Treatment of Hip Osteoarthritis with Severe Acetabular Bone Defects by Total Hip Arthroplasty Using the Restoration GAP II Reinforcement Ring: A Case Report

To evaluate the medium-term clinical results of reconstruction of the severe acetabular bone defect by using metal mesh and impaction bone grafting (IBG) technique, as well as to emphasize the importance of Paprosky acetabular bone defect classification system in assessing the severity of bone defect and to analyse the failure reasons. Between December 1998 and December 2007, 67 total hip arthroplasty (THA) revisions were made by using IBG technique to reconstruct severe acetabular bone defects combining with metal mesh or meta mesh cup on 63 patients. All the defects were combined defect (AAOS Type 3). There were 20 Paprosky II B defects in 19 patients, 28 Paprosky II C defects in 29 patients and 13 Paprosky II A defects in 12 patients. Regular follow-ups, involving the assessments of Harris hip scoring system, clinical efficacy, imaging and complications, were subsequently made. Sixty-one hips in 58 patients gained an average of 63 months (8-107) follow-up. Harris hip score increased from an average of 41.7 points (21-52) preoperatively to an average of 89.2 points (81-98) at the last follow-up, with an excellent and good rate of 93%. Radiographically, there were no loosening cases excluding the 3 dislocated polyethylene cups from the metal mesh cups. One case was failed to reconstruction the height of normal hip center, in which metal mesh cup was used for enforce the medial wall. Dislocations occurred in 3 hips, 1 of these patients required an open reduction and the other 2 dislocations only need close reduction. Postoperative infection rate was 1.6% (1 case), two stage revision with another IBG procedure succeeded in this patient. IBG combing with metal mesh for reconstruction of severe acetabular bone defect is an ideal technology. Paprosky acetabular bone defect classification system is very important in IBG procedure besides AAOS acetabular bone defect classification system to evaluate the severity of bone defect and to compare the outcomes between different authors. The use of metal mesh cup should be avoided to enforce acetabular medial wall in patients with severe acetabular bone defect.

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.

ObjectiveIn revision total hip arthroplasty (THA), reconstruction of severe acetabular bone defect continues to be problematic for orthopedic surgeons. This study reports the mid‐ to long‐term survivorship, radiological outcomes, and complications of impaction bone grafting (IBG) and metal mesh with a cemented acetabular component in the reconstruction of severe acetabular bone defects in revision THA.MethodsThis retrospective consecutive study included 26 patients (29 hips: type II B, four; type II C, three; type III A, 10; and type III B, 12) who underwent revision THA, which was performed using IBG and metal mesh, between 2007 and 2014 in our institution. All patients were followed up regularly for clinical and radiographical assessments. Migration and loosening of prosthesis graft integration and complications were observed and analyzed. Survival analysis was performed using a Kaplan–Meier survival analysis.ResultsAt the time of revision, 75.9% of the hips (22 hips) were classified as type III bone defects. The average follow‐up period was 9.4 ± 2.8 (range, 2.4–14.0) years. Of the 29 hips, four hips (13.8%) were assessed as clinical failures; at the last follow‐up, two had undergone re‐revision THA, and two had not been scheduled for re‐revision THA despite radiological failure of the acetabular component. Among them, three clinical failures (10.3%) were due to aseptic loosening, and one (3.4%) was due to infection. Radiographic evaluation showed bone graft integration in all hips during the follow‐up. The Kaplan–Meier survivorship analysis revealed an acetabular reconstruction survival rate of 86.5% (95% confidence interval, 61.4%–95.7%) at 10 years.ConclusionIBG and metal mesh with a cemented acetabular component for revision THA is an effective technique for treating severe acetabular bone defects, with effective mid‐ to long‐term outcomes due to the solid reconstruction of the acetabular bone defect and restoration of the hip rotation center.

In cementless revision total hip arthroplasty (THA), achieving initial implant stability and maximising host bone contact is key to the success of reconstruction. Porous tantalum acetabular shells may represent an improvement from conventional porous coated uncemented cups in revision acetabular reconstruction associated with severe acetabular bone defects. We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects done with a hemispheric, tantalum acetabular shell and multiple supplementary screws. At a mean follow-up of 40 (24-51) months, one acetabular shell had been revised in a patient with a Paprosky 3B defect. Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent early clinical and radiographic results and warrants further evaluation in revision acetabular reconstruction associated with severe acetabular bone defects.

