Acetabular Side Research Articles

The advantages of artificial intelligence-assisted total hip arthroplasty: A randomized controlled trial followed by 12 months

ObjectionThe rapid advancement of artificial intelligence has brought significant breakthroughs to various medical disciplines，This study aimed to compare perioperative factors and postoperative hip function recovery in primary total hip arthroplasty (THA)by evaluating the use of an artificial intelligence (AI) preoperative planning system versus traditional two-dimensional X-ray planning. Patients and methodsA total of 45 eligible patients underwent primary THA at Beijing Shijitan Hospital, Capital Medical University, between July 2022 and August 2022. The patients were randomly assigned to either the experimental group (n = 19) or the control group (n = 26). The experimental group utilized AI planning, while the control group employed traditional two-dimensional X-ray planning. Statistical analysis was performed to compare the accuracy of prosthesis prediction, operation time, intraoperative blood loss, frequency of intraoperative model testing, length of hospital stay, postoperative imaging data, and postoperative hip function scores. These comparisons were made to assess the effects of different preoperative planning methods on perioperative and postoperative hip function recovery. ResultsThe accuracy of preoperative planning for the acetabular and femoral sides in AI-assisted total hip arthroplasty was 84.2 % and 89.5 %, respectively, which was significantly better than that of the traditional two-dimensional X-ray planning group (P < 0.05). The operation time for AI-assisted total hip arthroplasty was 104.32 ± 18.10 min, which was shorter than that of the traditional two-dimensional X-ray planning group (P < 0.05). At 3 months post-operation, the grade of Harris score for hip function in the AI planning group was significantly better than that in the traditional two-dimensional X-ray planning group (P < 0.05). The average postoperative Harris score of the artificial intelligence group was higher than that of the traditional two-dimensional X-ray planning (P < 0.05). ConclusionArtificial intelligence-assisted total hip arthroplasty demonstrated superior accuracy in prosthesis prediction, shorter operation time, higher average Harris score at postoperative follow-up, and better hip function recovery at 3 months compared to traditional two-dimensional X-ray planning. Level of evidenceIII, case-control study.

Design, fabrication, and clinical characterization of additively manufactured tantalum hip joint prosthesis

Abstract The joint prosthesis plays a vital role in the outcome of total hip arthroplasty. The key factors that determine the performance of joint prostheses are the materials used and the structural design of the prosthesis. This study aimed to fabricate a porous tantalum (Ta) hip prosthesis using selective laser melting (SLM) technology. The feasibility of SLM Ta use in hip prosthesis was verified by studying its chemical composition, metallographic structure, and mechanical properties. In vitro experiments proved that SLM Ta exhibited better biological activities in promoting osteogenesis and inhibiting inflammation than SLM Ti6Al4V. Then, the topological optimization design of the femoral stem of the SLM Ta hip prosthesis was carried out by finite element simulation, and the fatigue performance of the optimized prosthesis was tested to verify the biomechanical safety of the prosthesis. A porous Ta acetabulum cup was also designed and fabricated using SLM. Its mechanical properties were then studied. Finally, clinical trials were conducted to verify the clinical efficacy of the SLM Ta hip prosthesis. The porous structure could reduce the weight of the prosthesis and stress shielding and avoid bone resorption around the prosthesis. In addition, anti-infection drugs can also be loaded into the pores for infection treatment. The acetabular cup can be custom-designed based on the severity of bone loss on the acetabular side, and the integrated acetabular cup can repair the acetabular bone defect while achieving the function of the acetabular cup.

Ganz femoral head reduction associated with coverage and containment procedures improve radiological and functional outcomes in Perthes' disease.

