Project description:BackgroundIn total hip arthroplasty (THA), component position is critical to avoid instability and improve longevity. Appropriate combined femoral and acetabular component anteversion is important for improved THA stability and increased impingement-free range of motion. In direct anterior THA (DA-THA), concern has been expressed regarding the accuracy of femoral component positioning. This study seeks to quantify acetabular, femoral, and combined component orientation relative to the accepted "safe zones" in patients who have undergone DA-THA.MethodsTwenty-nine patients who had THA performed via direct anterior approach had postoperative computerized tomography scans done to assess femoral anteversion. Stem rotational alignment was measured relative to the transepicondylar axis (TEA) and the posterior condylar axis (PCA) of the femur at the knee. Acetabular abduction and version were recorded on anteroposterior pelvis radiographs.ResultsThe mean stem anteversion was 17.5° (standard deviation = 10.8°) from the TEA and 21.7° (standard deviation = 11.3°) from the PCA. Ten of 30 cups were appropriately anteverted; however, all the cups had appropriate abduction. Combined version when using the TEA resulted in 79% (23/29) of patients within the "safe zone" of 25°-50°. Pearson correlation coefficients were high for both stem anteversion from the TEA (R = 0.96) and PCA (R = 0.98); however, interobserver reliability for combined component anteversion was greater for the TEA (kappa, 0.83 vs 0.65).ConclusionsCombined anteversion within the "safe zone" was achieved 79% of the time with DA-THA. Interestingly, most of the "excessive" combined anteversion appears to be related to increased anteversion of the acetabular component with only 10 patients within the acetabular cup "safe zone" of 5°-25°.
Project description:Nerve palsy following total hip arthroplasty (THA) can have a serious effect on a patient`s functional prognosis and on cost-effectiveness, and it is the leading cause of THA-associated medical litigation. However, only a few studies focus on femoral nerve palsy (FNP) following THA with the direct anterior approach (DAA). Moreover, several studies have reported that THA with DAA may result in higher complication rates, particularly during the so-called 'learning-curve period' for the surgeon. This study aimed to identify the incidence of FNP following primary THA with DAA, to determine presumed etiologies through a retrospective investigation of FNP clinical courses following primary THA with DAA and to identify any relationship between the occurrence of FNP following primary THA with DAA and the surgeon's experience of DAA. Since August 2007, DAA for primary THA was introduced in our institution. All 273 consecutive primary THAs with DAA (42 bilateral and 189 unilateral cases) between August 2007 and February 2014 were included in this study. All patients' charts and radiographs were reviewed to identify cases with palsy and to retrieve related factors. In this study, FNP was defined as weakness of the quadriceps femoris (manual muscle test <3) with or without sensory disturbance over the anteromedial aspect of the thigh. The incidence of FNP following primary THA with DAA was 1.1% (3/273 joints). In all 3 cases, the motor deficit recovered completely within a year. Suspected causes of the palsy in the 3 cases were believed to be improper positioning of the anterior acetabular retractor, excessive leg lengthening, or unknown etiology. There was no significant relationship between palsy and surgeon's experience of DAA. In THA with DAA for patients requiring major leg lengthening, the likelihood of FNP must be considered. To prevent FNP, the anterior acetabular retractor must be placed properly.
Project description:BackgroundLimited literature exists concerning the femoral cement mantle quality that can be achieved through an anterior approach in total hip arthroplasty (THA). We radiologically evaluated the quality and thickness of the femoral cement mantle in patients undergoing THA utilizing the direct anterior approach (DAA).MethodsImmediate postoperative anteroposterior and lateral radiographs of 116 consecutive patients who underwent hybrid or fully cemented THA using the DAA and cemented Quadra-C stem (Medacta, International, SA, Switzerland) were assessed by 2 arthroplasty surgeons blinded to the study. Surgical indications were hip osteoarthritis or subcapital hip fracture. The cement mantle and stem alignment were evaluated using the Barrack classification and Khalily methods, respectively. After calibration of radiographs, the thinnest part of the cement mantle per Gruen zone was recorded. Parameters were compared between obese and nonobese patients.ResultsAgreement between raters was substantial for the cement quality in anteroposterior (k = 0.707, P ≤ .001) and moderate for lateral radiographs (k = 0.574, P ≤ 001). The cement mantle was graded A in 39.25%, B in 53.0%, and C in 7.75% of anteroposterior radiographs and similarly for lateral radiographs (40.1% A, 51.75% B, 9.5% C). 93% of stems had neutral alignment. The mean thinnest cement mantle (P = .237) and incidence of inadequate cement mantle (<2 mm) per zone (P = .431) were comparable between Gruen zones. The cement mantle quality (P = .174) and inadequacy (P > .05) and stem alignment (P = .652) were comparable between obese and nonobese patients.ConclusionsDAA enables correct implantation and effective cementation of straight femoral stems. A high-quality cement mantle can be achieved using DAA even in obese patients.
