Extended Trochanteric Osteotomy with Intermediate Resection Arthroplasty Is Safe for Use in Two-Stage Revision Total Hip Arthroplasty for Infection

Background: This study sought to compare the results of two-stage revision total hip arthroplasty (THA) for periprosthetic infection (PJI) in patients with and without the use of an extended trochanteric osteotomy (ETO) for removal of a well-fixed femoral stem or cement. Methods: Thirty-two patients who had undergone an ETO as part of a two-stage revision without spacer placement were matched 1:2 with a cohort of sixty-four patients of the same sex and age who had stem removal without any osteotomy. Clinical outcomes including interim revision, reinfection and aseptic failure rates were evaluated. Modified Harris hip scores (mHHS) were calculated. Minimum follow-up was two years. Results: Patients undergoing ETO had a significantly lower rate of interim re-debridement compared to non-ETO patients (0% vs. 14.1%, p = 0.026). Reinfection following reimplantation was similar in both groups (12.5% in ETO patients vs. 9.4% in non-ETO patients, p = 0.365). Revision for aseptic reason was necessary in 12.5% in the ETO group and 14.1% in the non-ETO group (p = 0.833). Periprosthetic femoral fractures were seen in three patients (3.1%), of which all occurred in non-ETO patients. Dislocation was the most common complication, which was equally distributed in both groups (12.5%). The mean mHHS was 37.7 in the ETO group and 37.3 in the non-ETO group, and these scores improved significantly in both groups following reimplantation (p < 0.01). Conclusion: ETO without the use of spacer is a safe and effective method to manage patients with well-fixed femoral stems and for thorough cement removal in two-stage revision THA for PJI. While it might reduce the rate of repeated debridement in the interim period, the use of ETO appears to lead to similar reinfection rates following reimplantation.

Patient-reported outcome after primary and aseptic revision hip arthroplasty: 1-year follow-up of 3,559 primary and 406 revision THAs in an institutional registry

Background and purpose — Patient-reported outcomes (PROMs) after primary total hip arthroplasty (THA) and revision THA are important information in the preoperative shared decision-making process. We present 1-year results on pain, function, and quality of life following primary and revision THA. Patients and methods — From 2010 to 2018, 3,559 primary THA and 406 revision THAs were included in our institutional quality registry. PROMs were registered preoperatively, 3 months, and 1 year after surgery, numeric rating scale (0–10) for pain during mobilization and at rest, healthrelated quality of life (EQ-5D), and a hip-specific physical function score (HOOS-PS). 2 anchor questions were asked 1 year after surgery concerning joint function and willingness to go through surgery again. Results — There were statistically significant improvements in all PROMs at the 3-month follow-up in both groups. All PROMs improved more in the primary group relative to the revision group. 1 year after surgery, pain during mobilization was reduced with a mean change of 5.1 (SD 2.6) for primary THA and 2.9 (SD 3.0) for revision THA. 93% of primary THA patients reported both better function 1 year after surgery and that they would have gone through surgery again, compared with 78% and 79% in the revision THA group. Interpretation — Primary THA patients reported better function and more pain relief than the revision THA group 1 year after surgery. Pain during mobilization shows the most marked improvement in both groups, which is important preoperative information for patients.

Use of a New Off-the-shelf 3D-printed Trabecular Titanium Acetabular Cup in Chinese Patients Undergoing Hip Revision Surgery: Short- to Mid-term Clinical and Radiological Outcomes

Background: Revision total hip arthroplasty (THA) has been a challenge for surgeons. The purpose of this study was to explore the short-to mid-term clinical and radiological outcomes of Chinese patients who underwent revision THA using a new off-the-shelf three-dimensional (3D)-printed trabecular titanium (TT) acetabular cup by comparison with a conventional porous coated titanium acetabular cup, to provide a reference for the recommendation of this prostheses.Methods: A retrospective analysis of 57 patients (57 hips) who received revision THA was performed from January 2016 to June 2019. A total of 23 patients received 3D-printed cups (observation group) and 34 patients received non-3D-printed cups (control group). Clinical scores including Visual Analogue Scale (VAS), Harris Hip Score (HHS) and Short Form 36 (SF-36), upward movement of the hip center of rotation（HCOR）and limb-length discrepancy (LLD), stabilization and bone ingrowth of cups were compared between two groups. The multivariate linear regression was used to determine the factors potentially influencing the HHS score. Postoperative complications in the two groups were also recorded. Results: All 57 patients were routinely followed up. The average follow-up durations in the control and observation groups were 43.57 ± 13.68 (24–65) months and 41.82 ± 11.44 (24–64) months, respectively (p = 0.618). The postoperative clinical scores significantly improved in both groups compared to the preoperative scores (p < 0.05). The VAS score did not significantly differ between the groups at 3 or 12 months postoperatively, or at the last follow-up (p > 0.05). The HHS and SF-36 scores did not significantly differ between the groups at 3 months postoperatively (p > 0.05) but differed at 12 months postoperatively and the last follow-up (p < 0.05). Compared with the control group, the postoperative recovery of HCOR and LLD was better in the observation group (p < 0.05). All cups remained stable, with no loosening throughout the follow-up period. But the observation group had a significantly better rate of bone ingrowth compared to the control group (p = 0.037). Multivariate linear regression analysis showed that different cup types, upward movement of the HCOR, and LLD influenced the HHS score at the last follow-up (p < 0.05). None of the patients exhibited severe postoperative complications.Conclusion: The new off-the-shelf 3D-printed TT acetabular cup demonstrated encouraging short-to mid-term clinical outcomes in Chinese patients. It can effectively relieve pain, improve hip function, provide satisfactory biological fixation and high survival rate. But further follow up is necessary to assess its long-term outcomes.

