Cementless Total Hip Replacement Research Articles

Quasi-static mechanical evaluation of canine cementless total hip replacement broaches: effect of tooth design on broach and stem insertion

BackgroundBiomedtrix BFX® cementless total hip replacement (THR) requires the use of femoral broaches to prepare a press-fit envelope within the femur for subsequent stem insertion. Current broaches contain teeth that crush and remove cancellous bone; however, they are not particularly well-suited for broaching sclerotic (corticalized) cancellous bone. In this study, three tooth designs [Control, TG1 (additional V-grooves), TG2 (diamond tooth pattern)] were evaluated with a quasi-static testing protocol and polyurethane test blocks simulating normal and sclerotic bone. To mimic clinical broaching, a series of five sequential broach insertions were used to determine cumulative broaching energy (J) and peak loads during broach insertion. To determine the effect of broach tooth design on THR stem insertion, a BFX® stem was inserted into prepared test blocks and insertion and subsidence energy and peak loads were determined.ResultsBroach tooth design led to significant differences in broaching energy and peak broaching loads in test blocks of both densities. In low density test blocks, TG1 required the lowest cumulative broaching energy (10.76 ±0.29 J), followed by Control (12.18 ±1.20 J) and TG2 (16.66 ±0.78 J) broaches. In high density test blocks, TG1 required the lowest cumulative broaching energy (32.60 ±2.54 J) as compared to Control (33.25 ±2.16 J) and TG2 (59.97 ±3.07 J). During stem insertion and subsidence testing, stem insertion energy for high density test blocks prepared with Control broaches was 14.53 ± 0.81 J, which was significantly lower than blocks prepared with TG1 (22.53 ± 1.04 J) or TG2 (19.38 ± 3.00 J) broaches. For stem subsidence testing in high density blocks, TG1 prepared blocks required the highest amount of energy to undergo subsidence (14.49 ± 0.49 J), which was significantly greater than test blocks prepared with Control (11.09 ±0.09 J) or TG2 (12.57 ± 0.81 J) broaches.ConclusionsThe additional V-grooves in TG1 broaches demonstrated improved broaching performance while also generating press-fit envelopes that were more resistant to stem insertion and subsidence. TG1 broaches may prove useful in the clinical setting; however additional studies that more closely simulate clinical broach impaction are necessary prior to making widespread changes to THR broaches.

Analysis on association between sagittal stem alignment and early functional and radiological outcome following primary cementless total hip replacement.

Accurate reconstruction of hip anatomy and biomechanics is mandatory for achieving good clinical outcomes following total hip replacement (THR). Optimal stem alignment is essential to avoid impingement or loosening. This study aimed to evaluate sagittal stem position following cementless THR and its relationship with patient's functional outcome and post-operative radiological parameters. We performed analytical observational study with cross-sectional design on 71 hips (67 patients, ranged 18-85years old) that underwent primary cementless THR in two orthopedic centers in Jakarta, Indonesia. All hips were operated through either anterolateral or posterior approach using either extended/full-coating wedge-tapered stem or proximal-coated wedge-tapered stem. Clinical outcomes were evaluated at follow-up time using mHHS questionnaire, VAS level of thigh pain, and hip ROM. Stem sagittal alignment and other radiological parameters, including combined anteversion and offset, were measured from conventional radiograph. There were no significant differences on mHHS score, VAS level on thigh pain, and ROM between stem alignment groups. Post-operative anteversion and offset of the implant were not affected by the stem sagittal position. All influencing factors have significant effect on sagittal stem alignment. Linear regression test on femur morphology showed 0.69° increase in stem posterior tilt for every 1° increase in the anterior bowing (coeff. = 0.502). Stem tilting in sagittal plane did not affect patient's functional outcome or post-operative radiological parameters. In addition, for every degree of increased anterior femoral bowing, 0.69° increase in posterior stem tilting can be expected.

