Treatment of Paprosky type Ⅲ severe acetabular bone defects with two revision methods

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.

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

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.

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.

Objective To evaluate the mid-term clinical and radiographic outcomes of acetabular revision for Paprosky IIIA or IIIB acetabular bone defects. Methods Thirty consecutive acetabular revisions were conducted with allograft bone transplant, metal augment or reinforcement combined with cement or cementless cup in 29 patients with a severe Paprosky III acetabular bone defects from January 2002 to June 2012. There were 17 males and 12 females with average age 64.7±2.9 years. Eleven hips had acetabular reconstruction using cementless cup and augment, nineteen hips were revised using allograft bone transplant, acetabular reinforcement ring and cement cup. Hip function of patient was evaluated by Harris score at pre- and post operation. The outcomes of acetabular prostheses and bone grafts were assessed by radiographic analysis. The 10-years components survival rate was assessed by Kaplan-Meier survivorship analysis. Results Twenty-seven patients (28 hips) had a minimum 4-year follow-up, ranged from 4.4 to 11.8 years (6.8 years on the average). The average Harris score improved from pre-operative 31.4±5.7 to 88.3±3.9 at the final follow-up (t=6.392, P <0.001). The leg discrepancy was improved from preoperative 28.4±10.2 mm to postoperative 1.4±2.8 mm (t=7.391, P <0.001). The hip rotation center was reconstructed from preoperative 35.3±6.4 mm to postoperative 3.2±5.8 mm (t=9.427, P <0.001) lateral-toward dislocation to inside Ranawat triangle. The allograft bone was incorporated with the host bone during 6 months to 2 years postoperatively. Radiographic analysis of all 28 hips showed that there was no component loosening, and among of them, 5 hips had a non-progressive radiolucent line. No screw or cement fracture and no cage displacement occurred. There was no moderate or severe bone absorption at the final follow-up. Kaplan-Meier analysis demonstrated that a ten-year component survival rate was 100% (95%CI: 0.95, 1.00). Conclusion In hip revision surgery, most of Paprosky IIIA acetabular bone defects are characterized by continuous acetabulum and relative intact of anterior and posterior column, which is suitable to take metal augment and cement cup to reconstruct. Most of Paprosky IIIB acetabular bone defects have discontinuous acetabulum and severe destruction of anterior/posterior column. Restoration hip rotating center and satisfied midterm outcomes benefit from allograft bone transplant combined with acetabular reinforcement ring and cement cup. Key words: Arthroplasty, replacement, hip; Reoperation; Acetabulum; Osteolysis; Bone transplantation; Tantalum

To investigate the short- and mid-term effectiveness of revision hip arthroplasty by using impaction bone allograft and acetabular components in treatment of severe acetabular defects. A clinical data of 42 patients (44 hips) with severe acetabular defects between February 2011 and May 2018 were retrospectively analyzed. All patients underwent revision hip arthroplasty by using impaction bone allograft and acetabular components. Cemented cup (24 cases, 24 hips) and non-cemented cup (18 cases, 20 hips) were used in the revision surgery. There were 17 males and 25 females with an average age of 62.8 years (range, 22-84 years). The interval between the first total hip arthroplasty and revision was 2.5-12.0 years (mean, 8.3 years). The patients were accepted revision surgery for prosthesis aseptic loosening in 32 hips (31 cases) and the periprosthetic infection in 12 hips (11 cases). Twenty-nine hips (28 cases) were Paprosky type ⅢA and 15 hips (14 cases) were type ⅢB. The preoperative Harris score was 22.25±10.31 and the height of hip rotation center was (3.67±0.63) cm and the length difference of lower limbs was (3.41±0.64) cm. The operation time was 130-245 minutes (mean, 186 minutes) and the intraoperative blood loss was 600-2 400 mL (mean, 840 mL). The postoperative drainage volume was 250-1 450 mL (mean, 556 mL). Superficial infection of the incision occurred in 1 case, and the incisions healed by first intention in the other patients. All patients were followed up 6-87 months, with an average of 48.6 months. At last follow-up, the Harris score was 85.85±9.31, which was significantly different from the preoperative score ( t=18.563, P=0.000). Imaging examination revealed that the allogeneic bone gradually fused with the host bone, and no obvious bone resorption was observed. At last follow-up, the height of the hip rotation center was (1.01±0.21) cm, which was significantly different from the preoperative level ( t=17.549, P=0.000); the length difference of lower limbs was (0.62±0.51) cm, which was significantly different from the preoperative level ( t=14.211, P=0.000). The Harris score in the cemented group and non-cemented group increased significantly at last follow-up. The height of the hip rotation center decreased, and the hip rotation centers of both groups were within the Ranawat triangle zone. The length difference of the lower limbs also decreased, and the differences in all indexes were significant between pre- and post-operation ( P<0.05). There was significant difference in the height of the hip rotation center between groups ( t=2.095, P=0.042), but there was no significant difference in the Harris score and the length difference of lower limbs between groups ( P>0.05). For severe acetabular defect (Paprosky type Ⅲ), the hip can be reconstructed with the impaction bone allograft and cemented or non-cemented components in revision hip arthroplsty. The short- and mid-term effectiveness are satisfactory.