In cementless revision total hip arthroplasty (THA), achieving initial implant stability and maximising host bone contact is key to the success of reconstruction. Porous tantalum acetabular shells may represent an improvement from conventional porous coated uncemented cups in revision acetabular reconstruction associated with severe acetabular bone defects. We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects done with a hemispheric, tantalum acetabular shell and multiple supplementary screws. At a mean follow-up of 40 (24-51) months, one acetabular shell had been revised in a patient with a Paprosky 3B defect. Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent early clinical and radiographic results and warrants further evaluation in revision acetabular reconstruction associated with severe acetabular bone defects.

Short-term clinical efficacy of three dimension printed titanium augments for the reconstruction of acetabular bone defects in revision total hip arthroplasty

ObjectiveRevision of total hip arthroplasty for patients with severe acetabular bone defects is challenging. This study aims to report the minimum 2 years outcome of the iliac extended fixation technique in patients with Paprosky type III acetabular defects.MethodsFifty‐seven revision total hip arthroplasty patients were retrospectively reviewed who underwent reconstruction with the concept of iliac extended fixation from 2014 to 2017 in our hospital. We proposed a new concept of “iliac extended fixation” in revision total hip arthroplasty as fixation extending superiorly 2 cm beyond the original acetabular rim with porous metal augments, which was further classified into intracavitary and extracavitary fixation. Patients were assessed using the Harris Hip Score and the Western Ontario and McMaster Universities Osteoarthritis Index Score. Radiographs and patient‐reported satisfaction were assessed.ResultsAt an average follow‐up of 63 months (range 25–88 months), the postoperative Harris Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly improved at the last follow‐up (p < 0.001). The center of rotation was significantly improved (p < 0.05). Fifty‐three (93.0%) patients were satisfied with the outcome. The extracavitary iliac extended fixation group had higher rate of osteointegration in zone 1A (the superior lateral zone) than the intracavitary iliac extended fixation group (82.3% vs 55.0%, p = 0.015), and significantly more horizontal screws fixation (5.1 ± 24.7° vs 42.3 ± 36.8°, p < 0.001).ConclusionIntracavitary and extracavitary iliac extended fixation with porous metal augments and cementless cups are effective in reconstructing severe superior acetabular bone defects. The difference in screw direction might reflect the different biomechanics of augment fixation.

Severe acetabular bone defect is challenging in revision hip arthroplasty. In the present study, we aimed to present new treatment options with the 3D printing technique and analyze the clinical and radiographic outcomes of 3D-printed titanium implants for the treatment of severe acetabular bone defects in revision hip arthroplasty. A total of 35 patients with Paprosky type 3 bone defect and pelvic discontinuity (PD), who underwent hip revisions using 3D-printed titanium implants between 2016 and 2019 at our institution, were retrospectively reviewed. Patient-specific 3D-printed titanium augments and shells (strategy A) were used in 22 type 3A and two type 3B patients. Custom 3D-printed flanged components (strategy B) were used in 11 type 3B patients, including five PD. The clinical outcomes were evaluated with the Harris hip score (HHS). In addition, radiographic results were analyzed by the hip centre of rotation (V-COR and H-COR), implant failure, and survivorship. The mean follow-up was 41.5 months (range, 16-62). The HHS was improved from 47.8 ± 8.2 pre-operatively to 78.1 ± 10.1 at oneyear follow-up and 86.4 ± 5.1 at the last follow-up (p < 0.01). Post-operative V-COR and H-COR of the operated side were 20.8 ± 2.0 mm and 30.2 ± 1.6 mm compared with 51.4 ± 4.1 mm and 33.9 ± 9.0 mm pre-operatively (p < 0.01). The complications included one dislocation and one partial palsy of the sciatic nerve. At the latest follow-up, no radiological component loosening or screw breakage was present. 3D-printed titanium implants showed satisfactory short- and mid-term clinical and radiographic outcomes. It was an effective therapeutic regimen with a low rate of complications, providing a patient-specific and reliable strategy for the severe acetabular bone defect in revision hip arthroplasty.