A case report of a cementless total hip replacement performed in a pelvic limb amputee after a failed surgical reduction of a traumatic coxo-femoral luxation with a toggle rod.

Coxo-femoral luxation is the most common luxation seen in dogs after road traffic accidents. There are multiple surgical techniques to repair the luxation. These range from a capsular reconstruction to a total hip replacement. This case report describes a total hip replacement to repair a failed toggle rod repair of a coxo-femoral luxation in a Greyhound pelvic limb amputee. The dog returned to normal activity as a household pet three months post-surgery and at the last follow-up consultation at 12 months post-surgery the dog was able to maintain an acceptable activity level as an amputee with no radiographic signs of complications.

Results of Total Hip Replacement Surgery Using Short-Stem Spiron Prosthesis in Vietnamese Adults.

Total hip arthroplasty with traditional stem joints, although bringing many benefits to patients indicated for hip replacement, faces many difficulties in reoperations in young patients due to the limited lifespan of the artificial joint. Recently, the short-stem joint was introduced to help overcome this problem. This study aims to evaluate the results of short-stem implants for primary total hip arthroplasty in Vietnamese adults. The study design is retrospective longitudinal. The study subjects were 91 patients with aseptic necrosis of the femoral head who underwent short-shaft cementless total hip replacement surgery from February 2012 to December 2018. Outcomes that were assessed included implant survivorship, Harris hip scores, thigh pain, periprosthetic fracture, subsidence, proximal stress shielding, the prevalence of stem malalignment, and inappropriate implant sizing. Our research group has 119 hips of 91 patients (28 patients had hip replacements on both sides), with the average follow-up time of 67.1 months. Seven cases of early joint loosening required replacing the traditional stem. The survival rate is 94.1%. The average Harris hip score 24 months after surgery was statistically significantly higher than before (92.00 ± 4.47 and 45.56 ± 3.22, respectively, p < 0.001). The average leg length discrepancy between the two limbs before surgery was 9.5 ±mm and 24 months after surgery was 3.4 ± 2.9 mm. There were 12 cases (10.1%) of partial bone loss around the femoral stem; 12 cases of joint displacement of more than 2 mm, accounting for 10.1%; and 1 case of acetabular fracture, accounting for 0.8%. The Spiron short stem has certain advantages suitable for young patients, restoring the hip anatomy and significantly improving postoperative hip function. However, this is a complex technique that needs to be performed by experienced surgeons who have practiced for a long time. We encourage using the short-stem implant during primary total hip arthroplasty in Vietnamese adult patients.

Total hip replacement among sickle cell patients in alow-income country-Yemen.

Sickle cell patients presented with progressive hip pain and limitation of daily activities, as evidenced by low preoperative hip scores and failed conservative therapy. Management of femoral head avascular necrosis (AVN) using total hip replacement (THR) in sickle cell disease (SCD) is widespread in developed countries, but it is still in its initiation stage in developing countries. The outcome of using cementless THR among SCD patients is still unknown with lack of published studies from regional countries. This study aimed to evaluate the outcome of using cementless primary THR among patients with sickle cell disease with end-stage hip avascular necrosis in Yemen. Thirty cementless primary total hip arthroplasty (THA) were performed for AVN of the femoral head in 27 sickle cell patients, at Al.-Thawra Modern General Hospital-Sana'a, Yemen, from January 2018 to December 2022. The mean age of the patients was 27 ± fiveyears (ranged 18-37years) with a male to female ratio was 3:1. Steinberg staging for hip AVN was stage IV, one patient (3%); stage VI, thirteen patients (45%); and stage V, sixteen patients (51%). THR was on right side 14 (52%), left side 10 (37%), and bilateral 3 (11%). The implant used was ceramic on polyethylene acetabular liner. All patients showed improvement in Harris hip score from preoperative mean hip score was 25 ± 8 points to postoperative mean hip score was 88 ± 6 points at the last follow-up. Mean of the length of stay in hospital was 12.7 ± eightdays (ranged from 4 to 32days); the mean operating time was 107 ± 23min. Three cases had superficial wound infection; four patients had five intraoperative fractures; two cases had pulmonary complications; one case had abdominal crisis. All patients had postoperative leg length discrepancy less than 2cm. None had deep infection, nerve injury, wound hematoma, aseptic loosing, dislocation, DVT, heterotopic ossification, or death. THR in SCD has a good outcome using cementless THA with a low rate of complication in Yemen, a developing country.

