiographically severe osteoarthritis.

Most hip replacements are performed in an in-patient setting; however, there has been a shift in recent years in Canada towards doing more on an outpatient basis. In 2021–2022, 15.6% of hip replacements were performed as day surgeries compared to 0.7% in 2018–2019. This analysis will assess patient reported outcome measures of patients who had inpatient versus outpatient hip replacement surgery between 2018 and 2021.

We analysed a retrospective sample of 4917 adult patients who had an elective primary unilateral hip replacement. Preoperative and three-month postoperative PROMs were completed - the Oxford Hip Score, EQD5L and patient satisfaction with the outcome were recorded. Patients who had an outpatient procedure were matched 1:1 with patients who are admitted to hospital for surgery based on age, sex and pre-COVID versus the COVID (March 15, 2020 as the start). Preoperative PROMs and Charlson Comorbidity Index were collected. T-tests and chi-square tests were used to assess the differences.

The inpatient group on average was older, female and had a lower preoperative PROMs score and more comorbidities than the outpatient group. With cohort matching the sample consisted of 1244 patients. The inpatient and outpatient groups have similar Oxford scores, postoperative EQ-5D-5L scores and the proportion satisfied with their surgical results. The Oxford postoperative score was slightly higher in the outpatient group compared to the inpatient group; however, this is not clinically significant.

We observed that outpatient protocols have no difference in patient satisfaction, self-reported functional outcomes and self-reported health-related quality of life three months after a hip replacement. Day surgery protocols represented potential solution to the challenges caused by the expected increase in demand for hip replacements. Our results demonstrated that patients do well clinically with day surgery procedures and there does not appear to be any detrimental effect on PROMs.

Recently, some smart media devices including portable accelerometers have been used to measure objective physical activity (OPA) after total hip arthroplasty (THA). The aim of this study was to longitudinally assess OPA changes in patients who underwent THA using a compact triaxial accelerometer and to investigate the impact of this recovery process on patient-reported outcomes.

This prospective cohort study involved 163 consecutive patients who had unilateral osteoarthritis of the hip and were followed up for 12 months after THA. There were 132 women and 31 men with average age of 66 years. OPA was measured using a compact triaxial accelerometer preoperatively and at 1, 3, 6, and 12 months postoperatively. This study investigated the recovery process of OPA in four patient groups classified by the median of age and preoperative activity levels (younger and higher activity (YH), younger and lower activity (YL), older and higher activity (OH), and older and lower activity (OL)), and examined its impact on patient-reported outcomes, including forgotten joint score-12 (FJS-12).

The target period for regaining preoperative activity levels was approximately 3 months for patients with lower preoperative activity, and about 6 months for those with higher preoperative activity. The OPA at 12 months postoperatively was higher in the patients with higher preoperative activity levels than in those with lower preoperative activity levels. In patients with higher preoperative activity levels, FJS-12 scores significantly increased between 6 and 12 months postoperatively (p=0.018). FJS-12 at 12 months postoperatively was best in YH (81.7±18.9), followed by YL (73.5±22.9), OH (73.2±17.4), and OL (66.3±21.8).

Differences in the recovery process of postoperative activity levels impacted the duration required for improvement in FJS-12 scores. These results can serve as indicators for setting activity goals in patients undergoing THA.

It is not unusual for patients prior to their total hip arthroplasty (THA) to indicate that their symptoms worsen with certain meteorological conditions. However, the prevalence and evolution of weather-related pain (WRP) following THA remain poorly understood. The aim of this study was to investigate the prevalence of WRP both before and after primary THA, to assess the impact of THA on pre-existing WRP, and to identify potential risk factors associated with WRP.

An in-person survey was conducted on 442 primary THAs, in 327 consecutive patients at the time of their postoperative follow-up. Each patient was assessed using a questionnaire specifically designed to address weather-related joint pain before and after their THA. The clinical evaluation included patient-reported outcome scores (PROMS).

Preoperatively, 17% of THA hips experienced WRP, with 71% achieving complete resolution postoperatively (p < 0.001). In patients with WRP in multiple joints and their hip, the THA failed to alleviate the WRP in 31% of the cases. In addition, 8% of the THA patients developed de-novo WRP after surgery. Although the overall prevalence of WRP in hips post-THA was 12%, the prevalence was 29% in hips with WRP preoperatively and 31% in the hips of patients with WRP in multiple joints as well as their hip. WRP in other joints, the initial diagnosis, body mass index (BMI), and age were correlated with WRP following THA.

WRP is not uncommon prior to and after THA. Although THA can effectively alleviate WRP in specific patient populations, it does not universally eliminate preoperative WRP or prevent the emergence of new WRP after surgery.