Evaluation of the feasibility of acetabular cup pre-determination in revision total hip arthroplasty via X-ray of the bone stock of the anterosuperior acetabulum

Purpose This study was aimed to explore (1) location on AP pelvic X-ray that displayed bone stock in anterosuperior acetabulum; (2) whether X-ray could provide enough evidence to evaluate whether bone stock could provide support for acetabular cup; (3) criteria to determine whether anterosuperior bone stock could provide sufficient support for cup on X-ray. Methods Our study retrospectively collected 43 patients who underwent revision THA for cup loosening from 2014 to 2019. The position of anterosuperior acetabular bone stock was compared between X-ray and CT-based 3-D reconstruction. Seventy-millimeter acetabular cup was implanted simulatively to obtain the contact line between acetabular cup and superolateral remaining bone stock. The contact line length and the angle were measured. Patients were divided into cup group and cage group, and ROC curves of both contact line length and angle were drawn. Results The superolateral part of acetabulum on X-ray could reflect the anterosuperior host bone stock of acetabulum according to the comparison of anteroposterior pelvic X-ray and 3-D reconstruction. Critical point was chosen when we got the highest sensitivity with a 100% specificity in ROC curves. The critical values of contact length and angle were 15.58 mm and 25.5°. Conclusions Surgeons could assess the anterosuperior bone stock of acetabulum by AP pelvic X-ray to decide whether revision could be done merely using cup or need customized cage. Clinically, when contact line length was larger than 16 mm or contact angle was larger than 25.5°, adoption of cup could obtain primary stability in the revision surgery in most cases.

Intrapelvic Pseudotumor Causing Neuropathy and Vascular Obstruction After Revision Total Hip Arthroplasty: A Case Report

Background: There is a growing body of recent literature regarding the occurrence of pseudotumors associated with modular junctions and various bearing surfaces after total hip arthroplasty (THA). Revision surgery is often technically challenging and high complication rates have been reported. The optimal management of these patients and outcomes after operative treatment remain poorly understood. Methods: We report the case of a 77-year-old male with progressive unilateral lower extremity swelling, pain, and neuropathy 9 years after revision THA for polyethylene liner wear. Imaging and biopsy confirmed a massive intrapelvic pseudotumor exerting compressive effects. Radiographs demonstrated extensive femoral and pelvic osteolysis without evidence of component loosening. Debulking of the intrapelvic portion of the pseudotumor was performed via the lateral window of the ilioinguinal approach with component retention. Results: Debulking of the intrapelvic mass resulted in resolution of symptoms. One year postoperatively the patient reported pain free ambulation using a walker and no recurrence of symptoms. Radiographs demonstrated stable THA components in comparison with preoperative films. Discussion and Conclusion: This case demonstrates a rare finding of intrapelvic pseudotumor causing neurovascular compression after revision THA. Clinicians should be aware of intrapelvic pseudotumor as a possible cause of limb swelling and neuropathy, and that debulking of the mass is a potential treatment option in the setting of well-fixed implants.

Postoperative excessive external femoral rotation in revision total hip arthroplasty is associated with muscle weakness in iliopsoas and gluteus medius and risk for hip dislocation

Background Excessive external femoral rotation (FR) can functionally increase stem anteversion (SA) and is often observed at an early stage after surgery in revision total hip arthroplasty (THA). This study was conducted to investigate the prevalence of external FR, identify the factors associated with external FR, and determine the association of FR and other factors with hip dislocation in revision THA. Methods We enrolled 51 revision THA patients (55 hip cases). The patient background, angle of anatomical and functional SA, FR angle, sizes and densities of muscles around the hip joint, impingement distance, and consequence of postoperative hip dislocation were assessed by reviewing their medical history and imaging data that includes computed tomography (CT) scans before and after surgery. Results Forty-five hip cases (81.8%) showed external FR (mean 13.0°). External FR was significantly correlated with anatomical SA (r = − 0.54) and increase in functional SA (r = 0.36), which was significantly correlated with impingement distance (r = 0.46). The independent factors associated with external FR in multivariate analysis were the anatomical SA, CT densities of the psoas, gluteus medius and maximus muscles, and 2-stage revision (R2 = 0.559). During follow-up period, eight cases of revision THA showed hip dislocation. FR, functional SA, impingement distance, CT density of psoas and gluteus medius muscle, body mass index, number of past operation, and ratio of 2-stage revision THA were significantly different between cases with dislocation and non-dislocation. The odds ratio of FR and impingement distance for hip dislocation was identified as 1.061(95% confidence interval (CI): 1.011–1.114) and 0.901 (95% CI 0.820–0.991), respectively. Conclusions Revision THA frequently causes an external FR that functionally increases the SA and impingement risk, particularly in hips with 2-stage revision with psoas and gluteus medius muscle atrophy. Patients who have undergone revision THA and have an excessive external FR may require careful monitoring for possible hip dislocation due to hip joint instability and impingement.