Ganz's studies made it possible to address joint deformities on both the femoral and acetabular side brought about by Perthes' disease. Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency, along with periacetabular osteotomy (PAO), which may enhance coverage and containment. The purpose of this study is to show the clinical and morphological outcomes of the technique and the use of an implemented planning approach. From September 2015 to December 2021, 13 FHROs were performed on 11 patients for Perthes' disease in two centres. Of these, 11 hips had an associated PAO. A specific CT- and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiological parameters (sphericity index, extrusion index, integrity of the Shenton's line, lateral centre-edge angle (LCEA), Tönnis angle), and clinical parameters (range of motion, visual analogue scale (VAS) for pain, Merle d'Aubigné-Postel score, modified Harris Hip Score (mHHS), and EuroQol five-dimension five-level health questionnaire (EQ-5D-5L)). Early and late complications were reported. The mean follow-up was 39.7 months (standard deviation (SD) 26.4). The mean age at surgery was 11.4 years (SD 1.6). No major complications were recorded. One patient required a total hip arthroplasty. Mean femoral head sphericity increased from 46.8% (SD 9.34%) to 70.2% (SD 15.44; p < 0.001); mean LCEA from 19.2° (SD 9.03°) to 44° (SD 10.27°; p < 0.001); mean extrusion index from 37.8 (SD 8.70) to 7.5 (SD 9.28; p < 0.001); and mean Tönnis angle from 16.5° (SD 12.35°) to 4.8° (SD 4.05°; p = 0.100). The mean VAS improved from 3.55 (SD 3.05) to 1.22 (1.72; p = 0.06); mean Merle d'Aubigné-Postel score from 14.55 (SD 1.74) to 16 (SD 1.6; p = 0.01); and mean mHHS from 60.6 (SD 18.06) to 81 (SD 6.63; p = 0.021). The EQ-5D-5L also showed significant improvements. FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical, and morphological outcomes in Perthes' disease. The newly introduced simulation and planning algorithm may help to further refine the technique.

Usefulness of a Cementless Highly-Porous Acetabular Cup in Rheumatoid Arthritis Patients Undergoing Total Hip Arthroplasty.

Total hip arthroplasty in patients with rheumatoid arthritis is difficult and leads to worse implant survival and higher risk for complications compared to osteoarthritis. Poor periacetabular bone quality might challenge the stability of the acetabular cup. Contemporary 3D-printed highly-porous titanium cup designs have become the benchmark for cementless implants; however, their usefulness in rheumatoid arthritis is still unclear. The purpose of this study was to assess the short-term results of the use of a highly-porous 3D-printed acetabular titanium cup in patients with rheumatoid arthritis. We studied a consecutive series of RA patients who underwent cementless THA between 2019 and 2020 in our center with the same 3D-printed highly-porous titanium acetabular cup. All patients were evaluated prospectively for a minimum 3-year follow-up with the Harris hip score, VAS and Roles and Maudsley score. Radiographic assessment focused on evidence of cup osseointegration. 37 RA patients, mean age at surgery of 51.3 years, were included. Mean follow-up was 3.2 years (3 to 4 years). By the last follow-up visit, the Harris hip score had increased significantly from 37.8 to 88.5, VAS had decreased from 6.1 to 1.0 and excellent satisfaction for 31 patients. All 5 Moore's radiographic signs were present in 35 hips, with only 4 signs present in the remaining 2 hips, thus indicating complete osseointegration of all cups. There were no complications on the acetabular side but one intraoperative proximal calcar fracture. 3D-printed highly porous implants used in primary THA worked well in patients with rheumatoid arthritis, showing excellent osseointegration and good clinical results in the short term.

Retrospective clinical study of hip replacement in the treatment of traumatic arthritis secondary to acetabular fracture

To investigate the clinical effect of total hip replacement (THA) in the treatment of traumatic arthritis secondary to acetabular fracture. From October 2019 to June 2022, 15 patients with secondary traumatic arthritis of acetabulum fracture were treated with THA. There were 8 males and 7 females, aged from 40 to 76 years old with an average of (59.20±9.46) years old. Prosthesis loosening, dislocation of hip joint, range of motion of hip joint, nerve injury and other conditions were recorded before and after surgery. Harris score, visual analogue scale (VAS) and imaging were used to evaluate hip joint function and surgical effect. Follow-up time ranged 6 to 39 months with an average of (18.33±9.27) months. All the 15 patients successfully completed the operation, no nerve and blood vessel injury during the operation, postoperative wound healing was stageⅠ, no infection, one case of acetabular side prosthesis loosening at half a year after operation, and recovered well after revision surgery, one case of hip dislocation was cured after open reduction treatment, no adverse consequences. Harris score at the last postoperative follow-up was (88.60±4.01) points, compared with the preoperative (47.20±11.77) points, the difference was statistically significant (P<0.05), and VAS at the lateat postoperative follow-up was 1 (1) points, compared with the preoperative 8 (2) points, the difference was statistically significant (P<0.05). At the last follow-up, the pain symptoms were relieved or disappeared, and the joint function was satisfactory. The imaging data of the latest follow-up showed joint was well pseudoradiated, no abnormal ossification occurred, and the prosthesis was not loose. THA is effective in the treatment of traumatic arthritis secondary to acetabular fracture and can effectively improve the quality of life of patients. Preoperative comprehensive evaluation and bone defect evaluation of patients, and intraoperative management of acetabulum, femur, internal fixation and bone defect are key factors for the success of surgery.

