Paprosky Type Research Articles

Three dimensionalprinted titanium block to reconstruct severe acetabular bone defects in primary hip arthroplasty.

Total hip arthroplasty (THA) with severe acetabular bone defect remains a challenge in clinic. The purpose of this study is to investigate the treatment technique by using the three-dimensional (3D) printing technology, and analyze the feasibility and preliminary effect of 3D printed personalized titanium blocks for acetabular defect reconstruction in primary THA. The clinical data of 35 patients with Paprosky type 3 acetabular defect, who underwent initial THA with 3D-printed titanium implants in our hospital from January 2017 to December 2019, were retrospectively analyzed. Among them, 21 cases were Paprosky type 3A bone defects and 14 cases were Paprosky type 3B bone defects. The Harris Hip Score (HHS) was used to evaluate clinical outcomes, while imaging results were analyzed by hip rotation centres (V-COR and H-COR). In addition, postoperative complications were recorded. The mean follow-up was 79.4 months (ranging from 63 to 94 months) and no patient was lost to follow-up. The total in-hospital blood loss of all patients was 462.9 ± 227.8 mL, accompanied with a blood transfusion rate of 31.4%. HHS improved from 44.5 ± 10.0 preoperatively to 85.1 ± 7.4 at the last follow-up (p < 0.001). Postoperative X-rays exhibited a good match between the 3D-printed titanium block and the acetabulum. V-COR decreased from 50.1 ± 4.7mm preoperatively to 19.7 ± 1.8mm postoperatively (p < 0.001). Similarly, H-COR improved from 33.1 ± 11.8mm preoperatively to 29.7 ± 1.7mm postoperatively (p > 0.05). Additionally, there were no significant changes in V-COR and H-COR at the last follow-up (p > 0.05). During follow-up, three cases of complications were observed, including two cases of wound redness and one case of partial sciatic nerve paralysis. The 3D-printed personalized titanium block revealed accurate reconstruction, satisfactory radiographic and clinical outcomes, and low complication rates. This technique provides a reliable treatment strategy for primary THA in patients with severe acetabular bone defect.

Application of personalized three-dimensional printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects

To analyze the short-term effectiveness and safety of personalized three-dimensional (3D) printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects. A retrospective analysis was conducted on 8 patients with severe Paprosky type Ⅲ acetabular bone defects and met the selection criteria between January 2023 and June 2024. There were 3 males and 5 females, with an average age of 64.6 years ranged from 56 to 73 years. All primary replacement prostheses were non-cemented, including 1 ceramic-ceramic interface, 1 ceramic-polyethylene interface, and 6 metal-polyethylene interfaces. The time from the primary replacement to the revision was 4 days to 18 years. The reasons for revision were aseptic loosening in 5 cases, revision after exclusion in 2 cases, and repeated dislocation in 1 case. The preoperative Harris score was 39.5±3.7 and the visual analogue scale (VAS) score was 7.1±0.8. The operation time, intraoperative blood loss, hospital stay, and complications were recorded. The hip function was evaluated by Harris score, and the degree of pain was evaluated by VAS score. The acetabular cup abduction angle, anteversion angle, rotational center height, greater trochanter height, and femoral offset were measured on X-ray film. The operation time was 95-223 minutes, with an average of 151.13 minutes. The intraoperative blood loss was 600-3 500 mL, with an average of 1 250.00 mL. The hospital stay was 13-20 days, with an average of 16.88 days. All 8 patients were followed up 2-12 months, with an average of 6.4 months. One patient had poor wound healing after operation, which healed well after active symptomatic treatment. One patient had lower limb intermuscular vein thrombosis, but no thrombosis was found at last follow-up. No serious complications such as aseptic loosening, infection, dislocation, and periprosthetic fracture occurred during the follow-up. At last follow-up, the Harris score was 72.0±6.2 and the VAS score was 1.8±0.7, which were significantly different from those before operation ( t=-12.011, P<0.001; t=16.595, P<0.001). On the second day after operation, the acetabular cup abduction angle ranged from 40° to 49°, with an average of 44.18°, and the acetabular cup anteversion angle ranged from 19° to 26°, with an average of 21.36°, which were within the "Lewinneck safety zone". There was no significant difference in the rotational center height, greater trochanter height, and femoral offset between the healthy side and the affected side ( P>0.05). The use of personalized 3D printed customized prostheses for the reconstruction of severe Paprosky type Ⅲ acetabular bone defects can alleviate pain and enhances hip joint function, and have good postoperative prosthesis position, without serious complications and have good safety.

Custom-Made 3D-Printed Augments and Cages: An Effective Solution for Managing Severe Acetabular Bone Loss.

