Acetabulum In Total Hip Arthroplasty Research Articles

Medium- to long-term clinical efficacy of total hip arthroplasty with structural bone grafting for dysplasia of the hip.

Patients with dysplasia of the hip (DDH) have different degrees of bone defects above and outside the acetabulum, and anatomically reconstructing the acetabular centre of rotation is difficult in primary total hip arthroplasty (THA). From April 2012 to December 2022, 64 patients (64 hips) with DDH treated with THA with structural bone graft in the superolateral acetabulum were selected. The Oxford hip score(OHS), Barthel index (BI), leg length discrepancy, Wibegr central edge-angle(CE), gluteus medius muscle strength, vertical and horizontal distance of the hip rotation center, coverage rate of the bone graft and complications were used to evaluate the clinical effectiveness of the patients. All patients were followed up for an average of 7.3±1.9 years. The OHS improved significantly after the operation (P<0.001). The postoperative BI was significantly greater than that before operation (P<0.001). The postoperative leg length discrepancy was significantly lower than that before the operation (P<0.001). Postoperative bedside photography revealed that the height and horizontal distance to the hip rotation center were significantly lower after surgery than before surgery (P<0.001). The postoperative CE was significantly greater than that before surgery (P<0.001). No acetabular component loosening or bone graft resorption was found during the postoperative imaging examination. The use of biological acetabular cup combined with structural bone graft in the superolateral acetabulum in THA for DDH can obtain satisfactory medium and long-term clinical and radiological results.

Use of dual mobility cup cemented into a tantalum acetabular shell for hip revision with large bone loss can decrease dislocation risk without increasing the risk of mechanical failure

BackgroundPorous tantalum components and augments have demonstrated short to midterm fixation stability in acetabular total hip arthroplasty (THA) revision but do not offer a novel option to decrease the postoperative dislocation rate. Recently, dual mobility (DM) cups have gained interest to decrease the prevalence of recurrent hip instability after revision hip arthroplasty, but this issue was not confirmed combined with use of tantalum reconstruction devices. Therefore, we did a retrospective study aiming to: (1) evaluate at a 5-year minimum follow-up period the dislocation rate (and other intra- and postoperative complications), (2) assess radiographic results specifically looking at osseointegration and restoration of the hip center, (3) and also clinical results in a cohort of patients who underwent complex acetabular reconstruction with trabecular metal revision components associated with a cemented DM socket. HypothesisUsing a DM socket cemented in porous tantalum components can reach the low risk of hip dislocation reported with DM components in revision setting without increasing the risk of a mechanical failure. MethodsA cross-sectional study identified 174 THA revision including an acetabular revision. Were excluded 118 revisions with acetabular defects Type 1, 2a or 2B according to Paprosky's classification, as well as 18 hips revised without a dual mobility and 3 patients (3 hips) lost to follow-up. Were thus included in this study 35 hips (35 patients) implanted with uncemented total hip arthroplasty revision using both trabecular metal acetabular cup-cage reconstruction and a cemented DM cup. Seven hips were classified Paprosky types 2C, 15 type 3A and 13 types 3B. Patients were followed with clinical and radiological evaluation regarding dislocation rate, infection, reoperation or re-revision, osseointegration and restoration of the hip center, and functional results according to the Harris hip score and psoas impingement presence. ResultsAt a mean follow-up of 8.1±1.8 years (5.1–12.6), one dislocation was recorded, and one acute deep infection. No patient required a cup re-revision for septic or aseptic loosening. The survivorship at 8years regarding revision for any cause as an endpoint was 96.5% (CI95%: 92–99). Osseointegration of TM implants was analyzed and found no acetabular migration at the last follow-up in the cohort. The mean hip center position was optimized from 48±7mm (37–58) to 34±5mm (29–39) vertically and from 26±5mm (–18–36) to 24±8mm (7–31) horizontally without reaching significance (p=0.1). On the last follow-up X-rays, the mean acetabular inclination was 47̊±9̊ (32̊–61̊). According to the criteria of Hirakawa, 97.1% (34/35) of the hip centers were restored. One cup (2.9%) was more than 5mm proximally from the hip center, and none more than 10mm. Clinical results assessed a Harris Hip Score improved from 36±17 (23–62) preoperatively to 82±15 (69–93) at last follow-up (p<0.0001). Two patients (2/35, 5.7%) complained of psoas impingement. ConclusionThis study suggests effectiveness of DM cups in association with a tantalum-made acetabular shell for reconstruction of large bone defect in THRs for both solving postoperative instability and aseptic loosening without increasing the re-revision rate for any reason in a midterm follow-up. Level of evidenceIV; observational study.