Advances in revision surgery after primary total hip arthroplasty for Crowe type Ⅳ developmental dysplasia of the hip

To review research advances of revision surgery after primary total hip arthroplasty (THA) for patients with Crowe type Ⅳ developmental dysplasia of the hip (DDH). The recent literature on revision surgery after primary THA in patients with Crowe type Ⅳ DDH was reviewed. The reasons for revision surgery were analyzed and the difficulties of revision surgery, the management methods, and the related prosthesis choices were summarized. Patients with Crowe type Ⅳ DDH have small anteroposterior diameter of the acetabulum, large variation in acetabular and femoral anteversion angles, severe soft tissue contractures, which make both THA and revision surgery more difficult. There are many reasons for patients undergoing revision surgery after primary THA, mainly due to aseptic loosening of the prosthesis. Therefore, it is necessary to restore anatomical structures in primary THA, as much as possible and reduce the generation of wear particles to avoid postoperative loosening of the prosthesis. Due to the anatomical characteristics of Crowe type Ⅳ DDH, the patients have acetabular and femoral bone defects, and the repair and reconstruction of bone defects become the key to revision surgery. The acetabular side is usually reconstructed with the appropriate acetabular cup or combined metal block, Cage, or custom component depending on the extent of the bone defect, while the femoral side is preferred to the S-ROM prosthesis. In addition, the prosthetic interface should be ceramic-ceramic or ceramic-highly cross-linked polyethylene wherever possible. The reasons leading to revision surgery after primary THA in patients with Crowe type Ⅳ DDH and the surgical difficulties have been clarified, and a large number of clinical studies have proposed corresponding revision modalities based on which good early- and mid-term outcomes have been obtained, but further follow-up is needed to clarify the long-term outcomes. With technological advances and the development of new materials, personalized prostheses for these patients are expected to become a reality.

Accuracy and safety of a new robotic arm for both femoral and acetabular side in total hip arthroplasty: a cadaveric study

BackgroundTo investigate the accuracy and safety of a newly constructed robotic arm which can cover the whole process of THA, we performed a series of robot-assisted total hip replacement on the cadaver.MethodsFifteen frozen cadaveric specimens (30 hips) were used for this study. In this investigation, united hip system and Longwell robotic-assisted system were used. The entire lower limb was CT scanned prior to surgery. The 3D model was produced based on CT data; the site of the prosthesis, including acetabular anteversion, inclination angle, and the position of femoral prosthesis, was planned. With the assistance of a robotic arm, the surgeon changed the parameters based on the preoperative plan and the actual condition during surgery, and completed the whole procedure. Following surgery, we measured the acetabular anteversion angle, acetabular inclination angle, femur anteversion angle, combined anteversion angle, stem angulation, and canal fill ratio.ResultsThe parameters proved that the acetabular anteversion angle was 16.85 ± 3.00°, the acetabular inclination angle was 40.38 ± 5.37°, femur anteversion angle was 15.90 ± 9.01°, combined anteversion angle was 32.75 ± 9.03°, stem angulation was 1.84 ± 0.99°, and leg length discrepancy was 2.47 ± 1.43 mm. The canal fill ratio (CFR) of femoral prosthesis of osteotomy line in sagittal section is 99.72 ± 1.54% and in coronal section is 62.94 ± 8.91%; below osteotomy line 2.5 cm in sagittal section is 100.00% and in coronal section is 81.48 ± 12.94%; below osteotomy line 7.5 cm in sagittal section is 59.51 ± 12.94% and in coronal section is 89.79 ± 11.13%; femoral shaft isthmus in sagittal section is 56.41 ± 13.80% and in coronal section is 84.95 ± 15.17%.ConclusionThe accuracy and safety of this novel robotic arm are suitable for preparing both the acetabular and femoral sides, providing evidence for clinical trial.