Minimum 20-year follow-up of a press-fit acetabular cup in cementless total hip replacement in young patients.

We aimed to determine the minimum 20-year survival rates of a cementless press-fit cup in young patients. This is a retrospective, single-center, multi-surgeon cohort study investigating the minimum 20-year clinical and radiological outcome of the first 121 consecutive total hip replacements (THRs) using a cementless, press-fit cup (Allofit, Zimmer, Warsaw, IN, USA) performed between 1999 and 2001. 28-mm metal-on-metal (MoM) and ceramic-on-conventionally not highly crosslinked polyethylene (CoP) bearings were used in 71% and 28%, respectively. Median patient age at surgery was 52 (range 21-60) years. Kaplan-Meier survival analysis was conducted for different endpoints. The 22-year survival rate for the endpoint aseptic cup or inlay revision was 94% (95% confidence interval [CI] 87-96) and 99% (CI 94-100) for aseptic cup loosening. 20 patients (21 THRs; 17%) had died and 5 (5 THRs; 4%) were lost to follow-up. No THR showed evidence of radiographic cup loosening. Osteolysis was observed in 40% of THRs with MoM and 77% with CoP bearings. 88% of THRs with CoP bearings showed significant polyethylene wear. The investigated cementless press-fit cup, which is still in clinical use today, showed excellent long-term survival rates in patients under the age of 60 years at surgery. However, osteolysis due to polyethylene and metal wear was frequently observed and is a matter of concern in the third decade after surgery.

Cementless total hip replacement for hip dysplasia: anatomical hip center is associated with better patient-reported functional outcome

Background Total hip arthroplasty in patients with dysplastic hips is a challenging procedure. The main goal of surgery is to achieve anatomical center of rotation to improve the abductor function, patient satisfaction, and implant survival. The aim of this study was to report the mid-term functional results using the Oxford hip score (OHS) after cementless total hip replacement (THR). Patients and methods This was a retrospective analysis of the prospectively collected data of patients who had a THR done at our institution with hip dysplasia. Between September 2011 and December 2019, a total of 23 consecutive patients (26 hips) with Crowe II–IV developmental dysplasia were treated with primary cementless THR. The mean age for patients included were 34.1 ± 15.2 years. Females were more than males. The left side was operated more than the right side, and there were three bilateral cases. The mean preoperative OHS was 21 ± 6.6 points. Results All patients were followed up for a mean of 3.4 ± 2.6 years (range, 1–11 years). None of the cases were lost to follow-up. The mean OHS improved significantly from 21.2 ± 6.6 points (range, 8–38) preoperatively to 40.9 ± 4.8 points (range, 28–48) in the final OHS (Z=4.45, P<0.001). Regarding the final OHS, both Crowe types II and III were better than Crowe type IV, and the difference was statistically significant. The functional leg length discrepancy improved from a median of 3 (0–7) cm preoperatively to 0 (0–3) cm postoperatively (Z=4.3, P<0.0001). All cases that required shortening were Crowe IV dysplasia (five cases). A total of 22 (88%) hips were reconstructed within 2 cm of the other hip. Conclusion Restoration of anatomic center of rotation as close as possible was associated with better functional outcome. Cementless fixation was possible in all cases.