Total hip arthroplasty (THA) is recognized as one of the most effective surgical procedures for the treatment of end-stage hip arthritis. However, the increasing number of primary THA cases has led to a corresponding rise in the frequency of revision surgeries, which are often more complex and challenging due to severe acetabular bone loss. In such cases, managing Paprosky type 3A and 3B defects requires precise implant design and advanced surgical techniques. Standard acetabular augments and anti-protrusio cages are commonly used, but they often fail to provide the necessary stability, leading to re-revision rates as high as 36% within 10 years. This case series explores the efficacy of custom-made 3D-printed acetabular augments and cages in managing severe acetabular bone loss during revision THA. This retrospective case series includes seven patients who underwent revision THA for Paprosky grade 3 acetabular bone loss between January 2023 and April 2024 at two high-volume tertiary care centers. The mean age of the patients was 45 years, with three males and four females included in the study. Pre-operative planning involved advanced imaging techniques, including 3D-computed tomography scans and custom virtual modeling, to design the acetabular components tailored to each patient's specific anatomical requirements.During the surgeries, custom-made 3D-printed titanium augments and cages were used. These implants were fabricated using in-house software, and the turnaround time from the decision to surgery was approximately 10 days. Post-operatively, the planned 3D model was superimposed on post-operative radiographs to assess implant placement accuracy. The Harris hip score at the final follow-up averaged 69.16, with no signs of implant loosening observed. Custom-made 3D-printed acetabular augments and cages offer a reliable and cost-effective solution for managing severe acetabular bone loss in revision THA. Despite the small sample size and short follow-up period, the results demonstrate the potential of these custom implants to improve outcomes in complex acetabular reconstructions. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings and establish long-term efficacy.

Clinical and functional outcomes of a modular fluted titanium stem in complex hip surgery with femoral bone loss

BackgroundThe tapered fluted titanium stem is a viable option for complex hip reconstruction. We therefore, evaluate the results of complex hip arthroplasty for femoral bone loss (Paprosky type IIIA to type IV femoral defect), using a modular fluted titanium stem. MethodsData for this retrospective study was collected from the medical records of the 2 participating orthopaedic units from December 2018 to December 2021. Twenty-seven patients who underwent reconstruction of femoral bone loss with a modular fluted titanium stem were included in this study. General, demographic and clinical data including patient's age, comorbidities, ambulatory status before and after surgery, blood transfusion, surgical complications, rehabilitation after surgery, length of stay in hospital (in days), readmission after surgery, implant details and mortality rate were recorded. Clinical evaluation was performed using the oxford hip score and 12-item short-form health survey (SF-12). Complications and survivorship were evaluated using Kaplan–Meier survival rate with 95 % confidence interval. ResultsThe mean age for the cohort was 60.14 ± 11.58 years, with mean follow-up of 3.2 years for the study. The median pre-operative OHS was 10 (8), which improved to 39 (12) and 41 (4) at 1 and 2-year postoperative follow-up, respectively (P < 0. 001). The quality of life measures (SF-12 scores) in both mental and physical components showed progressive improvement at 2 years follow-up with P- value < 0.001. A total of five patients (18.5 %) had postoperative complications, including deep venous thrombosis in one patient, dislocations in two patients and one patient each with superficial and deep infection. The implant survival rate was 100 % at mean follow-up of 3.2 years. ConclusionsProximal femur reconstruction with a modular fluted titanium stem restores mobility, improves the quality of life and reduces pain significantly. It can be considered as a good option as a salvage procedure.

Trabecular Metal Augments for the Management of Paprosky Type III Defects Without Pelvic Discontinuity: Average 11-Year Follow-Up in Cases with Previously Reported 4-Year Clinical Results

This retrospective case series aimed to assess the clinical and radiographic outcomes of revision total hip arthroplasty with trabecular metal (TM) augments associated with cementless TM acetabular components for the management of Paprosky type IIIA and IIIB defects without pelvic discontinuity. There were 83 hips (82 patients) enrolled. There were 53 patients who completed the clinical and radiological follow-up (64% of the total) who had a mean follow-up of 11 years (range, 7 to 16.6). There were seven patients who died during the follow-up period without undergoing further revision, and 23 were lost to follow-up. A Paprosky type IIIA defect was found in 42 hips, whereas a Paprosky type IIIB defect was present in 11 hips. We previously reported short-term outcomes for 55 hips that underwent acetabular reconstruction using TM cups associated with TM augments with a mean follow-up of 53.7 months. Here, we followed the clinical and radiological outcomes of the aforementioned patients and 28 more hips. We retrospectively collected the clinical and radiological data of all the patients operated on in our tertiary referral center between 2005 and2016. The average Harris Hip Score increased from 36.4 (range, 24 to 53) preoperatively to 87.4 (range, 63 to 100) at the last follow-up. The cumulative survival of the acetabular construct at 7 years of follow-up was 90.6% (95% confidence interval [CI]: 78.8 to 95.9) considering revision for any reason, and at 10 years of follow-up was 86.3% (95% CI: 73.4 to 93.2). The cumulative survival of the acetabular construct at 7 years of follow-up was 94.2% (95% CI: 83.2 to 98.1) considering revision for aseptic loosening, and at 10 years of follow-up was 92.1% (95% CI: 80.4 to 97). The use of TM cups and augments could be considered an effective management of Paprosky type III defects without pelvic discontinuity. The present technique provides an anatomical reconstruction of the defect with the restoration of the hip center of rotation associated with good clinical and radiographic outcomes in the midterm. Level IV, case series.