Both Acetabular and Femoral Reconstructions With Impaction Bone Grafting in Revision Total Hip Arthroplasty: Case Series and Literature Review

BackgroundExtensive bone loss on femur and acetabulum posed a big challenge to orthopedists in total hip revision surgeries. Impaction bone grafting (IBG) as a valuable bone preservation technique could effectively address this problem. Either IBG revision on the femoral or acetabular side was well studied, while its use on both sides in one operation was not. The aim of this study is to present the outcomes of IBG on both femoral and acetabular sides at first-time hip revision. MethodsWe retrospectively reviewed 8 patients (mean follow-up of 5.8 years) undergoing first-time revision with IBG on both acetabular and femoral sides at our institution. The Paprosky classification system was used to classify bone defects. Freeze-dried allografts and cemented prostheses were used in all patients. Postoperative complications and rerevision rates were reported. ResultsFive patients presented a Paprosky type IIC acetabular defect, 3 with a type IIIB, IIIA, and IIC defect, respectively. Three patients presented with a type IV femoral defect, 3 with a type IIIB defect, and 2 with a type II defect. Two patients developed complications, while one had an intraoperative femoral fracture and one had delayed wound healing. At the latest follow-up, no patient had rerevisions or operations related to the prosthesis. ConclusionsIBG in combination with cemented prosthesis is a profitable biological reconstruction revision technique that could provide satisfying midterm outcomes. We first propose the use of blood clots mixed with bone grafts for potential bone incorporation enhancement, while its specific effects need to be verified in further studies.

Evaluating the effectiveness of interventions targeting only the acetabular side in the surgical treatment of Legg-Calvé-Perthes disease.

This study aims to show the effectiveness of only acetabular-side surgeries for hips affected by Legg-Calvé-Perthes disease. Twelve patients who underwent two different acetabular osteotomies -pembersal osteotomy and triple osteotomy - were evaluated retrospectively. Clinically, patients were examined for hip range of motion, flexion contracture, and hip extensor and abductor strength; the results were evaluated using the Harris hip score. Radiologically, the hips were assessed according to three different radiological parameters: lateral center edge angle, acetabular width, and acetabular head index at the preoperative, early postoperative, and last follow-up periods. The hips were classified according to Herring classification preoperatively and according to Stulberg classification at the last follow-up. Statistically significant improvement was observed in patients both clinically and radiologically. It was observed that pembersal osteotomy significantly corrected the lateral center edge angle better than triple osteotomy while also correcting the other two radiological parameters, but no statistically significant difference was observed between these methods. Only acetabular-side surgeries are effective and safe methods that do not require femoral intervention for hips affected by Legg-Calvé-Perthes disease and that do not show significant complications.

GANZ HEAD REDUCTION OSTEOTOMY FOR THE TREATMENT OF FEMORAL HEAD DEFORMITIES: RADIOLOGICAL AND FUNCTIONAL OUTCOMES

Ganz's studies made it possible to address joint deformities on both femoral and acetabular side brought by the Legg-Calvè-Perthes disease (LCPD). Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency along with periacetabular osteotomy (PAO). The purpose of this study is to show the clinical and morphologic outcomes of the technique, and an implemented planning approach.From 2015 to 2023, 13 FHROs were performed on 11 patients for LCPD, in two centers. 11 of 13 hips had an associated PAO. A specific CT and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiographic parameters (sphericity index, extrusion index, integrity of the Shenton's line, LCE angle, Tonnis angle, CCD angle) and clinical parameters (ROM, VAS, Merle d'Aubigné-Postel score, modified-HHS, EQ5D-5L). Early and late complications were reported.The mean follow-up was 40 months. The mean age at surgery was 11,4 years. No major complications were recorded. One patient required a total hip arthroplasty. Femoral Head Sphericity increased from 45% to 70% (p &lt; 0,001); LCE angle from 18° to 42,8° (p &lt; 0,001); extrusion Index from 36,6 to 8 (p &lt; 0,001); Tonnis Angle from 14,4° to 6,2° (p = 0.1); CCD Angle from 131,7 to 136,5° (p &lt; 0,023). The VAS score improved from 3,25 to 0,75,(p = 0.06); Merle d'Aubigné-Postel score from 14.75 to 16 (p = 0,1); Modified-HHS from 65,6 to 89,05 (p = 0,02). The EQ 5D 5L showed significant improvements. ROM increased especially in abduction and extra-rotation.FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical and morphologic outcomes in LCPD. The newly introduced simulation and planning algorithm may help to further refine the technique.