PurposeDuring revision total hip arthroplasty (THA), severe acetabular bone defects are usually treated with bone allograft combined with a metal cage or ring. The purpose of this study was to assess clinical and radiological outcomes after acetabular reconstruction with supercritical CO2 (Supercrit®) bone allografts.MethodsPatients treated for acetabular reconstruction with Supercrit® allograft at [redacted] between 2005 and 2010 were included in this retrospective study. Patients were reviewed annually, and adverse event, clinical (Postel Merle d’Aubigné (PMA) score), and radiographic data were collected. Implant migration was measured on standard X-rays.ResultsFifty-one patients, average age 66 years [range 39–90], were treated with 39 Müller reinforcement rings, 11 Bürch-Schneider rings, and one Link® ring via a posterolateral approach in most cases. Acetabular reconstruction required an average of 1.2 femoral head allografts. Full weight-bearing occurred on postoperative day two or at week six in cases of bipolar revision via a complementary transfemoral approach. Average follow-up was 148 months. The PMA score improved significantly from baseline. The survival rate at 12 years with revision for any reason was 91.5% (95% CI 83–98%). The dislocation rate was 17%, but no dislocations occurred in patients receiving a dual mobility cup cemented in the reinforcement ring. Implants were stable with no cage or screw fractures, except in three patients with reconstruction failure.ConclusionSupercrit®-processed allogeneic bone combined with metal rings represents a suitable and satisfactory solution for acetabular reconstruction. Postoperative dislocation risk seems to be reduced by cementing a dual mobility cup in the metal ring.

Revision total hip arthroplasty (rTHA) presents significant challenges, particularly in patients with severe acetabular bone defects. Traditional treatment options often fall short, leading to the emergence of custom-made 3D-printed acetabular implants. Accurate assessment of implant positioning is crucial for ensuring optimal postoperative outcomes and for providing feedback to the surgical team. This single-center, retrospective cohort study evaluates the accuracy of standard 2D radiographs versus 3D CT scans in assessing the positioning of these implants, aiming to determine if 2D imaging could serve as a viable alternative for the postoperative evaluation. We analyzed the implant positions of seven rTHA patients with severe acetabular defects (Paprosky ≥ Type IIIA) using an alignment technique that integrates postoperative 2D radiographs with preoperative CT plans. Two independent investigators, one inexperienced and one experienced, measured the positioning accuracy with both imaging modalities. Measurements included translational shifts from the preoperatively templated implant position in the craniocaudal (CC), lateromedial (LM), and ventrodorsal (VD) directions, as well as rotational differences in anteversion (AV) and inclination (INCL). The study demonstrated that 2D radiographs, when aligned with preoperative CT data, could accurately assess implant positions with precision nearly comparable to that of 3D CT scans. Observed deviations were 1.4 mm and 2.7 mm in CC and LM directions, respectively, and 3.6° in AV and 0.7° in INCL using 2D imaging, all within clinically acceptable ranges. For 3D CT assessments, mean interobserver variability was up to 0.9 mm for translational shifts and 1.4° for rotation, while for 2D alignment, observer differences were 1.4 mm and 3.2° for translation and rotation, respectively. Comparative analysis of mean results from both investigators, across all dimensions (CC, LM, AV, and INCL) for 2D and 3D matching, showed no significant differences. In conclusion, conventional anteroposterior 2D radiographs of the pelvis can sufficiently determine the positioning of custom-made acetabular implants in rTHA. This suggests that 2D radiography is a viable alternative to 3D CT scans, potentially enhancing the implementation and quality control of advanced implant technologies.

To investigate the mid-term clinical efficacy of two acetabular revision methods in the treatment of severe Paprosky type Ⅲ acetabular bone defects. Clinical data of patients with severe acetabular defects who underwent surgical treatment were collected from July 2012 to March 2019,including 8 males and 11 females,all belong to Paprosky type Ⅲand underwent unilateral hip joint revision;12 cases(Group A) underwent revision using tantalum metal augment combined with porous biological tantalum cup,and 7 cases(Group B) underwent revision using titanium mesh compression bone grafting combined with cement prosthesis. Record the patient's surgical times,bleeding volumes,and complications,evaluate preoperative and postoperative X-rays as well as Harris scores. The average surgical time and intraoperative blood loss in Group A were (135.00±20.23) min and (828.57±213.81) mL,respectively. The Group B were(162.86±16.07) min and (1557.14±439.16) mL,respectively. The difference between two groups was statistically significant(P<0.05). The follow-up period ranged from 2 to 12 years. At the end of the follow-up,the Harris score in Group A increased from (36.25±6.88) scores to(82.67±7.16) scores (P<0.05);the Harris score in Group B increased from (33.29±5.22) scores to (79.29±5.62) scores (P<0.05). Among all patients,only 1 case had postoperative periprosthetic fracture,3 cases had lower limb venous thrombosis,and the rest had no neurovascular injury,infection,or early prosthesis loosening. the two acetabular revision methods can achieve satisfactory mid-term clinical efficacy in the treatment of Paprosky type Ⅲ severe acetabular bone defects.