The growth of life expectancy during the last decades has led to an increment in age-related conditions such as hip arthritis and fractures. On the other hand, these elderly patients will present a higher incidence of mental diseases which, in some studies, have been associated with inferior results.

This study aims to evaluate the differences in early complication rates between patients with cognitive impairment compared with those without this condition following total hip replacement for osteoarthritis or fracture in the context of contemporary perioperative care protocols.

We conducted a retrospective cohort study where cognitively-impaired patients who required primary hip arthroplasty were compared to a propensity-score matched cohort of patients without cognitive alterations. Early major complications were measured and analyzed in order to determine significant differences.

Screening and matching. 1196 patients were identified during the study period. After screening for inclusion and exclusion criteria and matching, two cohorts comprising 65 patients each were compared. After performing the propensity-score match, no significant differences were found in covariates between the two groups.

Outcomes. The occurrence of delirium was more frequent in patients with cognitive deficit (27.5%) than in the control group (9%), p<0.001. No significant differences were found among groups regarding myocardial infarction, venous thromboembolism, blood transfusion requirement, 30-day readmission, in-hospital death, 90-days death, dislocation or surgical site infection. The composite outcome of any adverse event did not exhibit a significant difference either.

To our knowledge, this is the first study which demonstrates similar outcomes between patients with cognitive impairment and those without these alterations. Our results might indicate that contemporary protocols and implants are bridging the traditional gap between these two populations. These findings support the use of total hip arthroplasty in patients with mental alterations when indicated, especially in those institutions with strict perioperative protocols.

The purpose of this study was to assess the variability in implant position between sides in patients who underwent staged, bilateral THA and whether variation from one side to the other affected patient-reported outcomes.

A retrospective review was conducted on 207 patients who underwent staged, bilateral THA by the same surgeon from 2017–2022. Leg length, acetabular height, cup version, and coronal and sagittal stem angles were assessed radiographically and compared to the contralateral THA. Surgical approach and technology utilization were further assessed for their impact on variability. Linear regression was used to model the relationship between side-to-side variability and patient-reported outcome measures (PROMS).

Between sides, mean radiographic leg length varied by 4.6mm (0.0–21.2), acetabular height varied by 3.3mm (0.0–13.7), anteversion varied by 8.2° (0.0 to 28.7), coronal stem alignment varied by 1.1° (0.0 to 6.9), and sagittal angulation varied by 2.3° (0.0 to 10.5). The anterior approach resulted in more variability in stem angle position in both the coronal (1.3° vs. 1.0°, p=0.036) and sagittal planes (2.8° vs. 2.0° p=0.012) compared to the posterior approach. The posterior approach generally led to more anteversion than the anterior approach. Use of robotics or navigation for acetabular positioning did not increase side-to-side variability in cup-related position or leg length. Despite considerable side-to-side variability, Hip dysfunction and osteoarthritis outcome scores (HOOS JR) were not affected by higher levels of position inconsistency.

Staged, bilateral THA results in considerable variability in component position between sides. The anterior approach leads to more side-to-side variability in sagittal stem angle and cup anteversion than the posterior approach. Navigation and robotics do not improve the consistency of component position in bilateral THA. Variation in implant position was not associated with differences in PROMs, suggesting that despite variability, patients can tolerate these differences between sides.

While obesity is associated with an increased risk of complications after total hip arthroplasty (THA) the relationship between body mass index (BMI) and the risk of early postoperative complications has not been fully characterized. This study sought to describe the relationship between BMI and the risk of early postoperative complications, including periprosthetic joint infection (PJI), composite surgical, and composite medical complications.

Primary, elective THAs performed from 2016–2021 were identified using the Premier Healthcare Database (PHD). The study's primary outcome was the diagnosis of PJI within 90 days of THA. Using BMI as a continuous variable, logistic regression was used to develop restricted cubic splines (RCSs) to determine the impact of BMI on PJI risk. Bootstrap simulation was used to identify an inflection point in the final RCS model. The same technique was used to characterize the effects of BMI on composite medical and surgical complications.

We found that PJI risk increased exponentially beyond a BMI cutpoint of 37.4 kg/m². Relative to the cutpoint, patients with a BMI of 40 or 50 kg/m² were at a 1.22- and 2.55-fold increased risk of developing PJI, respectively. Surgical complications increased at a BMI of 32 kg/m² and medical complications increased at a BMI of 39 kg/m². Relative to these cutpoints, patients with a BMI of 50 kg/m² were at a 1.36- and 2.07-fold increased risk of developing medical and surgical complications, respectively.

The results of this study indicate a non-linear relationship between patient BMI and early postoperative risk of PJI, composite medical complications, and composite surgical complications following THA. The identified cutpoints with associated odds ratios can serve as tools to help risk-stratify and counsel patients seeking primary THA.

