Pelvic tilt and functional acetabular position after total hip arthroplasty: an EOS 2D/3D radiographic study.

PURPOSE: In total hip arthroplasty (THA), the functional anatomy of the spinopelvic unit should be taken into account to provide the correct functional positioning of the implant. The relationship between the spine and the pelvis in the sagittal plane is represented by pelvic tilt (PT). The sacral slope (SS) has been proposed as a more reliable parameter than the anterior pelvic plane (APP) to express the PT. This study investigated the relationship between the APP and the SS; and the relationship between the APP and the SS, respectively, with the postoperative acetabular orientation. METHODS: 45 patients undergoing primary THA were prospectively enrolled. The EOS 2D/3D system was used to perform the radiographic evaluation before and 3 months after surgery. The following parameters were measured in both standing and sitting position: SS, APP, acetabular anteversion (AA) and inclination (AI). RESULTS: The SS values did not show any correlation with the values of the APP angle. The changes of the SS in the transition from the standing to the sitting position significantly correlated with the changes of the AA (r = -0.61; p < 0.0001). A weak correlation was found between the APP angle and the AA in standing position (r = -0.35; p = 0.02). CONCLUSIONS: The SS accurately expresses the functional orientation of the pelvis in the sagittal plane, and the functional orientation of the cup after hip replacement. Therefore, SS could be taken into account by navigation systems in order to achieve a patient-specific functional position of the acetabular cup.

Blood loss in primary total hip arthroplasty with a short versus conventional cementless stem: a retrospective cohort study.

INTRODUCTION: To evaluate the impact of short cementless stem on several clinical and radiographic outcomes, with particular focus on blood loss, in comparison with conventional cementless stem in total hip arthroplasty (THA). MATERIALS AND METHODS: Patients undergoing THA with GTS short stem or CLS conventional stem were included. Clinical data were retrospectively collected including preoperative and postoperative day 1 value for haemoglobin (HB); rate of postoperative blood transfusions; intraoperative bone infractions; stem alignment; 5-year follow-up Harris Hip Score (HHS) and rate of stem revision at 5 years of follow-up of the short and conventional cementless stem. RESULTS: GTS and CLS stem group included 374 and 321 patients, respectively. The mean difference between the preoperative and postoperative day 1 HB value was 3.98 g/dL (SD 1.12) and 3.67 g/dL (SD 1.19) in the GTS and CLS group, respectively, which correspond to a crude effect (ß) of 0.32 (95% CI 0.15; 0.49) and adjusted effect of 0.11 (95% CI - 0.08; 0.3). GTS group reported a significantly higher number of patients with excellent results in terms of HHS (p = 0.001). The rate of intraoperative bone infractions was 1.6% and 0.3% in the GTS and CLS group, respectively (p = 0.013). At radiographic assessment, the rate of varus position of the stem was 14% in the GTS group and 6% in the CLS group (p < 0.0001). The rate of stem revision at 5 years of follow-up was 0.8% and 0.4% in the GTS and CLS group, respectively (p = 0.63). CONCLUSIONS: GTS short stem was not associated with a clinically significant lower blood loss in the immediately postoperative period. Unadjusted exploratory analyses show that GTS stem provides the same results of CLS stem in terms of HHS and rate of stem revision at 5 years of follow-up.

Total Hip Arthroplasty With a Monoblock Conical Stem in Dysplastic Hips: A 20-Year Follow-Up Study.

BACKGROUND: Total hip arthroplasty in patients with hip dysplasia is challenging as a result of complex anatomic deformities in the hip. The aim of the study was to evaluate the survivorship, the clinical and radiographic outcomes of cementless Wagner Cone stem in patients with dysplastic hip. METHODS: This retrospective study reports on 102 patients (135 hips) who have undergone total hip arthroplasty between 1993 and 1997. The mean age of patients was 51 years (range, 21-73). Minimum follow-up was 20 years. According to the Crowe classification, 38 hips presented dysplasia of grade I, 41 of grade II, 37 of grade III, and 19 of grade IV. RESULTS: Kaplan-Meier survivorship for aseptic loosening was 97% (95% confidence interval, 94.4-99.6) at 20 years. The average Harris hip score increased from 43.4 points (range, 22-51) to 86.4 points (range, 39-100) (P < .0001) and average Merle d'Aubignè score increased from 8.4 (range, 4-13) to 15 (range, 5-18) (P < .0001); at the last follow-up, average University of California at Los Angeles activity score and visual analog score were 4.53 (range, 1-9) and 1.25 (range, 0-6), respectively; 17% of heterotopic ossification and 19.2% of radiolucency lines around the stem were reported. CONCLUSION: Monoblock Wagner Cone stem is a reliable option in dysplastic hip with an excellent survivorship and good clinical and radiographic outcome in the long term.

Total hip arthroplasty with a monoblock conical stem and subtrochanteric transverse shortening osteotomy in Crowe type IV dysplastic hips.

PURPOSE: This series assessed the clinical and radiographic outcomes of total hip arthroplasty (THA) with femoral shortening osteotomy for the management of patients with Crowe type IV hip dysplasia. METHODS: Only patients with Crowe type IV hip dysplasia who underwent primary THA combined with a subtrochanteric transverse osteotomy with an uncemented monoblock conical stem were included. The clinical and radiographic evaluations were performed before and immediately after surgery, and at last follow-up. The hip function was assessed with the Harris Hip Score (HHS). RESULTS: Seventy-four patients (102 hips) with a mean age of 53.9 (range, 20-83) were evaluated at an average follow-up of 11.3 years (range, 5-25). Stem revision occurred in two (1.9%) cases, with a survivorship of 95.9% (95%IC, 91.9-99.9%) at ten years. The average HHS increased from 44 (range, 15-78) pre-operatively to 90.3 (range, 62-100) at last follow-up (p < 0.001). Osteotomy site non-union and early dislocation were observed in 3.9 and 3.8%, respectively. No cases of nerve palsy were reported. CONCLUSIONS: THA with a monoblock conical stem associated with subtrochanteric transverse osteotomy provides good long-term survival, clinical and radiographic results. It may be considered an effective management of patients with Crowe IV hip dysplasia.