COMPARISON OF RATES OF ASEPTIC LOOSENING IN HIGH OFFSET VERSUS STANDARD OFFSET CEMENTLESS FEMORAL STEMS

Increasing femoral offset in total hip replacement (THR) has several benefits including improved hip abductor strength and enhanced range of motion. Biomechanical studies have suggested that this may negatively impact on stem stability. However, it is unclear whether this has a clinical impact. Using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), the aim of this study was to determine the impact of stem offset and stem size for the three most common cementless THR prostheses revised for aseptic loosening.The study period was September 1999 to December 2020. The study population included all primary procedures for osteoarthritis with a cementless THR using the Corail, Quadra-H and Polarstem. Procedures were divided into small and large stem sizes and by standard and high stem offset for each stem system. Hazard ratios (HR) from Cox proportional hazards models, adjusting for age and gender, were performed to compare revision for aseptic loosening for offset and stem size for each of the three femoral stems.There were 55,194 Corail stems, 13,642 Quadra-H stem, and 13,736 Polarstem prostheses included in this study. For the Corail stem, offset had an impact only when small stems were used (sizes 8-11). Revision for aseptic loosening was increased for the high offset stem (HR=1.90;95% CI 1.53–2.37;p&lt;0.001).There was also a higher revision risk for aseptic loosening for high offset small size Quadra-H stems (sizes 0-3). Similar to the Corail stem, offset did not impact on the revision risk for larger stems (Corail sizes 12-20, Quadra-H sizes 4-7). The Polarstem did not show any difference in aseptic loosening revision risk when high and standard offset stems were compared, and this was irrespective of stem size.High offset may be associated with increased revision for aseptic loosening, but this is both stem size and prosthesis specific.

Oral enzyme combination with bromelain, trypsin and the flavonoid rutoside reduces systemic inflammation and pain when used pre- and post-operatively in elective total hip replacement: a randomized exploratory placebo-controlled trial.

Early mobilization after total hip replacement (THR) is key for fast recovery but is often limited by pain. Oral enzyme combinations (OECs) have demonstrated anti-inflammatory and pain-relieving effects. This prospective, randomized, double-blind, placebo-controlled exploratory trial evaluated the effects of pre- and post-operative use of OEC (90 mg bromelain, 48 mg trypsin, 100 mg rutoside) following elective THR, on post-operative recovery. Candidates for primary elective cementless THR owing to osteoarthritis were eligible for participation [age ⩾50 years, body mass index 25-35 kg/m2, C-reactive protein (CRP) ⩽6 mg/L]. Following randomization to OEC or placebo, intervention started pre-operatively and continued onwards until day 42. Main outcomes included post-operative CRP levels (days 1-7), self-reported hip pain at rest (by 0-10 cm visual analogue scale on post-operative days 1-42), post-operative analgesic use [by cumulative analgesic consumption score (CACS) days 7-42], tolerability and adverse events. Patients (N = 34) were recruited from a tertiary orthopaedic hospital in the Czech Republic, of whom 33 completed the study (OEC/placebo: n = 15/18). Baseline characteristics across the groups were comparable. Compared with placebo, the OEC group had numerically lower CRP levels on post-operative days 1-7, including peak level [mean (standard deviation) OEC versus placebo: 81.4 (28.3) versus 106.7 (63.3) mg/L], which translated into a significant 32% lower CRP area under the curve (p = 0.034). The OEC group reported significantly less pain during post-operative days 1-7 versus placebo (analysis of variance treatment × visit [F(4) = 3.989]; p = 0.005). Analgesic use was numerically reduced as assessed through an accumulated CACS. No deleterious effects on haemorheological parameters were observed in either group. Pre- and post-operative use of OEC significantly reduced CRP levels and patient self-reported pain. OEC may be an efficacious and safe treatment option to facilitate post-operative recovery following THR. EudraCT number 2016-003078-41.

Total hip arthroplasty and Paget's disease: case report and literature review.

Paget's disease (PDB) is a chronic osteopathy more common in male, Caucasic, European population, after the age of 50 years, that can lead to bone deformities. A challenging surgical solution for affected hip with severe hip osteoarthritis is total hip replacement (THA). We describe a case of THA in a 71-year-old patient with PDB and we present a literature review. In particular we find out that more studies comparing cementless THA with cemented one are necessary, in order to understand if one implant is better than the other.