Treatment of patients with periprosthetic infection and management of Paprosky type 2C cavitary defects at the stage of articulating spacer installation

Introduction Due to the constant increase in the number of primary and revision hip arthroplasties, the incidence of complications has been also increasing. Periprosthetic joint infection (PJI) is the most common and dangerous complication in joint arthroplasty, including PJI with cavitary defects of the acetabulum (Paprosky type 2C).The purpose of the work was to demonstrate successful results of managing acetabular defects in patients with periprosthetic infection at the stage of installing an articulating spacer.Materials and methods The patients underwent surgical management of cavitary defects of the acetabulum with allobone plastic material at the stage of installation of an articulating spacer impregnated with antibacterial drugs. A clinical and functional assessment of the effectiveness of treatment of patients with PJI of the hip joint, who underwent bone grafting of acetabular defects at the first stage of two-stage revision arthroplasty, was carried out. Remission of the infectious process was assessed according to the ICM 2013 (International Consensus Meeting), and the function of the affected limb was assessed according to the HHS (Harris Hip Score).Results At a 6-month follow-up after implantation, there were no clinical and laboratory manifestations of PJI and radiological signs of instability of the implant components. Bone grafting was evaluated to be satisfactory; the function of the affected joint restored to 80–90 to HHS points. Remission of the infectious process according to ICM was achieved.Discussion Clinical cases studied demonstrate a positive result of treatin PJI with plastic surgery of cavitary defects of the acetabular bottom at the stage of articulating spacer installation. Filling acetabular defects at the sanitizing stage (implantation of a spacer) subsequently provides improvement of primary fixation and osseointegration of the acetabular component when converting the spacer to a permanent implant. This is due to an increase in the contact area of the acetabular component with bone tissue (native bone and remodeled allobone material).Conclusion The treatment of the first clinical case improved joint function from 24 to 85 HHS points, and in the second from 27 to 76 HHS points. The use of defect filling techniques enabled to stop the infection and improve functional results.

Use of morselized bone allograft in revision hip arthroplasty for massive acetabular defect: A systematic review and meta-analysis.

Many treatment options are available for the revision of large acetabular defects. Debate continues as to which technique is most effective. This meta-analysis aimed to determine the rates of failure of acetabular bone defects Paprosky type III or American Academy of Orthopaedic types III-IV treated with morselized allograft in association with cemented cup or cementless cup or reinforcement devices. The US National Library of Medicine (PubMed/MEDLINE), EMBASE and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to 1 April 2024 utilizing keywords pertinent to total hip arthroplasty (THA), acetabular impaction bone grafting and revision THA. The main outcome measure was the 9-year implant failure rate. Thirty-nine articles were eligible for inclusion in the current study. We found 41 treatment approaches that we grouped into three different treatment options: 1 = morselized allograft and cemented cup (10 studies); 2 =morselized allograft and cementless cup (nine studies); 3 = morselized allograft and device (22 studies). The overall implant failure rate was 2.1% (95% confidence interval [CI], 1.6%-2.8%) at a mean of 9.2 years. There was no significant difference in failure rates between different treatment options (1.6% [95% CI, 0.9%-2.6%]) for morselized allograft and cemented cup; 2.1% (95% CI, 1.4%-3.2%) for morselized allograft and cementless cup; 2.5% (95% CI, 1.7%-3.7%) for morselized allograft and device) between the three different types of treatment (heterogeneity between groups p = 0.351).It was determined that the number one cause of failure was aseptic loosening (80.5%), followed by infection (13.1%) and dislocation (6.4%). THA with reinforcement devices has a higher incidence of infection (3.6 vs. 0.7%, p = 0.001) and dislocation (1.4 vs. 0.6%, p = 0.010) than THA with a cemented cup. The use of morselized allograft in hip revision of large acetabular defects has low implant failure rates, independently of the associated type of implant. Reinforcement devices increase the risk of re-revision for infection and dislocation. Level III.