56 patients with severe acetabular bone defects with or without pelvic discontinuity were included. In the TCA group 31 patients and 25 in the 3D group with a minimum follow-up of 2 years were included. The main indication for revision surgery with acetabular bone defect was aseptic loosening in both groups. The mean follow-up was 57.21 ± 28.81 months. Implant survival rates were 90.32% in the TCA group and 100% in the 3D (P = 0.24). Functional outcomes improved in both groups based on the Merle D'Aubigné & Postel score, with greater improvement in the 3D group (9.24 ± 3.23 vs. 6.55 ± 2.59 points, P = 0.001). Pain levels improved equally in both groups. Surgical time was shorter in the 3D group (108 ± 34.5 vs. 129 ± 43.4 minutes, P = 0.047).There were no significant differences in reoperation rate, transfusion need, hospital stay, or mortality. Tantalum metal cups and augments and custom-made 3D-printed trabecular titanium implants demonstrated an excellent survival rate in the management of severe acetabular bone defects. The group of patients operated on with custom 3D-printed implants had better postoperative functional outcomes and a shorter surgical time.

Severe acetabular bone defects can pose challenges in revision total hip replacement. The use of structural allografts and various sizes of grain allografts has been proposed as an alternative surgical technique for treating Paprosky type 3 acetabular defects. This study aimed to evaluate the long-term outcomes and potential complications associated with this approach. A retrospective review was performed on 102 hip reconstructions in patients with major acetabular bone loss, including 81 cases of type 3A and 21 cases of type 3B according to Paprosky's classification. Surgical procedures involved the use of structural allografts and various sizes of grain allografts in both reinforcement ring group and cementless cups group. At a mean follow-up of 82.75 months, 76% of hips had no complications, while The others experienced pain changes in the cup position, post-operative dislocations, and infections. The mean pre-operative Modified Harris Hip Score improved in both groups at the last follow-up. The use of structural allografts and various sizes of grain allografts for treating type 3 acetabular defects in revision total hip replacement showed promising long-term outcomes and a low rate of complications. Level of Evidence IV; Retrospective Case Series.

We analysed data from 155 revisions of identical cementless hip prostheses to determine the influence of patient-, implant- and surgery-related factors on the polyethylene wear rate and size of periprosthetic osteolysis (OL). This was calculated by logistic regression analysis. Factors associated with an increased/decreased wear rate included position of the cup relative to Kohler's line, increase in abduction angle of the cup, traumatic and inflammatory arthritis as a primary diagnosis, and patient height. Severe acetabular bone defects were predicted by an increased wear rate (odds ratio, OR = 5.782 for wear rate above 200 mm(3)/y), and increased height of the patient (OR = 0.905 per each centimetre). Predictors of severe bone defects in the femur were the increased wear rate (OR = 3.479 for wear rate above 200 mm(3)/y) and placement of the cup outside of the true acetabulum (OR = 3.292). Variables related to surgical technique were the most predictive of polyethylene wear rate.

PurposeThe combined use of reconstruction rings and modular trabecular metal (TM) augments can be a viable individual treatment in selected patients with large severe acetabular bone defects. However, clinical data on the outcome of this surgical technique is limited. This study aimed to evaluate mid‐term results of reconstruction rings used in combination with modular TM augments for severe acetabular defects in revision hip arthroplasty.MethodsWe retrospectively reviewed 23 patients with Paprosky type III A or B acetabular defects who underwent revision surgery using a reconstruction ring with a cemented cup in combination with a modular TM augment. 16 patients had type III A defects and 7 patients suffered from type III B defects. Clinical outcome was assessed using patient‐reported outcome scores (PROMs). CT scans were used to assess preoperative bone loss and plain radiographs were used to determine postoperative implant migration. Blood tantalum concentrations were measured at latest follow‐up and compared to a control group of patients without metal implants.Results18 patients could be contacted. 9 patients underwent a complete clinical and radiological follow‐up examination as well as a blood test. The cumulative survival rate at 7.4 years with the endpoint ‘acetabular component revision for any reason’ was 86.7% (95% confidence interval 56%–96%). At the most recent follow‐up two patients (9%) had undergone revision surgery due to aseptic loosening of the acetabular construct. Three patients showed radiological signs of loosening of the reconstruction ring without clinical symptoms. The PROMs improved significantly to the latest follow‐up. Blood tantalum concentrations were elevated in the study group (0.06 µg/L) compared to controls (0.002 µg/L) (p < 0.001).ConclusionsIn this study, favourable mid‐term (mean 7.4 years) clinical and radiological outcomes of modular TM augments in combination with a reinforcement ring and cemented revision cups for individual reconstructing major acetabular defects were observed. Aseptic loosening is the main reason for revision, whereby the TM augment was firmly osseointegrated in all cases.Level of EvidenceLevel IV, retrospective case series.