Combined administration of tranexamic acid and vitamin K proved perioperative blood loss reduction with cementless total hip replacement

Combined administration of tranexamic acid and vitamin K proved perioperative blood loss reduction with cementless total hip replacement

Greater trochanter morphology and association with patient demographics, surgical factors, and post-operative stem position: a retrospective assessment of 150 cementless THRs in 135 dogs

BackgroundTotal hip replacement (THR) in the gold standard surgical treatment for the canine hip. While it has been shown that greater trochanter morphology affects post-operative cementless stem position in humans, trochanter morphology and the effect on cementless stem position has not been extensively evaluated in dogs. The objective of this study was to classify greater trochanter morphology and identify potential associations between trochanter morphology and patient demographics, femoral canal geometry, surgical time, technique modifications, and post-operative stem position in client-owned dogs undergoing cementless THR.ResultsIn this retrospective study, medical records and radiographs of 135 dogs undergoing 150 cementless total hip replacements from 2013 to 2020 were included. Trochanters were classified in the frontal plane using an ordinal grading system adapted from human THR. A Grade I trochanter denoted a trochanter positioned lateral to the periosteal surface of the lateral femoral cortex, whereas a Grade IV trochanter denoted a trochanter positioned medial to the anatomic axis of the femur. Associations between trochanter grade and other variables were examined using ANOVA, Kruskall-Wallis, or chi-squared tests. Significance was assumed at P ≤ .05.Trochanters were classified as follows: Grade I (44/150, 29.3%), Grade II (56/150, 37.4%), Grade III (44/150, 29.3%), Grade IV (6/150, 4.0%). Grade IV trochanters had lower anatomic lateral distal femoral angle (aLDFA; 91.0 ± 6.2°), angle of inclination (117.7 ± 10.5°), and canal flare index (1.53 ± 0.27). When compared to all groups, Grade IV trochanters were associated with longer surgical times (Grade IV: 227.0 ± 34.2 min; all grades: 183.2 ± 32.9 min) and technique modifications (Grade IV: 83.3%; all grades: 18%). Grade I trochanters had stems placed in valgus (− 1.8 ± 2.33°), whereas Grade II (0.52 ± 2.36°), III (0.77 ± 2.58°), and IV (0.67 ± 2.73°) trochanters exhibited varus stems. Depth of stem insertion was greater (11.2 ± 4.2 mm) for Grade IV trochanters.ConclusionsTrochanter grade was associated with post-operative stem alignment and translation in the frontal plane. Grade IV trochanters were associated with altered femoral geometry, increased surgical time, technique modifications, and stem insertion depth. Pre-operative greater trochanter classification may prove useful in identifying cases requiring prolonged surgical times or technique modifications.

Combined administration of tranexamic acid and vitamin K proved perioperative blood loss reduction with cementless total hip replacement: a prospective randomized controlled study

Introduction Blood loss during total joint replacement has serious implications on patients affecting their ability to immediately start the postoperative enhanced recovery program. Tranexamic acid (TA) is well known for its ability to reduce blood loss during arthroplasty. Vitamin K has an important physiological role in the clotting cascade, but its action is delayed and dose sensitive. Study settings and design A prospective comparative study conducted in Benha University Hospital. Patients and methods In all, 150 patients were randomly divided into three groups, each included 50 patients. Group A received both TA and vitamin K1, group B received only vitamin K1, and group C received only TA. Perioperative blood parameters tested included hemoglobin level, hematocrit percentage, platelet count, prothrombin time, partial thromboplastin time, and fibrinogen level. Intraoperative and postoperative blood losses and the amount of blood transfusion were reported. A surgeon satisfaction score was created to assess the degree of intraoperative bleeding. Results The mean perioperative differences in blood parameters and amount of blood loss were evaluated with the post-hoc test. Group A showed a statistically significant less changes in blood parameters and less blood loss than the other groups, and group B showed less postoperative blood losses. Conclusion Combined administration of TA and vitamin K with cementless total hip replacement proved efficient in reducing intraoperative and postoperative blood losses and the need for blood transfusion. This was reflected on the patient’s ability to start the enhanced recovery program immediately, reduced the duration of postoperative hospital stay, and the overall cost of operation.