Reconstruction of severe acetabular defects (Paprosky type III A) in total hip arthroplasty using modular tantalum augments in combination with a cemented cup

PurposeAcetabular defect reconstruction can be a complex and challenging surgical procedure, with stable long-term fixation of the implants remaining the ultimate goal. The purpose of this study was (1) to evaluate the radiological and clinical outcome of complex acetabular reconstruction surgery with the use of modular tantalum TM augments in combination with cemented revision cups; (2) to investigate blood tantalum concentrations in these patients; and (3) to report complications and mechanisms of failure related to this procedure at mid-term follow-up (mean 4.5 years).MethodsWe retrospectively reviewed 29 patients (29 hips) with severe acetabular bone loss (Paprosky type III A) reconstructed using a modular tantalum TM augment in combination with a cemented cup. We evaluated the implant survival and the radiological and clinical outcomes after a mean follow-up of 4.5 years (SD 2.2; range 8.4 – 2.1 years) using patient reported outcome scores (PROMs). Blood samples were analysed regarding tantalum concentration and compared with a control group.ResultsThe cumulative survival rate at 4.5 years with the endpoint “revision of the acetabular component for any reason” was 96.2% (95% Confidence Interval 75.7–99.5). The PROMs improved significantly up to the latest follow-up, and radiographic data showed only one patient with signs of initial implant migration with a broken screw and a change of the position of the augment and the cup. Mean blood tantalum concentrations were significantly higher in the study group (0.16 µg/L) compared to the control group (0.002 µg/L) (P < 0.001).ConclusionsThis study has demonstrated good mid-term (mean 4.5 years) clinical and radiological outcomes of modular tantalum TM augments in combination with a cemented cup for the reconstruction of major acetabular defects. Mean blood tantalum concentrations were increased in patients with stable tantalum implants compared to healthy controls.

Reliability and validity of the Paprosky classification for acetabular bone loss based on level of orthopedic training.

Reliability and validity of the Paprosky classification for acetabular bone loss have been debated. Additionally, the relationship between surgeon training level and Paprosky classification accuracy/treatment selection is poorly defined. This study aimed to: (1) evaluate the validity of preoperative Paprosky classification/treatment selection compared to intraoperative classification/treatment selection and (2) evaluate the relationship between training level and intra-rater and inter-rater reliability of preoperative classification and treatment choice. Seventy-four patients with intraoperative Paprosky types [I (N = 24), II (N = 27), III (N = 23)] were selected. Six raters (Residents (N = 2), Fellows (N = 2), Attendings (N = 2)) independently provided Paprosky classification and treatment using preoperative radiographs. Graders reviewed images twice, 14 days apart. Cohen's Kappa was calculated for (1) inter-rater agreement of Paprosky classification/treatment by training level (2), intra-rater reliability, (3) preoperative and intraoperative classification agreement, and (4) preoperative treatment selection and actual treatment performed. Inter-rater agreement between raters of the same training level was moderate (K range = 0.42-0.50), and mostly poor for treatment selection (K range = 0.02-0.44). Intra-rater agreement ranged from fair to good (K range = 0.40-0.73). Agreement between preoperative and intraoperative classifications was fair (K range = 0.25-0.36). Agreement between preoperative treatment selections and actual treatments was fair (K range = 0.21-0.39). Inter-rater reliability of Paprosky classification was poor to moderate for all training levels. Preoperative Paprosky classification showed fair agreement with intraoperative Paprosky grading. Treatment selections based on preoperative radiographs had fair agreement with actual treatments. Further research should investigate the role of advanced imaging and alternative classifications in evaluation of acetabular bone loss.

Mid-Term Clinical and Radiographic Results of Complex Hip Revision Arthroplasty Based on 3D Life-Sized Model: A Prospective Case Series.

Background: The pre-operative three-dimensional (3D) assessment of acetabular bone defects may not be evaluated properly with conventional radiographic and computed tomography images. This paper reports mid-term clinical and radiographic outcomes of complex revision total hip arthroplasty (r-THA) based on a 3D life-sized printed model. Methods: Patients who underwent r-THA for septic or aseptic acetabular loosening with acetabular defects Paprosky types IIc, IIIa, and IIIb between 2019 and 2021 were included. The outcomes of the study were to determine clinical and radiographic assessment outcomes at the time of the last follow-up. Results: 25 patients with mean age of 62.9 ± 10.8 (18-83) years old were included. The mean Harris hip score improved from 34.8 ± 8.1 pre-operative to 81.6 ± 10.4 points (p < 0.001). The mean visual analog scale decreased from 6.7 ± 1.4 points pre-operative to 2.4 ± 1.0 points (p < 0.001). The mean limb length discrepancy improved from -2.0 ± 1.2 cm pre-operative to -0.6 ± 0.6 cm (p < 0.001). The mean vertical position of the center of rotation (COR) changed from 3.5 ± 1.7 cm pre-operative to 2.0 ± 0.7 cm (p < 0.05). The mean horizontal COR changed from 3.9 ± 1.5 cm pre-operative to 3.2 ± 0.5 cm (p < 0.05). The mean acetabular component abduction angle changed from 59.7° ± 29.6° pre-operative to 46° ± 3.9 (p < 0.05). Conclusions: A three-dimensional-printed model provides an effective connection between the pre-operative bone defects' evaluation and the intraoperative findings, enabling surgeons to select optimal surgical strategies.