Evaluation results of using GAP II acetabular cage for acetabulum in revision total hip arthroplasty.

Acetabular revision arthroplasty with major bone loss is one of the most difficult operations in hip arthroplasty, The graft augmentation prosthesis (GAP) has been designed particularly as an implant for revision acetabular reconstruction. We evaluated the use of GAP II acetabular cage in revision of acetabulum in total hip arthroplasty. From 2009 to 2014, we performed revision total hip arthroplasty in patients with acetabular defects by cage (GAP II) in patients referred to Milad and Erfan Hospitals, Tehran, Iran. We included all patients in class 3a and 3b of Paprosky bone loss classification and type III bone loss according to the system of the American Academy of Orthopedic Surgeons. We used SPSS software Ver 19 and descriptive tests, Chi square and independent t-test were used for analysis. There were 221 men (71.99%) and 86 women (28.01%) with an average age of 51.3 ± 21.7 years (range, 35-86 years). The Modified Harris Hip Score (MHHS) improved significantly at the last follow-up compared with the preoperative MHHS (P < .001). The mean MHHS was 40 (range, 29-44) preoperatively and 92 (range, 86-95) at the last follow-up. There were no major intraoperative complications during acetabular reconstruction. Our findings showed that using GAP II acetabular cage in the restoration of acetabulum in hip revision surgery is significantly desirable.

A Reamer by Another Number: What Do They Actually Measure?

Acetabular reamers are a mainstay in the preparation of the acetabulum in total hip arthroplasty. Many surgeons, however, have noticed a discrepancy in the preparation of the socket and the reported size of reamers during this crucial phase of the procedure. A cross-sectional study performed by measuring a variety of sets of acetabular reamers was performed. The results showed that 17 of 21 sizes (81%) measured at least 2mm less than their reported size. Given that these differences beget unintended consequences, the industry may consider replacing or sharpening reamers already in use or even switching to a single-use reamer model.

Efficacy of structural bone graft for reconstruction of acetabulum in total hip arthroplasty in patients with developmental dysplasia of hips and severe acetabular defect

Efficacy of structural bone graft for reconstruction of acetabulum in total hip arthroplasty in patients with developmental dysplasia of hips and severe acetabular defect

Total hip arthroplasty with structural bone graft of superolateral acetabulum for developmental dysplasia of the hip

