Is there still a role for threaded acetabular cups?

The Insertion of Threaded Acetabulum Components: Indications According to Specific Acetabulum Anatomy and Methods to Avoid Pitfalls

New-generation threaded acetabulum components have been used in total hip arthroplasty (THA) with good outcomes. We have extensively used the EcoFit® SC cup (Implantcast, Buxtehude, Germany) in our practice. In this report, we present some major complications related to the use of this implant, as well as insights regarding the surgical technique to avoid such adverse effects. Furthermore, we attempt to describe certain contraindications for using threaded cups in THA, taking into account specific patient anatomy and intraoperative acetabulum preparation. We have observed acetabulum roof and posterior wall fractures, as well as incomplete placement of the component. Ensuring the meticulous preparation of the peripheral rim of the acetabulum is crucial to prevent incomplete placement since threaded components have a larger diameter than that of the reamers used to prepare the acetabulum. Additionally, when dealing with the acetabula where the posterior or anterior walls have thinned, it is advisable to refrain from using a threaded cup to avoid the risk of intraoperative fractures caused by the torque forces exerted during implant insertion.

Modified Anterolateral Minimally Invasive Surgery (ALMIS) for Total Hip Replacement: Anatomical Considerations, Range of Motion and Clinical Outcomes

Background and Objectives: In the modified anterolateral minimally invasive surgery (ALMIS) for total hip arthroplasty (THA), the intermuscular plane between the tensor fasciae latae and the gluteus maximus (GM) is exposed, while the anterior ¼ of the GM is detached. There are scarce data regarding this surgical approach. The purpose of the present study is to thoroughly describe this approach, encompassing the anatomical background, and to present the results of a retrospective two-center study of 603 patients. Materials and Methods: The present study includes a two-center retrospective observational cohort of 603 patients undergoing the ALMIS technique with minimum 5-year follow-up. Demographics were recorded, while range of motion (ROM) of the hip joint and the Harris Hip Score (HHS) were evaluated preoperatively, at 1, 3 and 12 months postoperatively and at the final follow-up (>5 years). Surgery-related complications were also recorded. Results: The studied population's mean age was 69.4 years, while most of them were females (397; 65.8%). The mean follow-up was 6.9 years. The median HHS at the 1-month follow-up was 74, compared to the 47 preoperatively (p-value < 0.0001). At the final follow-up, median HHS was 94. At the 1-month follow-up, mean adduction was 19.9° (compared to 15.4° preoperatively; p < 0.0001), mean abduction 24.3° (18.2° preoperatively; p < 0.0001), mean flexion 107.8° (79.1° preoperatively; p < 0.0001), mean external rotation 20.1° (12.1° preoperatively; p < 0.0001) and mean internal rotation 15.3° (7.2° preoperatively; p < 0.0001). ROM further improved until the final follow-up; mean adduction reached 22°, mean abduction 27.1°, mean flexion 119.8°, mean external rotation 24.4° and mean internal rotation 19.7°. Regarding complications, 1.3% of the sample suffered anterior traumatic dislocation, in 1.8% an intraoperative femoral fracture occurred, while 1.2% suffered periprosthetic joint infection. Conclusions: The modified ALMIS technique exhibited excellent clinical outcomes at short-, mid- and long-term follow-up, by significantly improving hip ROM and the HHS. Careful utilization of this technique, after adequate training, should yield favorable outcomes, while minimal major complications should be expected.

Early Clinical and Radiographic Outcomes of Total Hip Arthroplasty with DELTA ST-C Cup and MINIMA S Stem

Background and Objectives: The uncemented threaded DELTA ST-C cup was introduced in last few years. It has a hemispheric shell, consisting of Ti6Al4V titanium alloy. The MINIMA S stem was developed according to the principles of proximal-loading and extended metaphyseal geometry applied to a short stem. The purpose of the study was to assess the clinical and radiographic outcomes and the short- and mid-term survivorship of the DELTA ST-C cup and MINIMA S stem in patients undergoing total hip arthroplasty (THA). The present is the first study to report outcomes and implant survivorship of the DELTA ST-C cup coupled with the MINIMA S femoral stem. Materials and Methods: The present study is a retrospective observational cohort study of a prospectively maintained database, evaluating clinical outcomes and implant survivorship in 95 patients undergoing THA with the MINIMA stem coupled with the DELTA ST-C cup with at least a 3-year follow-up. The clinical evaluation was assessed with a change in the Harris hip score (HHS), while the radiographic evaluation included anteroposterior views of the pelvis and lateral views of the affected hip. Results: The enrolled population's mean age was 69.3 years and most patients were female (64%). The MINIMA S standard stem was implanted in 68 patients (72%), the lateralized stem was implanted in 27 (28%), and the mean acetabular inclination was 48.2°. The HHS improved significantly from the preoperative value (median 46, IQR: 38-55), already at 1 month after surgery (median 76, IQR: 66-77), reaching excellent results at 1 year and 3 years postoperatively (median 96, IQR: 91-100). X-rays demonstrated good implant stability and biomechanics parameter restorations revealed no sign of subsidence, and the presence of radiolucent lines greater than 2 mm in the short stem area in five cases and in the acetabulum in one were not clinically significant. No revisions have been performed so far. Conclusions: The MINIMA S stem coupled with the DELTA ST-C cup demonstrated very good clinical and radiological results with a significant increase of the Harris hip score at short- and mid-term follow-up. This is the first study evaluating the DELTA ST-C cup, showing promising outcomes during the study's follow-up. The MINIMA S stem has been evaluated in a very few studies. However, the combination with this particular cup had not yet been studied. The design of the stem and the cup ensures primary stability and excellent early term outcomes, moreover the study demonstrates extraordinary implant survivorship, equal to 100%.

BestBET: Is cross sectional imaging of the hip necessary in patients with isolated greater trochanter fracture?

A Best Evidence Topic review was undertaken to clarify whether patients with apparently isolated greater trochanter fracture on plain X-ray require urgent cross sectional imaging. A literature search was performed to establish what proportion of these patients have clinically important intertrochanteric extension. 11 papers were included showing intertrochanteric extension in 54% using magnetic resonance imaging and computed tomography and surgical management was in 37% but with marked disparity in the data. Further work is needed to completely answer this question, and to find the most clinically useful predictors of fracture completion and displacement.