Bone defect map of the true acetabulum in hip dysplasia (Crowe type II and III) based on three-dimensional image reconstruction analysis

The high hip center technique (HHC) is considered to be feasible for acetabular reconstruction in patients with DDH, but there is little in-depth study of its specific impact on Crowe type II and III DDH. The purpose of this study was to simultaneously analyze the effect of HHC on bone coverage of the cup (CC) in the acetabular reconstruction of type II and III DDH patients and to propose a map of acetabular bone defects from the perspective of the cup. Forty-nine hip CT data of 39 patients with DDH (Crowe type II and III) were collected to simulate acetabular reconstruction by cup models of different sizes (diameter 38mm–50 mm, 2 mm increment) with the HHC technique. The frequency distribution was plotted by overlapping the portions of the 44 mm cups that were not covered by the host bone. The mean CC of cups with sizes of 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, and 50 mm at the true acetabula were 77.85%, 76.71%, 75.73%, 74.56%, 73.68%, 72.51%, and 71.75%, respectively, and the maximum CC increments were 21.24%, 21.58%, 20.86%, 20.04%, 18.62%, 17.18%, and 15.42% (P < 0.001), respectively, after the cups were elevated from the true acetabula. The bone defect map shows that 95% of type II and III DDH acetabula had posterosuperior bone defects, and approximately 60% were located outside the force line of the hip joint. Acetabular cups can meet a CC of more than 70% at the true acetabulum, and approximately 60% of Crowe type II and III DDH patients can obtain satisfactory CC at the true acetabulum by using a 44-mm cup without additional operations.

Acetabular reconstruction with femoral head autograft in primary total hip arthroplasty through a direct anterior approach is a reliable option for patients with secondary osteoarthritis due to developmental dysplasia of the hip

Background Developmental dysplasia is challenging to treat with total hip arthroplasty via the direct anterior approach (DAA). Reconstructing the former anatomy while restoring the acetabular bone stock for future revisions in this young patient collective combined with the known advantages of the DAA would be desirable. The purpose of this study was to analyze the feasibility, radiographic outcome and clinical outcome of primary uncemented total hip arthroplasty with bulk femoral head autograft for acetabular augmentation through a DAA with a minimal follow-up of 12 months. Methods A retrospective, consecutive series from March 2006 to March 2018 of 29 primary total hip arthroplasty with acetabular augmentation with bulk femoral head autograft through a direct anterior approach was identified. All complications, reoperations and failures were analyzed. Radiographic and clinical outcome was measured. Results 24 patients (29 hips) with a mean age of 43 (18–75) years and a mean follow-up of 35 months (12–137) were included. Surgical indication was secondary osteoarthritis for developmental dysplasia of the hip (Hartofilakidis Grade A (n = 19), B (n = 10)) in all cases. We noted no conversion of the approach, no dislocation and no acetabular loosening. The center of rotation was significantly distalized by a mean of 9 mm (0–23) and significantly medialized by a mean of 18 mm (6–29). The bone graft was fully integrated after 12 months in all cases. Conclusion Acetabular reconstruction with femoral head autograft in primary THA through a direct anterior approach seems to be a reliable option for the treatment of secondary osteoarthritis in patients with DDH Hartofilakidis grade A and B. Prospective cohort studies with a large sample population and a long-term follow-up are necessary to confirm our findings.

A New Method to Evaluate Acetabular Bone Defect in Patients With Crowe Type Ⅱ and Type Ⅲ Developmental Dysplasia of the Hip: Acetabular Reconstruction Based on Three-dimensional Reconstruction Images

This study evaluated the cup coverage(CC) of acetabular cup models with different sizes in patients with Crowe type Ⅱ and type Ⅲ DDH by the high hip center technique(HHC), the results shows that the CC of cup sizes with 38mm, 40mm, 42mm, 44mm, 46mm, 48mm, and 50 mm increased by 21.24%, 21.58%, 20.86%, 20.04%, 18.62%, 17.18%, and 15.42% (P<0.001) respectively as the cups elevated from the true acetabula until the maximum coverage were achieved. What surprising is the mean CC at the true acetabula were 77.85%, 76.71%, 75.73%, 74.56%, 73.68%, 72.51%, and 71.75%, respectively. So, we draw a distribution frequency map of uncovered portion of all 44-mm cups at the true acetabula to illustrate the distribution of bone defects of the acetabulum. The map shows that 95% of type Ⅱ and type Ⅲ DDH acetabula had bone defects in posterosuperior, and 60% were located outside the force line of the hip joint.Here comes to a conclusion that acetabular cups can meet the CC of more than 70% at the true acetabulum, and 60% of Crowe type Ⅱ and type Ⅲ DDH patients can obtain satisfactory CC at the true acetabulum by using a 44-mm cup without additional operation.