Objective To assess the mid- or long-term clinical outcomes of the structural bone graft of superolateral acetabulum in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). Methods Thirty-three patients with DDH (33 hips) were treated by THA with the structural bone graft of superolateral acetabulum technique between April 2002 and December 2011. There were 28 females and 5 males with the mean age at surgery 54.0±14.5 years (21-76 years). The degree of dislocation was graded preoperatively as Crowe II in 12 patients, Crowe III in 8 patients, and Crowe IV in 13 patients. The following outcomes were assessed, Harris hip score (HHS), the leg-length discrepancy, the height and horizontal distance of center of hip rotation, rate of cup coverage, the coverage ratio of bone graft, periprosthetic osteolysis, bone ingrowth, and cup loosening. Results The average follow-up was 9.3±3.3 years (5-15 years). The HHS improved from 40.9±13.7 preoperatively to 93.6±7.8 at the final follow-up (t=21.483, P=0.000). The leg-length discrepancy decreased from 24.2±17.1 mm pre-operatively to 3.7±3.5 mm at post-operative 3 months (t=6.747, P=0.000). The height and horizontal distance of center of hip rotation decreased from preoperative 45.9±16.0 mm and 42.9±8.7 mm to postoperative 23.8±5.8 mm and 23.6±2.9 mm (t=7.460, P=0.000; t=12.090, P=0.000) at post-operative 3 days, respectively. The cup coverage and coverage ratio of bone graft was 100% and 27.1%±6.9%, respectively. All grafts appeared to be incorporated without evidence of resorption and collapse. The mean time of incorporation was 7.6±2.8 months. The coverage ratio of bone graft >25% have a significantly long time of incorporation than that <25% (9.4±2.3 months versus 6.3±2.4 months, t=5.357, P=0.000). At the final follow-up, all hips showed bone ingrowth fixation of the acetabular cup and stem. Five hips showed osteolysis, two hips in acetabular zone II, three hips in femur zone I and five hips in femur zone VII. The main complications were intraoperative femoral fractures (61%) without neurological damage, nonunion and dislocation. Conclusion The structural bone graft of superolateral acetabulum in THA for DDH can achieve satisfactory mid- or long-term outcomes. The superolateral acetabular deficiency can be reconstructed by bone graft. The bone graft coverage less than 25% is conducive to fusion of bone graft and acetabular bone. However, intraoperative femoral fracture is common complication. Key words: Bone diseases, developmental; Bone transplantation; Arthroplasty, replacement, hip

Shortening subtrochanteric osteotomy and cup placement at true acetabulum in total hip arthroplasty of Crowe III\u2013IV developmental dysplasia: results of midterm follow-up

IntroductionThe anatomic abnormalities in developmental dysplasia of hip (DDH) often make total hip replacement (THR) inevitable at a younger age. However, there is no universal gold standard technique of THR for high dislocated dysplastic hips.Materials and methodsHere we present the outcomes of midterm follow-up after THR in patients diagnosed with DDH Crowe type III and IV hospitalized in a tertiary center in Iran for whom placement of a cup in true acetabulum and selective transverse subtrochanteric osteotomy was performed. Pre- and postoperative Harris Hip Score, leg length discrepancy and postoperative complications were evaluated.ResultsA total of 48 patients with DDH Crowe type III and IV (uni- or bilateral which made 52 hips) were studied. Mean age of patients was 41 years with minimum follow-up ranging from 12 months to 3 years. Mean Harris Hip Score significantly improved from 41.70 preoperatively to 88.1 at last follow-up postoperatively. Leg length discrepancy of less than 2 cm was observed which was well tolerated using shoe lifts. Regarding postoperative complications, two patients had transient peroneal nerve palsy in early postoperative period which recovered within 2 months. No other major complication was encountered.ConclusionTHR in patients with DDH (Crowe III and IV) with a cup positioned in true acetabulum and transverse subtrochanteric osteotomy is a safe successful procedure.

Reconstruction of the acetabulum in THA using femoral head autografts in developmental dysplasia of the hip

BackgroundSevere acetabular deficiencies in cases of developmental dysplasia of the hip (DDH) often require complex reconstructive procedures in total hip arthroplasty (THA). The use of autologous femoral head grafts for acetabular reconstruction has been described, but few data is available about clinical results, the rates of non-union or aseptic loosening of acetabular components.MethodsIn a retrospective approach, 101 patients with 118 THA requiring autologous femoral head grafts to the acetabulum because of DDH were included. Six patients had died, another 6 were lost to follow-up, and 104 hips were available for clinical and radiological evaluation at a mean of 68 ± 15 (13 to 159) months.ResultsThe average Merle d'Aubigné hip score improved from 9 to 16 points. Seven implants had to be revised due to aseptic loosening (6.7%). The revisions were performed 90 ± 34 (56 to 159) months after implantation. The other hips showed a stable position of the sockets without any signs of bony non-union, severe radiolucencies at the implant-graft interface or significant resorption of the graft.ConclusionThe use of autologous femoral head grafts with cementless cups in primary THA can achieve promising short- to midterm results in patients with dysplastic hips.