Direct anterior approach for Crowe grade III developmental dysplasia in total hip arthroplasty

InrtroductionTHA for high dislocation due to severe acetabular dysplasia of the hip (DDH) often requires bone grafting due to bone loss on the acetabular side, have proximal femur deformity and leg length difference, making treatment difficult. Purpose: In this study, we examined the clinical and radiological outcome of 5 THAs using Direct anterior approach (DAA) for patients with DDH. ResultThe cup inclination angle was 37.2° and the anteversion angle was 18.8°. The leg length discrepancy improved from 28.8mm preoperatively to 7.95mm. The HHS significantly improved from 37.8 ​± ​7.78 preoperatively to 88 ​± ​2.35 (p ​< ​0.001) at latest follow-up. The JHEQ score also improved from 19.8 ​± ​15.1 before surgery to 64.5 ​± ​9.88 at the final survey (p ​= ​0.003). The patients were able to walk with a cane and discharged from hospital in 27 days. No postoperative complications such as dislocation or neurological disorders were observed. The limp improved in all patients 6 months after surgery, and they were able to walk without a cane. Radiologically, the autologous bone grafted on the acetabular side had healed and no stem subsidence of more than 3 mm was observed at the final observation. There was no revision case for any reason. The limp improved in all patients 6 months after surgery, and they were able to walk without a cane. There was no revision case for any reason. ConclusionDAA improved early postoperative recovery due to muscle preservation and significantly improved clinical outcomes, and it also improved leg length and prevented dislocation.

A patient-cohort study of numerical analysis on sacroiliac joint stress distribution in pre- and post-operative hip dysplasia

In acetabular dysplasia, the cartilaginous roof on the acetabular side does not fully cover the femoral head, which may lead to abnormal stress distribution in both the femoral head and pelvis. These stress changes may have implications to the adjacent sacroiliac joint (SIJ). The SIJ has a minimal range of motion and is closely coupled to the adjacent spine and pelvis. In consequence, the SIJ may react sensitively to changes in stress distribution at the acetabulum, with hypermobility-induced pain. The purpose of this study was to investigate the stress distribution of the SIJ in acetabular dysplasia, and to gain insight into the cause and mechanisms of hypermobility-induced pain at the SIJ. Finite element models of pre- and postoperative pelves of four patients with acetabular dysplasia were created and analyzed in double leg standing positions. The preoperative models were relatively inflare, the sacral nutation movement, SIJ cartilage equivalent stress, and the load on the surrounding ligaments decreased with increased posterior acetabular coverage. Acetabular morphology was shown to affect the SIJ, and improvement of the posterior acetabular coverage may help normalize load transmission of the pelvis and thus improve the stress environment of the SIJ in acetabular dysplasia.

Comparative Reliability of 3-Tesla Magnetic Resonance Imaging to Arthroscopy Findings in Femoroacetabular Impingement