Obesity is a known risk factor for developing osteoarthritis and is also associated with an increased risk of developing complications post total hip replacement (THR). This study investigated the association between obesity and the risk of undergoing THR in Australia.

From July 2017 to June 2018 a National Health Survey was conducted by the Australian Bureau of Statistics to collect height and weight data on a representative sample of patients across urban and rural areas across the country. This study examined a cohort of patients undergoing primary THR utilising data from the Australian Orthopaedic Association National Joint Replacement Registry from the same time period. Obesity classes were determined according to WHO criteria.

Body mass index (BMI) for patients undergoing THR were obtained and the distribution of THR patients by BMI category was compared to the general population, in age and sex sub-groups.

Generalised linear models assuming a binomial distribution and a log link were used to generate relative risks. Data from underweight categories, and age categories 34 years and younger, were excluded from further analyses because of small numbers.

Data from the health survey showed there were 35.6% of persons overweight and 31.3% obese. During the same period, 32,495 primary THR were performed for osteoarthritis in Australia on patients who had a BMI recorded. Of these patients 37.1% were overweight and 41.7% were obese. Compared to the general population, there was a higher incidence of Class I, II, and III obesity in patients undergoing THR in both sexes aged 35 to 74 years. Class III obese females and males aged 55–64 years were 2.9 and 1.7 times more likely to undergo HR, respectively (p<0.001). Class III obese females and males underwent THR on average 5.7 and 7.0 years younger than their normal weight counterparts, respectively.

Obese Australians are at increased risk of undergoing THR, and at a younger age. A national approach to address the prevalence of obesity, and possible prevention strategies, is needed.

The purpose of our study is to examine the outcome of patients undergoing outpatient total hip arthroplasty with a BMI >35.

Case-control matching on age, gender (46% female;54%male), and ASA (mean 2.8) with 51 outpatients BMI≥35 kg/m² (mean of 40 (35–55)), mean age of 61 (38–78) matched to 51 outpatients BMI<35 kg/m² (mean of 27 (17–34)) mean age 61 (33–78). Subsequently 47 inpatients BMI≥35 kg/m² (mean of 40 (35–55)) mean age 62 (34–77) were matched outpatients BMI≥35 kg/m². For each cohort, adverse events, readmission in 90 days, reoperations were recorded.

Rate of adverse events was significantly higher in BMI ≥35: 15.69% verus 1.96% (p=0.039) with 5 reoperations in the BMI≥35 cohort vs 0 in the BMI<35 kg/m² (p= 0.063). Readmissions did not differ between groups (p=0.125). No significant difference for all studied outcomes between the outpatient and inpatients cohorts with BMI≥35 kg/m². The most complications requiring surgery/medical intervention (3B) were in the inpatient cohort of patients >35. The prevalence of Diabetes and Obstructive Sleep apnea was 21.6% and 29.4% for BMI>35 compared to 9.8% and 11.8%, for BMI <35, respectively.

Severely obese patients have an overall higher rate of adverse events and reoperations however it should not be used a sole variable for deciding if the patient should be admitted or not.

We report the impact of implementing a new short-stay hip and knee arthroplasty pathway in a National Health Service (NHS) hospital. This was enacted due to existing concerns with a long length of stay (LOS) and reduced elective operating capacity each winter due to emergency bed pressures. The overnight introduction of this pathway was aimed to reduce LOS, alleviate bed pressures, minimise readmission rates and generate financial savings, all combining to facilitate full elective activity during the winter.

We conducted a prospective study at a regional tertiary arthroplasty centre. The new pathway was introduced across the service overnight. It includes rigorous preoperative optimisation, specific anaesthetic protocols and uniform changes in surgical practice to allow a focus on early mobilization and discharge on the day of surgery where possible.

Data collection spanned 17 months, including the initial six months post implementation of the short-stay pathway. LOS data was collected for the full period and data was compared pre- and post-implementation of the new pathway. Patient satisfaction and 30-day readmission data were also collected.

There was an immediate and significant decrease in median LOS from 4 days pre-implementation to 1 day post-implementation. Patient satisfaction was high, and the 30-day readmission rate was unchanged (5.95%), with no readmissions directly related to decreased inpatient stay. Financial analyses revealed substantial cost savings due to reduced LOS and the elimination of routine post-operative blood tests, estimated at over £1.6m per year. Elective activity over winter was significantly higher (79%) than in the same time period in the previous year.

An acute introduction of a carefully planned and coordinated short-stay hip and knee pathway is safe, cost-effective and popular with patients, but also contributes to increased efficiency in the delivery of elective healthcare in the context of increasing demand and financial constraints in the NHS.