Comparison of osteotomy level with three different canine total hip replacement systems.

Numerous cementless total hip replacement (THR) systems are available for application in dogs and one of the potential differences among these systems is the technique for performing a femoral osteotomy and the amount of bone preserved in the calcar region. However, no quantitative comparison of osteotomy level has been performed for canine THRs to date. To develop and validate a method for quantifying the level of the osteotomy at its most distomedial aspect in conjunction with canine THR and to compare osteotomy level between multiple different THRs. Immediate post-operative cranial-caudal or caudal-cranial radiographs of 33 dogs treated with 17 Helica and 17 BFX THR were assessed and osteotomy level was quantified using a novel radiographic assessment by 3 independent observers. Correlation among observers was quantified using a Spearman rank order correlation. Osteotomy location was subsequently quantified for an additional 10 Zurich THRs. The osteotomy level for each THR was subsequently compared between Helica, BFX, and Zurich THRs using one-way non-parametric Mann-Whitney rank sum tests and significance set at p < 0.05. R-values assessing correlation between observers were 0.87, 0.72, and 0.60. Osteotomy location was significantly more proximal in conjunction with the Helica (0.75 ± 0.22) versus the BFX (0.97 ± 0.13; p < 0.001) and Zurich (1.1 ± 0.15; p < 0.001) femoral prostheses. Osteotomy location was also significantly more proximal with the BFX prosthesis in comparison to the Zurich THR (p < 0.05). The strong correlations among three different observers indicate that the technique for measuring the location of the distomedial aspect of the osteotomy was acceptably precise. The osteotomies made in conjunction with the short-stemmed Helica implants were significantly more proximal than those made with both of the long-stemmed (BFX and Zurich) femoral prostheses. The distomedial aspect of the osteotomy with the BFX system was significantly more proximal than that with the Zurich THR, indicating that between these two long-stemmed systems the osteotomy level is unique.

Case factors for selection of femoral component type in canine hip arthroplasty using a modular system.

To describe a femoral stem selection process based on case features in dogs treated with total hip replacement (THR) by an expert surgeon, compare complications between implant types, and develop an algorithm for stem type selection. Retrospective study. 128 dogs, 135 THR. Data collected included breed, age, weight, canal flare index (CFI), and implant type: cementless (BFX), cementless with a collared stem (BFX-C), hybrid (cementless acetabular component with cemented stem), and cemented (CFX). Of the 135 THRs, 69 BFX, 47 hybrid, and 18 BFX-C were performed. Dogs receiving hybrid (mean 5.5 years) were older than those receiving BFX (2.5 years, p < .0001) and BFX-C implants (2.5 years, p=.0014). The mean weights of dogs with hybrid, BFX, and BFX-C implants were 40.0, 31.0, and 35.3kg, respectively, with dogs receiving hybrid heavier than those receiving BFX (p < .0001). Mean CFI for hybrid (1.52) was lower than for BFX (1.79, p < .0001) and BFX-C (1.76, p=.0021). Total complication rate was 14.0% with catastrophic complications in 1.5% and no association between implant type and risk of complications (p=.36). Femur fractures occurred in 2.9% of all cases and 1.1% of cementless THR cases. Dogs receiving hybrid THR were older with lower CFI than dogs receiving BFX and BFX-C and heavier than dogs receiving BFX. There was no difference in complications between groups. Catastrophic complications and femur fractures occurred less frequently compared to recent studies of BFX THR. Careful preoperative assessment and implant selection can reduce complications of canine THR.