A semi-active milling procedure in view of preparing implantation beds in robot-assisted orthopaedic surgery

Bone cutting in total joint reconstructions requires a high accuracy to obtain a well-functioning and long-lasting prosthesis. Hence robot assistance can be useful to increase the precision of the surgical actions. A drawback of current robot systems is that they autonomously machine the bone, in that way ignoring the surgeon's experience and introducing a safety risk. This paper presents a semi-active milling procedure to overcome that drawback. In this procedure the surgeon controls robot motion by exerting forces on a force-controlled lever that is attached to the robot end effector. Meanwhile the robot constrains tool motion to the planned motion and generates a tool feed determined by the feed force that the surgeon executes. As a case study the presented milling procedure has been implemented on a laboratory set-up for robot-assisted preparation of the acetabulum in total hip arthroplasty. Two machining methods have been considered. In the first method the surgeon determines both milling trajectory and feed by the forces that he/she executes on the force-controlled lever. In the second method the cavity is machined contour by contour, and the surgeon only provides the feed. Machining experiments have shown that the first method results in large surface irregularities and is not useful. The second method, however, results in accurate cavity preparation and has therefore potential to be implemented in future robot systems.

Assessment of bone graft substitutes in autopsy implant retrievals of the acetabulum in total hip arthroplasty

Two autopsy retrievals of acetabular reconstruction with different bone graft substitutes were analyzed. One patient underwent surgery with hydroxyapatite (HA) granules, and the other with demineralized bone chips. Incorporation occurred with the biomaterial bone-graft substitute HA primarily in the superior part of the acetabulum, where the HA was in contact with host cortical bone. No bony union occurred with the demineralized bone chips because of motion and migration of the acetabular cup. No bone incorporation of either bone-graft substitute was observed in the medial wall defects in both patients. There were two important findings: (1) the 3- to 8-mm depth and 70% to 75% surface of union of the HA bone graft substitute to host cortical bone was the same as seen with morselized, fresh-frozen bone graft; and (2) union of graft material to host bone was dependent on secure fixation of the acetabular construct.

The incidence of cement extrusion from the acetabulum in total hip arthroplasty

Acetabular cement extrusion (CE) is a common finding after total hip arthroplasty, but the incidence is unclear from the literature, and there is no accepted way of measuring it. We report a retrospective observational study of 100 patients (25 consecutive patients from each of 4 consultants, 112 hips) to determine the site and incidence of CE on postoperative radiographs, and to measure its area and the maximum distance of the extruded cement from the edge of the cement mantle. We found that 50 of 112 (44.6%) hips showed evidence of CE, with a 15.2% incidence of CE > 200 mm2. © 2003 Elsevier Inc. All rights reserved.

Acetabular Revision Total Hip Arthroplasty Using Uncemented Cup and Morselized Impacted Allograft

Purpose : This study was undertaken to evaluate the clinical and radiographic results of acetabular revision arthroplasty using an uncemented big cup & a morselized impacted allograft. Materials and Methods : This study involved 81 hips of 77 patients experienced over a 2 year period (2-8 years 10 months). The bone defects of the acetabulum were classified by AAOS classification and by the Paprosky classification. We inserted an unce-mented hemispherical cup by press-fitting technique as large size as possible. Only morselized impacted allograft was used for the bone defect. Results : The average Harris hip score was 95.9. One case (Paprosky type IIIB) received revision with only morselized allograft and failed to achieve initial stability. Therefore re-revision was performed with tricortical autograft and morselized allograft which has been well maintained until now for 3.5 years. Vertical migration and horizontal migration of more than 3 mm were noted in five cases and two cases, respectively. Rotational migration of more than 8 degree was not noted. A radiolucent line between bone & cup was seen in 9 cases, and a radiolucent line between host bone & grafted bone in 2 cases, this line was less than 2 mm large. Conclusion : We believe this method is a good option in revision acetabular total hip arthroplasty.

