Assessment Accuracy of 2D vs. 3D Imaging for Custom-Made Acetabular Implants in Revision Hip Arthroplasty.

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.

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.

Introduction:Total hip arthroplasty (THA) in patients with severe acetabular bone defects remains technically demanding. Although favorable outcomes have been reported with Kerboull-type acetabular plates, the clinical results of the Restoration GAP II reinforcement ring (GAP II ring) have been inconsistent. We report a case of hip osteoarthritis with severe acetabular bone defects following rotational acetabular osteotomy, successfully treated with THA using the GAP II ring.Case Report:We report a case of an 80-year-old woman who underwent rotational acetabular osteotomy 20 years ago and subsequently developed hip osteoarthritis with severe acetabular bone defects that required acetabular reconstruction. Anatomical placement of the acetabular component and fixation with a cementless cup were deemed inapplicable due to the extent of the bone defects.Conclusion:Therefore, the Restoration GAP II reinforcement ring, which has multiple screw insertion points and customizable hook bending, was selected for reinforcement. Given the poor bone quality, autologous bone grafting was considered unsuitable, and bone cement was used to fill the defects. Total hip arthroplasty was successfully performed using the reinforcement ring, and the patient was allowed full weight-bearing ambulation from post-operative day 1.At 18 months after surgery, she reported no recurrence of pain or difficulties in walking. This case suggests that satisfactory outcomes can be achieved in cases with severe acetabular bone defects through the appropriate application of a reinforcement ring.

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

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.

Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor. Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason. Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance. We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still furtherresearch using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

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.

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.

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.

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.

Mid-Term Results of Graft Augmentation Prosthesis II Cage and Impacted Allograft Bone in Revision Hip Arthroplasty

Few studies have investigated the relationships between preoperative or intraoperative patient factors and postoperative quality of life (QOL) after revision total hip arthroplasty (THA). The aim of our study was to identify the predictors of QOL after revision THA for aseptic loosening. Fifty-one patients who underwent revision THA for aseptic loosening were included in the present study. Preoperative hip function was evaluated using the Japanese Orthopaedic Association (JOA) score. The patients' QOL after surgery was evaluated with EuroQol 5D (EQ-5D) assessment at the end of the 2-year follow-up. The patients were then divided into two groups: good QOL (score ≥ 0.6) and poor QOL (score < 0.6). Predictive factors (i.e., age, BMI, preoperative JOA score, and the degree of acetabular bone defect according to the Paprosky classification) were compared between both QOL groups. Furthermore, multiple linear regression was performed to assess independent factors affecting the QOL. Significant differences between the good and poor QOL groups were identified for BMI, walking ability, and severity of acetabular bone defect (BMI: 21.5 ± 2.9 vs. 24.1 ± 4.3, P = 0.0331; walking ability: 11.5 ± 5.0 vs. 5.5 ± 4.9, P = 0.0058; acetabular bone defect: 44.4% vs. 81.0%, P = 0.0103). The walking ability independently affected the EQ-5D utility score. The present study indicates that a higher BMI, lower walking ability, and more severe acetabular bone defect are predictors of lower QOL after revision THA for aseptic loosening. In particular, the walking ability was the only independent factor. Thus, surgeons should pay attention to the postoperative management of patients with these risk factors.

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.

Restoring normal anatomy and achieving stable fixation of the acetabular component can be especially challenging when the surgeon must deal with severe acetabular defects and/or pelvic discontinuity. The cup-cage (CC) construct, where an ilioischial cage is cemented within a biologically fixed porous metal cup, has emerged as an excellent option to treat such challenges. We sought to determine (1) mid-term Kaplan-Meier survival; (2) clinical outcomes based on Merle d'Aubigné-Postel scores; (3) radiological outcomes based primarily on construct migration; and (4) the complication rate for a series of 67 CC procedures performed at our institution. All hip revision procedures between January 2003 and March 2012 where a CC was used (with the exception of tumor cases or acute fracture; four total cases) that had a minimum 2-year followup and that had been seen within the last 2 years were included in this retrospective review. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven CC procedures with an average followup of 74 months (range, 24-135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Postoperative clinical and radiological evaluation was done annually. Merle d'Aubigné-Postel scores were recorded and all radiographs were compared with the 6-week postoperative radiographs to evaluate for radiographic loosening or migration. Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval [CI], 83.1-97.4), and the 10-year survival rate was 85% (95% CI, 67.2-93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 preoperatively to 13 postoperatively (p < 0.001). Four CC had nonprogressive radiological migration of the ischial flange and they remain stable. We believe that the CC construct is a suitable choice to treat chronic pelvic discontinuity; it also remains a reliable option for the treatment of severe acetabular bone defects if stable fixation cannot be obtained through the use of a trabecular metal cup with or without augments. Level IV, therapeutic study.