Initial results in restoration of some anatomical dimensions in standard cementless total hip replacement

Objective: To give initial results in the restoration of some important anatomical parameters (femoral neck angle, distance from the center of the crest to the femoral axis (offset), and limb deviation) in the standard cementless total hip replacement in the treatment of aseptic necrosis of the femoral head. Subject and method: In studies in the period from 2/2021 to 6/2021, the authors used the Medi-CAD software integrated on the computer to determine the femoral neck angle, the distance from the center of the crest to the femoral axis (offset), the limb deviation of 24 hip joints was surveyed on 20 patients at the time preoperative and postoperative with standard Zimmer hip joints. The method used in this study is a cross-sectional, prospective study. Result: The results show that the mean postoperative femoral neck angle was 131.1 ± 3.2º while the preoperative size was 129.8 ± 3.4º. The average postoperative offset size was 35.6 ± 4.8mm and higher than before surgery was 32.5 ± 5.4mm. Postoperative limb deviation was 3.2 ± 2.7mm and lower than preoperative was 12.3 ± 4.5mm, the difference was insignificant statistically. Conclusion: Research results show that the closer the femoral neck angle and the offset is to the original value, the better the limb balance.

Outcome of canine cementless collared stem total hip replacement with proximal femoral periprosthetic cerclage application: 184 consecutive cases.

To report outcomes of cementless collared stem total hip replacement (THR) with proximal femoral periprosthetic cerclage application in dogs. Retrospective case series. Client-owned dogs (n = 150) with THR (n = 184). Serial postoperative radiographs and medical records of dogs that underwent consecutive index cementless THR, with a single full cerclage wire placed distal to the femoral neck osteotomy line and proximal to the lesser trochanter, were reviewed for intraoperative and postoperative complications. No proximal femoral fractures occurred. No complications associated with the use of the cerclage wire were encountered. A fissure (n=1) or fractures (n=2) occurred near the tip of the femoral stem in three cases postoperatively. All three cases required plate and screw fixation. All dogs returned to subjectively normal function at home and all owners were satisfied with the outcome. A single full cerclage wire may minimize the risk of a proximal femur fracture following cementless collared stem total hip replacement in dogs. No complications were encountered with the cerclage wire. Application of a cerclage wire is a simple and economically feasible procedure that requires minimal additional instrumentation, takes little time, and may decrease the risk of proximal femur fractures after cementless press-fit THR.

Cementless Ceramic-on-Ceramic Total Hip Replacement in Children and Adolescents.

Background: total hip replacement (THR) is a rare surgical option in children and adolescents with disabling hip diseases. The aim of this study is to report results from a retrospective cohort of patients aged 18 years or less who underwent cementless Ceramic-on-Ceramic (CoC) THR at a single institution, investigating clinical and radiographic outcomes, survival rates, and reasons for revision of the implants. Materials and methods: we queried the Registry of Prosthetic Orthopedic Implants (RIPO) to identify all children and adolescents undergoing THR between 2000 and 2019 at a single Institution. Inclusion criteria were patients undergoing cementless CoC THR, aged less than 18 years at surgery, followed for at least 2 years. Sixty-eight patients (74 hips) matched all the inclusion criteria and were enrolled in the study. We assessed the clinical and radiographic outcomes, the rate of complications, the survival rate, and reasons for revision of the implants. Results: The mean follow-up was 6.6 ± 4.4 years (range 2–20). The most frequent reason for THR was post-traumatic or chemotherapy-induced avascular necrosis (38%). The overall survival rate of the cohort was 97.6% (95% CI: 84.9–99.7%) at 5 years of follow-up, 94.4% (95% CI: 79.8–98.6%) at 10 years and 15 years of follow-up. Two THR in two patients (2.7%) required revision. With the numbers available, Cox regression analysis could not detect any significant interaction between preoperative or intraoperative variables and implant survivorship (p-value 0.242 to 0.989).” The average HOOS was 85 ± 14.3 (range 30.6–100). Overall, 23 patients (48%) reported excellent HOOS scores (>90 points), 21 patients (44%) reported acceptable HOOS scores (60–90 points) while 4 patients (8%) reported poor outcomes (<60 points). Twenty-one patients (43%) were regularly involved into moderate- to high-intensity sport activities (UCLA ≥ 6). Conclusions: Cementless CoC THR is a successful procedure in children and teenagers, having demonstrated high implant survivorship and low rates of complications and failure. A meticulous preoperative planning and implant selection is mandatory, to avoid implant malposition, which is the main reason of failure and revision in these cases. Further studies are needed to assess the impact of the THR on the psychosocial wellbeing of teenagers, as well as risks and benefits and cost-effectiveness in comparison to the hip preserving surgical procedures.