Cemented total hip arthroplasty with acetabular bone graft for developmental dysplasia

Although the technique of autogenous acetabular bone grafting has been widely used to augment containment of the acetabulum in total hip arthroplasty (THA) for developmental dysplasia, the role of this technique in improving long-term results remains controversial. We present the long-term results of cemented THA with acetabular bone grafting in 112 patients (133 hips) in order to clarify the factors which affect the outcome. The mean follow-up was for 12.3 years (8 to 24). Kaplan-Meier survivorship analysis predicted a rate of survival of the acetabular component at 15 years of 96% (95% confidence interval (CI) 92 to 99) with revision for aseptic loosening as the endpoint, and of 75% (95% CI 65 to 85) when radiological loosening was used. Parametric survivorship analysis using the Cox proportional-hazards model indicated that trochanteric nonunion, lateral placement of the socket, and delayed trabecular reorientation of the bone graft were risk factors for loosening of the acetabular component. Our findings have shown that autologous acetabular bone grafting is of value for long-term success provided that the risk factors are reduced.

Bulk structural autogenous grafts and allografts for reconstruction of the acetabulum in total hip arthroplasty. Sixteen-year-average follow-up.

Acetabular reconstruction with bulk structural autogenous grafts and allografts from the femoral head in complex total hip arthroplasty was highly successful at an average of five years postoperatively but was much less so by 11.8 years. To assess the longer-term fate of such grafts, we reviewed the results of eighty-one consecutive total hip arthroplasties performed by the senior one of us with use of these grafts. Nine hips in nine patients who had died and two hips that were infected in two patients were excluded. Therefore seventy hips (sixty-two patients) were included in this study. The average duration of follow-up was 16.5 years (range, 14.1 to 21.4 years). Sixty-one arthroplasties were performed to treat various forms of congenital dysplasia. Fifteen arthroplasties, ten of which were revision operations, were performed with allograft, and fifty-five were performed with autogenous graft. The average age of the patients at the time of the index operation was 45.2 years (range, sixteen to sixty-nine years). All of the sockets, which had an average outer diameter of forty millimeters (range, thirty-four to fifty millimeters), were inserted with cement. The average coverage of the acetabular component by the bulk graft was 49 per cent (range, 15 to 100 per cent). All of the grafts united. At the latest follow-up examination, twenty-five acetabular components (36 per cent) had been revised for aseptic loosening, eighteen (26 per cent) had radiographic evidence of loosening, and twenty-seven (39 per cent) were rigidly fixed and in place. The average Harris hip score for the hips in which the implant remained rigidly fixed was 74 points, while that for the hips in which the implant was loose but had not been revised was 69 points. Nine of the fifteen acetabular components supported by allograft and sixteen (29 per cent) of the fifty-five supported by autogenous graft were revised (p = 0.03). However, the total rate of acetabular components that were either loose or revised was ten of fifteen and thirty-three (60 per cent) of fifty-five, respectively. This difference was not significant (p = 0.4), with the numbers available. Regression analysis revealed that a younger age at the time of the operation and the extent of coverage of the acetabular component by the graft were associated with the need for revision. Twenty-one (78 per cent) of the twenty-seven acetabular components that remained rigidly fixed were supported by graft over less than 50 per cent of the contact area, while only nine (36 per cent) of the twenty-five that were revised were so supported (p < 0.05). None of the nine acetabular components with 30 per cent of the contact area or less covered by graft were revised. In nineteen of the twenty-two revisions of the acetabular component performed after the index operation, the socket was inserted without cement; the average outer diameter of the socket was fifty-three millimeters (range, forty to fifty-eight millimeters). Both the structural autogenous grafts and the structural allografts used in acetabular reconstruction in total hip replacement functioned well for the initial five to ten years. By an average of 16.5 years, nine of the fifteen hips treated with allograft and sixteen (29 per cent) of the fifty-five treated with autogenous graft had been revised. The greater the extent of the coverage of the acetabular component by the graft, the greater the rate of late failure.