Purpose: We have found that 3-tesla magnetic resonance imaging (3TMRI) is as clinically effective as magnetic resonance (MR) arthrogram when it comes to investigating patients with femoroacetabular impingement (FAI). It is also a noninvasive procedure that can be done more efficiently, with equivalent radiological and surgical outcomes. We would recommend 3TMRI as the primary investigation for patients presenting with FAI-type symptoms. Methods: This was a retrospective review of a single surgeon series of 59 operative cases, over 3 years. The inclusion criteria were arthroscopically confirmed diagnosis of FAI and preoperative imaging with 3TMRI scans. The surgical reports were analyzed and compared to the radiological reports, that were produced independently by two consultant musculoskeletal radiologists. The key findings included were the presence of labral tear, femoral CAM deformity, and acetabular and femoral cartilage damage. Results: We found that 3T MRI is sensitive in detecting the presence of labral tears and CAM deformities. (96% and 83% respectively). It was however, less sensitive in detecting femoral and acetabular cartilage damage. (50% and 69% respectively). The specificity of excluding cartilage wear on both the femoral and acetabular side was also high, (83% and 86%) but low for labral tears and CAM deformities (9% and 69%). The positive predictive value of 3TMRI was high in labral tears, CAM deformities, and acetabular wear (82%, 74%, and 97%) but low in predicting femoral cartilage damage (25%). The negative predictive value was high in detecting CAM lesions and femoral wear (80% and 94%) but low for labral tears and acetabular wear (33% and 27%). Conclusion: 3T MRI is particularly good at detecting the presence of labral tears, and CAM deformities. It is less sensitive at detecting cartilage damage, but more accurate in diagnosing the location of cartilage wear when present. This is a level 3 study, being a retrospective case–control study. The clinical relevance of this study is to determine if the less invasive 3TMRI study can be used to substitute for MR arthrography in the diagnosis of FAI in patients.

Bone Preservation in Total Hip Arthroplasty.

Preserving bone stock in younger and more active patients after total hip arthroplasty (THA) is important for future revision. Newer prosthesis designs, including short femoral stems and isoelastic acetabular cups, are likely to preserve more bone stock. However, long-term follow-up studies on bone remodeling after short-stem THA with an isoelastic monoblock acetabular cup are few. Therefore, we evaluated bone preservation after THA using these prostheses at a 5-year follow-up. This prospective observational study is a 5-year follow-up of our previously reported 2-year observational study on the same cohort of patients. We included 45 patients with primary osteoarthritis treated with a calcar-guided femoral short-stem prosthesis and a monoblock press-fit acetabular cup. We evaluated bone mineral density (BMD) around the prostheses using dual-energy X-ray absorptiometry and reported functional outcomes preoperatively and at 3, 12, 24, and 60 months postoperatively. All complications were recorded. At the final follow-up, the BMD was comparable with that at 24 months in Gruen zones 3, 4, 5, 6, and 7, whereas it significantly differed in Gruen zones 1 (P < .0001) and 2 (P < .004). On the acetabular side, the BMD leveled off similarly in all DeLee and Charnley zones between 24 and 60 months (P > .05). Moreover, all measured clinical outcomes significantly improved (P < .001). One perioperative dislocation was reported. Patients undergoing THA with a calcar-guided femoral short-stem prosthesis and a monoblock acetabular cup can expect preservation of bone stock over a longer follow-up with excellent clinical outcomes and few complications.

Integrity of the hip capsule measured with magnetic resonance imaging after capsular repair or unrepaired capsulotomy in hip arthroscopy.

BACKGROUNDCurrent literature shows no clear answer on the question how to manage the capsule after hip arthroscopy. Regarding patient reported outcome measures there seems to be no difference between capsular repair or unrepaired capsulotomy.AIMTo evaluate and compare the integrity of the hip capsule measured on a magnetic resonance imaging (MRI) scan after capsular repair or unrepaired capsulotomy.METHODSA case series study was performed; a random sample of patients included in a trial comparing capsular repair vs unrepaired capsulotomy had a postoperative MRI scan. The presence of a capsular defect and gap size were independently evaluated on MRI.RESULTSA total of 28 patients (29 hips) were included. Patient demographics were comparable between treatment groups. There were 2 capsular defects in the capsular repair group and 7 capsular defects in the unrepaired capsulotomy group (P = 0.13). In the group of patients with a defect, median gap sizes at the acetabular side were 5.9 mm (range: 2.7-9.0) in the repaired and 8.0 mm (range: 4.5-18.0) in the unrepaired group (P = 0.462). At the muscular side gap sizes were 6.6 mm (range: 4.1-9.0) in the repaired group and 11.5 mm (range: 3.0-18.0) in the unrepaired group (P = 0.857). The calculated Odds ratio (OR) for having a capsular defect with an increasing lateral center-edge (CE) angle was 1.12 (P = 0.06). The OR for having a capsular defect is lower in the group of patients that underwent a labral repair with an OR of 0.1 (P = 0.05).CONCLUSIONThere is no significant difference in capsular defects between capsular repair or unrepaired capsulotomy. Regarding clinical characteristics our case series shows that a larger CE angle increases the likelihood of a capsular defect and the presence of a labral repair decreases the likelihood of a capsular defect.