Survival analysis of 3D printed acetabular implants in revision total hip arthroplasty associated with severe pelvic discontinuities.

Surgeons still face difficulties when performing aseptic acetabular revision on patients with extensive defects. Advances in three-dimensional printing technology (3DP) have afforded to the surgeons to create a patient-specific implant matching the morphology and topography of the defect. The aim of the current research was to determine the survivorship in the treatment of acetabular bone defects with pelvic discontinuity (PD). In order to reconstruct Paprosky type III defects with PD, twenty-three patients underwent revision total hip arthroplasty (THA) utilizing 3D-printed implants (Mobelife). The primary outcomes were the implant-associated failure rate correlated with survivorship. As secondary variables, complications and the effect of age, sex, comorbidities, history of infections and the presence of other lower limb arthroplasties on a new revision were analyzed. Patients were followed out to a mean of 67.22 ± 39.44 months (range, 0.9-127 months). Mobelife implant mean survival was 102.57 ± 9.90 months (95% CI 83.17-121.96). The cohort's implant one-year survival rate was 87%; at ten years, it dropped to 78.3%. There were four revisions: three due to periprosthetic joint infection (PJI) and one case due to aseptic loosening. Cox regression analysis did not identify any variable as predictor of failure. The use of 3DP patient-specific acetabular components has shown encouraging results and it is a viable treatment option for addressing acetabular defects with combined PD in aseptic THA revision.

The application and effect of bispherical augment in acetabular defects reconstruction

Objective: To evaluate the clinical effect of bispherical augment in acetabular defects reconstruction in hip revision. Methods: This is a retrospective case series study. A retrospective analysis of 119 patients (124 hips) patients who underwent hip revision surgery and reconstructed with bispherical augment for acetabular bone defects from January 2019 to December 2023 was performed. There were 57 males (58 hips) and 62 females (66 hips), aged (65.0±11.8) years (range:40 to 102 years). The body mass index was (23.9±3.5) kg/m2 (range:16.1 to 32.2 kg/m2). Acetabular bone defects were typed as follows: 2 hips in Paprosky type ⅡA, 29 hips in type ⅡB, 34 hips in type ⅡC, 31 hips in type ⅢA, and 28 hips in type ⅢB, of which 9 patients (9 hips) were combined with pelvic discontinuity. Differences in Harris hip score (HHS) and lower limb discrepancy (LLD) were compared between preoperatively and final follow-up. The height of the hip center of rotation and the horizontal distance from the center of rotation to the teardrop were measured by radiographs before and after surgery, and prothesis stability and the occurrence of postoperative complications were evaluated. Data were compared using the paired sample t test. Results: All patients successfully completed the operation. The operation time was (167.0±53.4) minutes (range:90 to 380 minutes) and the intraoperative bleeding was (345.3±124.2) ml (range:100 to 1 200 ml). The height of the hip center of rotation decreased from (39.7±13.0) mm preoperatively to (21.8±7.1) mm postoperatively and the horizontal distance from the center of rotation to the teardrop increased from (34.0±10.1) mm preoperatively to (38.5±5.9) mm postoperatively, and the differences were statistically significant (t=15.859, P<0.01; t=5.266,P<0.01). All the patients were followed up for (26.1±15.4) months (range:6 to 60 months). At the last follow-up, HHS improved from (35.2±10.0) points preoperatively to (85.5±9.5) points, and the difference was statistically significant (t=50.723,P<0.01). LLD decreased from (2.1±1.1) cm preoperatively to (0.5±0.5) cm, and the difference was statistically significant (t=13.767, P<0.01). All acetabular components were stable and free of displacement on imaging during follow-up. Three patients suffered dislocation and received closed reduction, all prosthesis were in good position during follow-up. No dislocation, loosening, fracture, recurrence of infection and vascular nerve injury occurred in other patients. Conclusion: Bispherical augment can effectively reconstruct acetabular bone defects, restore the hip center of rotation, and improve hip joint function scores at short and mid-term follow-up.