Project description:ObjectiveTotal hip arthroplasty (THA) involves postoperative risks, such as thigh pain, periprosthetic fractures, and stress yielding. Short, anatomical, metaphyseal-fitting, cementless femoral stems were developed to reduce these postoperative risks. This study aimed to examine the "MiniMAX" prosthesis, which is a new generation, short, anatomical femoral stem made by Medacta.MethodsPatients underwent a low-dose computed tomography scan. Femoral anteversion was measured. We assessed the position and anteversion of the femoral component and compared them with the unoperated side. We also assessed the patients' satisfaction and functional levels at 6 months postsurgery using the Harris Hip Score (HHS) and the Oxford Hip Score (OHS).ResultsNineteen individuals were recruited in this study. We found no significant difference in femoral anteversion between the operated hip and the native hip. Using the HHS and OHS questionnaires, we found clinical improvement in the 6-month postoperative scores compared with the preoperative scores.DiscussionThe new-generation, short, anatomical femoral stem made by Medacta is successful in reproducing natural femoral anteversion, while also improving patients' functioning and lifestyle. Future large-scale, prospective comparison trials are required to further investigate this topic.
Project description:BackgroundThe direct lateral (DL) approach to total hip arthroplasty is more commonly used than the newer direct anterior (DA) approach. Both approaches use collared or collarless femoral stems. We sought to assess implant stability of stem designs implanted with the DL approach and compare outcomes from this cohort with those of a previously reported cohort of patients who underwent arthroplasty with a DA approach. We also sought to determine if early recovery influences differences in migration.MethodsPatients underwent total hip arthroplasty using the DL or the DA approach and were randomized to receive either a collared or collarless, cementless femoral stem. On the day of surgery and at 6 follow-up visits through to 1 year, patients underwent supine radiostereometric imaging to track implant migration. At follow-up visits, patients performed an instrumented walking test to assess their functional ability and logged an average daily step count to assess their activity levels. We assessed whether patient function and activity were correlated with migration.ResultsStem design did not have a significant effect on migration for the DL group (p = 0.894). Compared with the DA group, the DL group migrated significantly less for both collared (p = 0.031) and collarless (p = 0.002) stems. Migration was not correlated with function or activity at any time point (p > 0.05).ConclusionMost implant migration occurred from the day of surgery to 2 weeks after the operation and stabilized thereafter, suggesting adequate fixation and a low risk for aseptic loosening in both patient groups.
Project description:BackgroundSurgical approach is known as a risk factor that influences cup malposition while performing total hip arthroplasty (THA). However, no study has been conducted comparing cup positioning between the supine direct anterior (DA) and supine direct lateral (DL) THA approaches.Questions/purposes(1) Is there a difference in acetabular cup positioning between supine DA and supine DL THA approaches? (2) Are there differences in complications based on acetabular cup positioning between the two approaches?MethodsFrom 2012 to 2014, 186 patients who underwent primary THAs using DA approach were matched with 186 patients using DL approach by body mass index, age, and gender. Cup anteversion and abduction angles were measured from standing anteroposterior pelvis radiographs by two blinded observers. The Lewinnek safe zone was used as the standard for cup positioning. Cup anteversion, abduction angles, and complications were recorded and compared.ResultsCup anteversion was on average 3° higher in the DA approach compared to the DL approach. The abduction angle for the DA approach was equivalent to the DL approach both averaging 46° to 47°. There were more DA hips outside of the safe zone (10%) for anteversion than DL (3%) hips. There were no differences in complications between DA and DL approaches.ConclusionThere is a tendency to antevert the acetabular cup when performing THAs using the DA approach, and one must be mindful of this when implanting the acetabular component.