Femoral antetorsion after calcar-guided short-stem total hip arthroplasty: A cadaver study.

Calcar‐guided short stems in total hip arthroplasty (THA) permit surgeons to successfully reconstruct postoperative femoroacetabular offset, accurately restore leg length, and adequately re‐establish a wide range of caput‐collum‐diaphyseal angles. However, their effect on femoral antetorsion is less known. Indeed, controlling antetorsion of the femoral stem can be challenging because of the differences in individual femoral geometry and curvature. Therefore, we investigated if calcar‐guided short‐stem THA alters femoral antetorsion and compared it with conventional‐stem THA. Using 12 Thiel‐fixed, full‐body cadaver specimens from donors without known hip disorders, we compared an uncemented calcar‐guided femoral short‐stem prosthesis with an uncemented conventional straight‐stem prosthesis. In a paired study setup, each specimen received a calcar‐guided short stem on one side and a conventional stem on the other. On the acetabular side, all specimens received a press‐fit, monobloc acetabular cup. Femoral antetorsion angles were measured using the Waidelich method, and pre‐ and post‐operative angles of both sides were recorded. The mean preoperative femoral antetorsion angles were similar in both groups (24.8° ± 7.5° vs. 23.8° ± 6.1°, p = 0.313). Mean postoperative femoral antetorsion angles were 23.0° ± 5.5° in short‐stem and 13.5° ± 7.1° in conventional‐stem hips. Short‐stem hips had a small but nonsignificant difference in femoral antetorsion angles pre‐ and post‐operatively (1.8° ± 3.2°, p = 0.109), while the difference for conventional‐stem hips was much larger and highly significant (10.3° ± 5.8°, p < 0.001). Calcar‐guided short‐stem THA effectively restores femoral antetorsion. However, how this affects long‐term clinical outcomes and complications warrants further exploration.

Analysis of the Risk of Wear on Cemented and Uncemented Polyethylene Liners According to Different Variables in Hip Arthroplasty

Wear debris in total hip arthroplasty is one of the main causes of loosening and failure, and the optimal acetabular fixation for primary total hip arthroplasty is still controversial because there is no significant difference between cemented and uncemented types for long-term clinical and functional outcome. To assess and predict, from a theoretical viewpoint, the risk of wear with two types of polyethylene liners, cemented and uncemented, a simulation using the finite element (FE) method was carried out. The risk of wear was analyzed according to different variables: the polyethylene acetabular component’s position with respect to the center of rotation of the hip; the thickness of the polyethylene insert; the material of the femoral head; and the relationship of the cervical–diaphyseal morphology of the proximal end of the femur to the restoration of the femoral offset. In all 72 simulations studied, a difference was observed in favour of a cemented solution with respect to the risk of wear. With regard to the other variables, the acetabular fixation, the thickness of the polyethylene, and the acetabular component positioning were statistically significant. The highest values for the risk of wear corresponded to a smaller thickness (5.3 mm), and super-lateral positioning at 25 mm reached the highest value of the von Mises stress. According to our results, for the reconstruction of the acetabular side, a cemented insert with a thickness of at least 5 mm should be used at the center of rotation.

Concomitant ipsilateral acetabular and femoral fractures – an appraisal of outcomes and complications in 34 patients

Concomitant ipsilateral femoral and acetabular fractures are complex injuries which result from high-velocity trauma. Surgical treatment is the accepted management of such injuries. The objectives of this study were to evaluate the outcomes and study the complications in patients treated for concomitant ipsilateral acetabular and femoral fractures (type 'B' floating hip injuries). This retrospective study was conducted at a tertiary care teaching hospital on patients operated for type B floating hip injuries, who had completed a minimum of one-year follow-up after the surgery and whose complete records were available. Those with floating hip injuries with pelvic fractures were excluded. All patients were operated on the femoral side first, followed by the acetabular side. 34 patients were included ; most of them were young males. A road traffic accident was the most common mode, with a dashboard injury being the most common mechanism of injury. No association between the type of acetabular and femoral fractures was found. The clinical (measured with Harris hip score) and radiological (Matta's method) outcomes at the latest follow-up were excellent or good in >60% cases and had a significant association with the quality of reduction on the post-operative radiographs. Complications were seen in 12 out of the 34 patients. Type B floating hips injuries can be managed well with acceptable short-term results by following a femur first strategy. However, patients must be informed of the possible complications and the probabilities of poorer outcomes when compared to isolated acetabular or femoral fractures.

