Acetabular Cup In Total Hip Arthroplasty Research Articles

Incidence and Risk Factors of Iliopsoas Tendinopathy After Total Hip Arthroplasty: A Radiographic Analysis of 1,602 Hips

BackgroundIliopsoas tendinopathy (IPT) can cause persistent groin pain and lead to dissatisfaction after total hip arthroplasty (THA). This study aimed to report the characteristics, incidences, risk factors, and treatment outcomes of IPT after THA. MethodsWe reviewed primary THAs performed at a single institution between January 2012 and May 2018. Clinical and radiographic analyses were performed on 1,602 THAs (1,370 patients). Patient characteristics, component sizes, inclination and anteversion angles, and antero-inferior cup prominence (≥8 millimeters (mm)), were compared between the groups with and without IPT. Changes in teardrop to lesser trochanter distance were measured to estimate changes in leg length and horizontal offset caused by THA. Logistic regression models were used to identify the risk factors for IPT. IPT was identified in 53 hips (3.3%). ResultsPatients with IPT had greater leg lengthening (12.3 versus 9.3 mm; P = .001) and higher prevalence of antero-inferior cup prominence (5.7 versus 0.4%; P = .002). There was no significant difference in inclination, anteversion, and horizontal offset change between the two groups. In multivariate analyses, greater leg lengthening, prominent acetabular cup, women, and higher body mass index were associated with IPT. All patients reported improvement in groin pain after arthroscopic tenotomy, while 35.7% with nonoperative management reported improvement (P < .001). ConclusionsSymptomatic IPT occurred in 53 (3.3%) of the 1,602 primary THAs. Our findings suggest that leg lengthening as well as prominent acetabular cup in THAs can be associated with the development of IPT. Arthroscopic tenotomy was effective in relieving groin pain caused by IPT.

Precision and accuracy of imageless navigation versus freehand implantation of total hip arthroplasty: A systematic review and meta-analysis.

Total hip arthroplasty (THA) is named the most successful surgical procedure of the twentieth century. To remain a success in the twenty-first century THA should meet the higher demands of patients and society with regard to technical and functional outcome, costs and implant survival. To meet these demands optimal acetabular cup positioning is necessary. An imageless navigation system (NAV) might prevent malpositioning of the acetabular cup in THA. The aim of this study has been to compare the precision and accuracy of the anteversion and inclination of the acetabular cup position after NAV implantation and after freehand implantation of THA. A systematic review and meta-analysis was conducted to assess the precision (variance) and accuracy (deviation from the target) from all available high-quality randomised control trials to date. Six out of seven studies concluded a statistically significant difference in precision in anteversion between the NAV group and the freehand group. Five out of seven studies concluded a statistically significant difference in precision in inclination. There is a significantly better accuracy for the NAV group than for the freehand group for anteversion (p=0.002) and for inclination (p=0.01). This study showed that NAV placement is more precise and has an improved accuracy for anteversion and inclination than freehand placement of the acetabular cup. However, there is a lack of evidence to support an improved functional outcome and a reduction of complications and revisions.

Assessment of Accuracy and Reliability in Acetabular Cup Placement Using an iPhone/iPad System.

Implant positioning is one of the critical factors that influences postoperative outcome of total hip arthroplasty (THA). Malpositioning of the implant may lead to an increased risk of postoperative complications such as prosthetic impingement, dislocation, restricted range of motion, polyethylene wear, and loosening. In 2012, the intraoperative use of smartphone technology in THA for improved accuracy of acetabular cup placement was reported. The purpose of this study was to examine the accuracy of an iPhone/iPad-guided technique in positioning the acetabular cup in THA compared with the reference values obtained from the image-free navigation system in a cadaveric experiment. Five hips of 5 embalmed whole-body cadavers were used in the study. Seven orthopedic surgeons (4 residents and 3 senior hip surgeons) participated in the study. All of the surgeons examined each of the 5 hips 3 times. The target angle was 38°/19° for operative inclination/anteversion angles, which corresponded to radiographic inclination/anteversion angles of 40°/15°. The simultaneous assessment using the navigation system showed mean±SD radiographic alignment angles of 39.4°±2.6° and 16.4°±2.6° for inclination and anteversion, respectively. Assessment of cup positioning based on Lewinnek's safe zone criteria showed all of the procedures (n=105) achieved acceptable alignment within the safe zone. A comparison of the performances by resident and senior hip surgeons showed no significant difference between the groups (P=.74 for inclination and P=.81 for anteversion). The iPhone/iPad technique examined in this study could achieve acceptable performance in determining cup alignment in THA regardless of the surgeon's expertise. [Orthopedics. 2016; 39(4):e621-e626.].