RECONSTRUCTION OF PAPROSKY TYPE III ACETABULAR BONE DEFECTS IN REVISION HIP ARTHROPLASTY USING A COMBINATION OF CAGE AND MORSELIZED ALLOGRAFTS

The management of severe acetabular bone defects poses a complex challenge in revision hip arthroplasty. Although biological fixation materials are currently dominant, cage has played an important role in complex acetabular revision in the past decades, especially when a biological prosthesis is not available. The purpose of this study is to report the long-term clinical and radiographic results of Paprosky type Ⅲ acetabular bone defects revised with cage and morselized allografts.We retrospectively analyzed 45 patients who underwent revision hip arthroplasty with cage and morselized allografts between January 2007 and January 2019. Forty-three patients were followed up. There were 19 Paprosky type IIIA bone defect patients and 24 Paprosky type IIIB bone defect patients and 7 patients of the 24 were also with pelvic discontinuity. Clinical assessment included Harris Hip Score (HHS) and Short Form-12 (SF-12). Radiographic assessment included cage stability, allografts incorporation, and center of rotation.All patients were followed up with a mean follow-up of 10.6 years, HHS and SF-12 improved significantly at last follow-up in comparison to the preoperative. There were 2 re-revisions, one at 5 years after surgery, another at 13.6 years after surgery. Two patients had nonprogressive radiolucency in zone III and the junction of zone II and zone III at the bone implant interface. Allografts of 40 (93%) cases incorporated fully.The combination of cage and morselized allograft is an alternative option for acetabular revision with Paprosky type III bone defects with satisfactory long-term follow-up results.

Medium- and long-term effectiveness of hip revision with SL-PLUS MIA stem in patients with Paprosky type Ⅰ- Ⅲ femoral bone defect

To investigate the medium- and long-term effectiveness of hip revision with SL-PLUS MIA stem in patients with Paprosky typeⅠ-Ⅲ femoral bone defect. Between June 2012 and December 2018, 44 patients with Paprosky typeⅠ-Ⅲ femoral bone defect received hip revision using SL-PLUS MIA stem. There were 28 males and 16 females, with an average age of 57.7 years (range, 31-76 years). Indications for revision comprised aseptic loosening (27 cases) and periprosthetic joint infection (17 cases). The Harris hip scores were 54 (48, 60) and 43 (37, 52) in patients with aseptic loosening and periprosthetic joint infection, respectively. The preoperative femoral bone defects were identified as Paprosky type Ⅰ in 32 cases, type Ⅱ in 9 cases, type ⅢA in 2 cases, and type ⅢB in 1 case. Operation time and intraoperative blood transfusion volume were recorded. During follow-up after operation, the hip joint function were evaluated by Harris hip score and X-ray films, the femoral stem survival was analyzed, and the surgical related complications were recorded. The operation time of infected patients was 95-215 minutes, with an average of 125.0 minutes. The intraoperative blood transfusion volume was 400-1 800 mL, with an average of 790.0 mL. The operation time of patients with aseptic loosening was 70-200 minutes, with an average of 121.0 minutes. The intraoperative blood transfusion volume was 400-1 400 mL, with an average of 721.7 mL. All patients were followed up 5.3-10.0 years (mean, 7.4 years). At last follow-up, the Harris hip scores were 88 (85, 90) and 85 (80, 88) in patients with aseptic loosening and periprosthetic joint infection, respectively, both of which were significantly higher than those before operation ( P<0.05). Radiological examination results showed that the distal end of the newly implanted femoral stem did not cross the distal end of the original prosthesis in 25 cases, and all femoral stems obtained bone fixation. Two cases experienced femoral stem subsidence and 1 case had a translucent line on the lateral side of the proximal femoral stem. When aseptic loosening was defined as the end event, the 10-year survival rate of the SL-PLUS MIA stem was 100%. When treatment failure due to any reason was defined as the end event, the survival time of the prosthesis was (111.70±3.66) months, and the 7-year survival rate was 95.5%. The 7-year survival rates were 94.1% and 96.3% in patients with aseptic loosening and periprosthetic joint infection, respectively. The incidence of postoperative complications was 9.1% (4/44), among which the prosthesis related complications were 4.5% (2/44), 1 case of dislocation and 1 case of infection recurrence. Hip revision with SL-PLUS MIA stem has the advantages of simple operation and few postoperative complications in the patients with Paprosky type Ⅰ-Ⅲ femoral bone defect, and the medium- and long-term effectiveness is reliable.

Bone remodeling after revision total hip arthroplasty for large acetabular defects.