Project description:Subtrochanteric osteotomy of the femur (STO) is a valuable corrective procedure in hip surgeries. However, STO in traditional posterolateral approach usually encounters complications such as postoperative dislocation, bone non-union, and prosthesis failure. Some relevant pathologies and mechanisms have been identified, but there is sparse evidence for verification. The aim of this video in orthopaedic technique is to test our hypothesis of STO in direct anterior approach to total hip arthroplasty in a complicated hip surgery, and to further illustrate the rationality, reproducibility, and superiority of STO in this minimally invasive and enhanced-recovery approach by presenting a standardized and systemic protocol, as well as operational pearls and pitfalls.
Project description:Although the anterior approach for total hip arthroplasty has gained increasing utilization, some studies have suggested a higher risk of femoral complications, as well as difficulty with femoral exposure. Techniques of soft tissue releases have been described to offer better femoral exposure, and to help mitigate complications. The purpose of the study is to describe an algorithmic soft tissue femoral release in direct anterior approach total hip arthroplasty and to assess the clinical outcomes of patients upon which this algorithm of femoral soft tissue releases was utilized. Clinical outcomes with the Harris Hip Score, reoperation rates, component survivorship, and complications were analyzed.
Project description:Background: Although total hip arthroplasty (THA) performed through the direct anterior (DA) approach is frequently marketed as superior to other approaches, there are concerns about increased risks of intraoperative and early postoperative femoral fracture. Purpose: We sought to assess patient-specific and radiographic risk factors for intraoperative and early postoperative (90-day) periprosthetic femoral fracture (PPFx) following DA approach THA. Methods: We retrospectively reviewed 1107 consecutive, primary, non-cemented DA THAs, performed between April 2009 and January 2015, for intraoperative and early postoperative PPFx. Patients lost to follow-up before 90 days (63), cemented or hybrid THA (52), or early femoral failure for another indication (3) were excluded, yielding 989 hips for analysis. Demographic variables and patient comorbidities were analyzed as risk factors for PPFx. Continuous variables were initially compared with 1-way analysis of variance (ANOVA) and categorical variables with chi-square test. A demographic matched-paired radiographic analysis was performed for femoral stem canal fill and compared using univariate logistic regression. Results: The incidence of perioperative PPFx was 2.02%, including 10 intraoperative and 10 early postoperative fractures. Sustaining a postoperative PPFx was associated with being 70 years old or older with a body mass index (BMI) of less than 25, or with having either osteoporosis or Parkinson disease. Radiographs demonstrated that intraoperative PPFx was associated with stems that filled greater proximally rather than distally. Conclusion: Our cohort study found older age, age over 70 with BMI of less than 25, osteoporosis, and Parkinson disease were associated with increased risk for early postoperative PPFx following DA approach THA. Intraoperative fractures may occur with disproportionate proximal femoral canal fill. Further study can evaluate whether cemented femoral components may mitigate risk in these patient populations.
Project description:BackgroundBone deficiencies in dysplastic acetabula create technical difficulties during total hip arthroplasty (THA). Bulk femoral head autograft (FHA) is one method to increase cup coverage and bone stock of the true acetabulum; however, only limited data exist on its efficacy through a direct anterior approach (DAA). This study aimed to evaluate the outcomes of FHA during THA via a DAA in dysplastic hips.MethodsRetrospective review of 34 patients (41 hips) with hip dysplasia (Crowe I-III) who underwent primary THA via a DAA with FHA at a single institution was performed. Surgical procedures were performed on a traction table with intraoperative fluoroscopy and highly porous-coated cup placement in the true acetabulum. Patients were assessed clinically and radiographically at a minimum of 2 years postoperatively (range, 2 to 7).ResultsThe average modified Harris Hip Score improved from 31.9 ± 10.8 to 94.1 ± 5.8, Merle d'Aubigné Hip Score from 7.5 ± 2.8 to 16.6 ± 1.1, and visual analog pain score from 7.9 ± 2.7 to 1.4 ± 1.4 (all P < .001). All hips had an "anatomic" inferomedial cup position postoperatively, with an average increase in horizontal coverage of 43.4%. Mean postoperative limb-length discrepancy improved from 21.8 ± 16.1 mm to 1.6 ± 5.7 mm (P < .001). There were no cases of revision THA, nor complications such as dislocation, infection, or osteolysis.ConclusionReconstructing dysplastic acetabula (Crowe I-III) with FHA during THA can be successfully accomplished via the DAA with increased acetabular bone stock and accurate correction of limb-length discrepancy.