The use of a non-biological, bridging, antiprotrusio cage in complex revision hip arthroplasty and periacetabular reconstructive oncologic surgery. Is still today a valid option?: A mid/long-term survival and complications’ analysis

Introduction Burch–Schneider-like antiprotrusio cages (B-SlAC) still remain helpful implants to bridge severe periacetabular bone losses. The purpose of this study was to evaluate outcomes and estimate both cages’ failures and complication risks in a series of B-SlAC implanted in revision of failed total hip arthroplasties (THA) or after resection of periacetabular primary or secondary bone malignancies. Risk factors enhancing the chance of dislocations and infections were checked. Materials and methods We evaluated 73 patients who received a B-SlAC from January 2008 to January 2018. Group A, 40 oncological cases (22 primary tumors; 18 metastases); Group B, 33 failed THAs. We compared both Kaplan–Meier estimates of risk of failure and complication with the cumulative incidence function, taking account the competing risk of death. Cox proportional hazards model was utilized to identify possible predictors of instability and infection. Harris hip score HHS was used to record clinical outcomes. Results Medium follow-up was 80 months (24–137). Average final HHS was 61 (28–92), with no differences within the two groups (p > 0.05). The probabilities of failure and complications were 57% and 26%, respectively, lower in the oncologic group than in the rTHA group (p =0 .176; risk 0.43) (p = 0.52; risk 0.74). Extended ileo-femoral approach and proximal femur replacement (p =0.02, risk ratio = 3.2; p = 0.04, rr = 2.1) were two significant independent predictors for dislocations, while belonging to group B (p = 0.04, rr = 2.6) was predictable for infections. Conclusion Burch–Schneider-like antiprotrusio cages are a classical non-biological acetabular reconstruction method that surgeons should bear in mind when facing gross periacetabular bone losses, independently of their cause. However, dislocation and infection rates are high. Whenever possible, we suggest preserving the proximal femur in revision THA, and to use a less-invasive postero-lateral approach to reduce dislocation rates in non-oncologic cases.

Feasibility And Availability of Standard-Sized Cup At The True Acetabulum In Acetabular Reconstruction of Crowe Type IV Hip Dysplasia

Background: This study aimed to investigate the morphological features and 2D/3D coverage parameters of the true acetabulum of Crowe type IV hips and to identify the optimal component center of standard-sized cup implantation.Methods: A total of 42 Crowe IV hips in 37 patients and 36 normal hips were included in the present study. Based on 3D reconstruction, anatomy and volume of the true acetabulum were measured quantitatively. Through simulated implantation, the feasibility of standard-sized cup implantation was evaluated by cup-based morphological assessments and coverage parameters. Eventually, bony landmarks for optimal component center location were determined. Mean follow-up was 4.7 years (1.2 to 6.3 years).Results: All the dysplastic hips were placed with standard-size acetabular implant (44.67mm, 44 to 48mm) successfully, with no acetabular implant loosening during the follow-up period. Compared with control group, the dysplastic acetabulum was more anteverted and abductive, with a thicker medial wall. According to the true acetabulum, bone stock is relatively sufficient in the posterior direction and prominently deficient in the anterosuperior and superior direction. Average 3D component coverage can reach 79.89% by standard-sized cup implantation at the true acetabulum. Regarding the component opening plane, the optimal component center located at the midpoint between the superolateral and posteroinferior point of the true acetabulum. Conclusion: Standard cup implantation is feasible and available in Crowe IV hip at the true acetabulum. The optimal component center was determined to be relatively constant based on the useful bony landmarks.Level of evidence: Therapeutic Level 3b.