Large acetabular bone defects are challenging in hip revision surgery. Clinical assessment is crucial to evaluate modern technologies in surgical reconstruction. We aimed to better understand the bone remodeling that occurs following acetabular reconstruction. Our objectives were: (1) To characterize changes in the shape of the pelvis by studying sequential computed tomography (CT) scans collected immediately and 1-year postoperatively and (2) to identify which part of the pelvis is most susceptible to remodeling. We used the CT scans taken at two timepoints, of 24 patients with acetabular bone defects classified as Paprosky IIIB, treated with three-dimensional (3D)-printed custom-made acetabular implants. Segmented 3D models of the bony pelvis were co-registered using three different techniques. A global co-registration of the full pelvis was conducted, followed by the co-registration of the innominate bone and then ilium only, on the ipsilateral reconstructed side. The relative movements of the ilium, ischium, and pubis were analyzed from visual inspection and using co-registration metrics (root mean square error and intersection over union). No bone remodeling was found in 14/24 patients (58%). The co-registration of the innominate bone indicated bone remodeling in five cases (21%), while the remaining five cases (21%) presented remodeling in the global co-registration but not the innominate bone co-registration, suggestive of changes occurring at the sacroiliac joint. Changes in the pelvic shape were greatest at the pubis and ischium. Bone remodeling may occur in complex cases of Paprosky type IIIB defects, after acetabular reconstruction (occurrence of 21%, 5/24 cases). Surgeons and engineers should consider this when monitoring implant migration.

3D-printed Personalized Porous Acetabular Component to Reconstruct Extensive Acetabular Bone Defects in Primary Hip Arthroplasty.

Management of extensive acetabular bone defects in total hip arthroplasty (THA) remains challenging. This study aims to investigate the feasibility and preliminary outcomes of 3D-printed personalized porous acetabular components for the reconstruction of acetabular defects in primary THA. This retrospective study involved seven patients who received 3D-printed acetabular components in primary THA between July 2018 and March 2021. Preoperatively, acetabular bone defects were evaluated by referencing the Paprosky classification. There were two "Paprosky type IIIA" defects and five "Paprosky type IIIB" defects. The acetabular components were custom-made for each patient to reconstruct the extensive acetabular defects. The hip function was assessed according to the Harris hip score (HHS). Clinical and radiographic outcomes were assessed. The average follow-up period was 40 months, ranging from 26 to 57 months. There were no patients lost to follow-up. The HHS improved from 44 (range: 33-53) before the operation to 88 (range: 79-93) at the final follow-up. Postoperative X-rays showed that the 3D-printed personalized components were properly fitted with the acetabulum. The average center of rotation (COR) discrepancy was 2.3 mm horizontally and 2.1 mm vertically, respectively. Tomosynthesis-Shimadzu metal artifact reduction technology images showed that the implant was in close contact with the host bone. Moreover, no complications were observed during the follow-up period, including loosening, dislocation, or component protrusion. The implantation of 3D-printed personalized acetabular components showed accurate reconstruction, stable mechanical support, and favorable function at short-term follow-up. This may be a viable alternative method for reconstructing extensive acetabular defects in THA.

Outcomes of a Double-Cup Construct to Treat Paprosky 3A and 3B Acetabular Defects at a Mean of 39 Months

BackgroundModular reconstruction systems based on porous tantalum (PT) prosthetic components have been increasingly used for the treatment of complex acetabular bone defects in revision total hip arthroplasty. We report a novel technique that applies a revision cup as a “super-augment” to form a “double-cup” construct for Paprosky type III defects. MethodsA retrospective review was conducted on revision total hip arthroplasty cases, comparing those treated with double-cup constructs (DC group, n = 48) to those treated with PT shells and augments (PT group, n = 48). All procedures were performed at the same institute between 2017 and 2022. Clinical outcome evaluation utilized the Harris Hip Score, Oxford Hip Score, and the 36-Item Short Form Survey. Preoperative and postoperative radiographic assessments measured hip center of rotation (COR) position and leg length discrepancy. Additionally, postoperative complications and implant survivorship were monitored during the follow-up period. ResultsThe clinical outcomes improved substantially in both groups, which showed no significant difference in the Harris Hip Score (P = .786), the Oxford Hip Score (P = .570), and the 36-Item Short Form Survey (P = .691). Compared to the PT group, the reconstruction COR was significantly closer to the anatomic COR (vertical distance: 2.630 versus 7.355 mm, P = .0034; horizontal distance: 1.881 versus −6.413 mm, P < .0001) in Paprosky 3B type defects. Additionally, postoperative leg length discrepancy was less in the DC group (−8.252 versus −1.821 mm, P = .0008). Dislocation was the main complication in the DC group, and only 1 patient received re-revision due to repeated dislocation. The cumulative survival rate of the DC group (100%; 95% confidence interval 100) was better than the PT group (83.4%; 95% confidence interval 70.5 to 98.6) when re-revisions for aseptic loosening were the endpoint (P = .046). ConclusionsThe DC is a reliable revision technique for the reconstruction of Paprosky type III bone defects. Although dislocation remains challenging, the biomechanically superior restoration achieved by this technique lowers the risk of aseptic loosening.