Evaluation of a novel method to calculate cementless femoral stem level on craniocaudal projection radiographs.

To assess the accuracy of a proportion-corrected radiographic cementless femoral stem level calculation in a cadaver model. Cadaveric study. Twelve cadaveric canine femurs. Cementless femoral stems were implanted in 12 cadaver femurs at three stem levels. Craniocaudal projection radiographs of the implanted femurs were obtained at 0°, 10°, 20°, 30°, and 45° angulations in the sagittal plane (relative to the radiographic plate) and at 0°, 15°, and 30° internal and external axial rotation. A proportional calculation including actual stem length, radiographically measured stem length, and radiographically measured stem level relative to the greater trochanter (uncorrected stem level) was solved to yield a corrected stem level. The errors of the stem level measurements were compared. With 0° or 15° of internal rotation, the true stem level differed by more than 0.5 mm from corrected stem level in 2 of 30 tested femoral positions. It differed from the uncorrected stem level in 10 of 30 positions. With 15° and 30° external rotation or 30° internal rotation, the corrected stem level was not more accurate than the uncorrected stem level for any femoral position. Use of a proportion correction minimized variability in the stem-level measurements due to sagittal angulation (up to 30°) of the femur at 0° or 15° of internal rotation. A proportion correction can improve the accuracy of femoral stem-level assessment on craniocaudal projection radiographs, which may aid in the detection of subsidence after cementless total hip replacement.

Mid-term results of total hip arthroplasty with subtrochanteric Z-osteotomy in Crowe type 3-4 developmental hip dysplasia

Background/aim Total hip arthroplasty (THA) is technically more difficult and has higher complication rates in patients with Crowe type 3–4 developmental dysplasia of the hip (DDH). Due to the difficulties and different treatment options, there is still no consensus on the optimal treatment. We aimed to evaluate the mid-term results of our patients who had undergone subtrochanteric femoral shortening Z-osteotomy.Materials and methods This study included 37 hips of 29 patients with the diagnosis of Crowe 3-4 DDH between June 2010 and December 2016 and who underwent femoral shortening Z-osteotomy with cementless total hip arthroplasty. Acetabular component was determined according to the patient’s age and functional capacity and all patients were operated with a posterior approach. Functional results, postoperative complications, Harris and visual analogue scale (VAS) scores were evaluated. Results The average Harris hip score was 41.3 ± 3.1 preoperatively and 84.7 ± 4.3 postoperatively (p < 0.05). The mean preoperative hip pain score on the VAS was 7.9 (range: 6–9) and this was significantly lower at the last follow-up (mean: 3.4; range: 2–4) (p < 0.05). The final mean limb-length discrepancy was 1.3 cm. The average amount of femoral shortening was 3.2 cm. Regarding complications, 3 (10.3%) patients had dislocations. These patients underwent closed reduction. Sciatic palsy developed in 1 (3.4%) patient. The patient was reoperated on for sciatic nerve dissection in the early period.Conclusion Subtrochanteric shortening Z-osteotomy combined with cementless total hip replacement can be considered an effective and successful method in selected patients with Crowe 3-4 coxarthrosis.