Lower Center Edge Angle and Bioipolar Cartilage Lesions Are Associated With Conversion to Hip Arthroplasty Within 2 Years Following Hip Arthroscopy: A Matched Cohort Analysis

The purpose of this study was to determine whether radiographic parameters, intraoperative findings, patient-reported outcome measures, or intraoperative interventions that were performed differentiate those patients with >2 mm of joint space who convert under two years to total hip arthroplasty (THA) after undergoing hip arthroscopy for femoroacetabular impingement (FAI) when compared to those converting after 2 years. Included in this study were patients who underwent conversion to THA within 2 years of primary hip arthroscopy from a prospectively collected patient registry from 2007 to 2017. Patients who underwent early conversions to arthroplasty were matched 1:1 with patients who converted after 2 years, based upon age and gender. Preoperative outcome scores were collected, including Short Form-12, modified Harris Hip Score, and Hip Outcome Score. Additionally, variables from the preoperative radiographic evaluation, surgical findings, and procedures performed were also compared. Forty-nine patients were included in the early conversion group and were matched with 49 patients in the later conversion group. Patients with lateral center edge angles of less than 25° were more likely to be in the early failure group [OR: 3.9; 95% CI: 1.01 to 15]. Patients with unipolar chondral defects on either the femoral (P= .128) or acetabular side (P= .656) were not at increased odds for early conversion compared to later conversion; however, those with bipolar chondral lesions at the time of surgery had increased odds of early conversions [OR: 3.3; 95% CI: 1.4 to 8] (P= .01). Neither surgical treatment nor preoperative patient-reported outcome measures were associated with early conversion. In patient with >2 mm of joint space, lateral center edge angles of less than 25° and those with bipolar articular cartilage lesions seen at the time of hip arthroscopy are at increased risk for conversion to total hip arthroplasty within two years. Level III, retrospective comparison study.

Highly Crosslinked Polyethylene Can Reduce Wear Rate in THA for High-Demand Patients: A Matched-Paired Controlled Study

BackgroundThe average age of patients benefiting from total hip arthroplasty (THA) has been declining. In addition to pain relief, patients seek to return to physical activity. However, the latter may increase polyethylene wear and therefore the potential risk of early aseptic loosening. The introduction of highly crosslinked polyethylene (HXLPE) has reduced wear rates in the general patient population. The objective of this study was to evaluate the influence of impact sports in patients operated with THA using ceramic-on-conventional polyethylene (cPE) versus ceramic-on-HXLPE, in terms of wear and function, with a minimum of five year follow-up. MethodsSixty-eight patients practicing an impact sport (University of California Los Angeles score ≥8) who underwent a primary THA were included: 34 with a ceramic-on-cPE versus 34 with a ceramic-on-HXLPE using the same cementless acetabular and femoral component. Patients were matched-paired by age, sex, BMI, and University of California Los Angeles score. The wear analysis was performed using the IMAGIKA software. The Harris hip score and hip and osteoarthritis outcome score were collected. ResultsThe linear wear rate was statistically higher (P < .0001) in the cPE group (0.13503 ± 0.0630 mm/year) than in the HXLPE group (0.03059 ± 0.0084 mm/year). Postoperatively, the increase in Harris hip score was calculated at 37.64 for the entire cohort and was comparable in both groups (P = .3674). The hip and osteoarthritis outcome score for pain (P = .0009), daily life activities (P = .0016), and quality of life (P = .0179) were significantly higher in the HXLPE group, with, between groups, a difference inferior to the reported minimal clinical important difference. Three patients exhibited signs of periprosthetic osteolysis in the cPE group, one on the femoral side and two on the acetabular side. None were observed in the HXLPE group. No revision for aseptic loosening was reported in both cohorts. ConclusionPatients partaking in impact sports and receiving a ceramic-on-HXLPE THA demonstrated lower wear and osteolysis rates than those having a ceramic-on-cPE THA, with similar functional results.