Custom Triflange Acetabular Implants for Complex Hip Revisions: A Case Series.

Revision total hip arthroplasty (THA) presents a formidable challenge when addressing extensive acetabular defects, particularly in severe cases classified under Paprosky types 3A and 3B and American Academy of Orthopaedic Surgeons types 3 and 4. Traditional methods often fall short, prompting the potential use of custom triflange acetabular components or patient-specific acetabular implants (PSAIs). These implants are specifically designed to conform to an individual's anatomy, aiming to enhance defect reconstruction and pelvic stabilization. This case series describes the utilization of advanced 3-dimensional printing and rapid prototyping technologies to construct customized acetabular components, which can be instrumental in enabling precise preoperative planning and surgical execution for these difficult acetabular cases and potentially leading to improved surgical outcomes.

Can a reconstruction algorithm in major acetabular bone loss be successful in revision hip arthroplasty?

The aims of this study were to determine the success of a reconstruction algorithm used in major acetabular bone loss, and to further define the indications for custom-made implants in major acetabular bone loss. We reviewed a consecutive series of Paprosky type III acetabular defects treated according to a reconstruction algorithm. IIIA defects were planned to use a superior augment and hemispherical acetabular component. IIIB defects were planned to receive either a hemispherical acetabular component plus augments, a cup-cage reconstruction, or a custom-made implant. We used national digital health records and registry reports to identify any reoperation or re-revision procedure and Oxford Hip Score (OHS) for patient-reported outcomes. Implant survival was determined via Kaplan-Meier analysis. A total of 105 procedures were carried out in 100 patients (five bilateral) with a mean age of 73 years (42 to 94). In the IIIA defects treated, 72.0% (36 of 50) required a porous metal augment; the remaining 14 patients were treated with a hemispherical acetabular component alone. In the IIIB defects, 63.6% (35 of 55) underwent reconstruction as planned with 20 patients who actually required a hemispherical acetabular component alone. At mean follow-up of 7.6 years, survival was 94.3% (95% confidence interval 97.4 to 88.1) for all-cause revision and the overall dislocation rate was 3.8% (4 of 105). There was no difference observed in survival between type IIIA and type IIIB defects and whether a hemispherical implant alone was used for the reconstruction or not. The mean gain in OHS was 16 points. Custom-made implants were only used in six cases, in patients with either a mega-defect in which the anteroposterior diameter > 80 mm, complex pelvic discontinuity, and massive bone loss in a small pelvis. Our findings suggest that a reconstruction algorithm can provide a successful approach to reconstruction in major acetabular bone loss. The use of custom implants has been defined in this series and accounts for < 5% of cases.

AAHKS Surgical Techniques & Technologies Award: Inferior Screw Fixation Decreases Acetabular Component Failure Following Revision Total Hip Arthroplasty

BackgroundAdjunctive screw fixation has been shown to be reliable in achieving acetabular component stability in revision total hip arthroplasty (THA). The purpose of this study was to assess the effect of inferior screw placement on acetabular component failure following revision THA. We hypothesized that inferior screw fixation would decrease acetabular failure rates. MethodsWe reviewed 250 patients who had Paprosky Type II or III defects who underwent acetabular revision between 2001 and 2021 across three institutions. Demographic factors, the number of screws, location of screw placement (superior versus inferior), use of augments and/or cup-cage constructs, Paprosky classification, and presence of discontinuity were documented. Multivariate regression was performed to identify the independent effect of inferior screw fixation on the primary outcome of aseptic rerevision of the acetabular component. ResultsAt a mean follow-up of 53.4 months (range, 12 to 261), 16 patients (6.4%) required re-revision for acetabular loosening. There were 140 patients (56.0%) who had inferior screw fixation, all of whom did not have neurovascular complications during screw placement. Patients who had inferior screws had a lower rate of acetabular rerevision than those who only had superior screw fixation (2.1 versus 11.8%, P = .0030). Multivariate regression demonstrates that inferior screw fixation decreased the likelihood of rerevision for acetabular loosening when compared to superior screw fixation alone (odds ratio: 0.1, confidence interval: 0.03 to 0.5; P = .0071). No other risk factors were identified. ConclusionsInferior screw fixation is a safe and reliable technique to reduce acetabular component failure following revision THA in cases of severe acetabular bone loss.