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.

PurposeRestoration cages and bone allografts have been proposed to manage severe acetabular bone defects. We aimed to investigate the migration behaviour of a restoration cup and impacted allograft bone in severe acetabular defects with Einzel-Bild-Röntgen-Analyse (EBRA).MethodsApplying a retrospective study design, 64 cases treated between 2009 and 2016 were reviewed. We determined the preoperative Charlson Comorbidity Index (CCI), pre- to postoperative WOMAC score, blood loss and functional outcome. From preoperative x rays, the acetabular deficiencies were classified according to Paprosky. Cup migration analyses were performed with EBRA.ResultsMean age at surgery was 73 (range: 38–93) years. According to the classification by Paprosky et al., 50% (n = 32) of our patients showed a type III B and 28.1% (n = 18) a type III A defect. Radiological follow-up for migration analysis was 35 (range: 4–95) months. Migration analysis showed a mean cup migration of 0.7 mm (range: 5.7–9.6) medial and 1.8 mm (range: 1.7–12.6) cranial.ConclusionIn conclusion, acetabular restoration cages in combination with bone impaction grafting showed a low revision rate at a mean follow-up of 35 months. Mean cup migration revealed low rates after 2 years and suggested a stable postoperative implant position.

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.

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.

PurposeThe purpose of this study is to report the short-term outcomes of revision total hip arthroplasty (THA) using tantalum augments in patients with severe acetabular bone defects.Materials and MethodsWe retrospectively analyzed 15 revision THAs performed in 15 patients using tantalum augments between June 2010 and December 2013. Acetabular bone defects were Paprosky type IIIA in 7 hips, type IIIB in 7, and type IV in 1. The causes of revision surgery were aseptic loosening in 12 hips and deep infection in 3. Revisions were first in 1 hip, second in 3, and third in 11. Six patients were male and 9 female with a mean age of 59 years (range, 48-75 years). Mean follow-up was 29 months (range, 24-48 months).ResultsMean Harris hip score was improved from 34 points (range, 12-54 points) preoperatively to 84 points (range, 38-90 points) at final follow-up. On the final follow-up radiographs, there were 12 hips (80.0%) with stable fixation of the acetabular cup, 2 (13.3%) with secondary stability after mild acetabular protrusion, and 1 (6.7%) with radiolucency around the acetabular cup without mechanical symptoms. Complications included one patient with acute hematogenous infection managed by surgical debridement and long-term antibiotic therapy. There were no cases with nerve palsy or dislocation during the follow-up period.ConclusionThe present study showed satisfactory clinical and radiographic outcomes of revision THA using tantalum augments due to severe acetabular bone defects of Paprosky type III or IV at a minimum follow-up of 2 years.

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.

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.