Cementless distally locked stems were introduced in revision hip arthroplasty (RTHA) in the late 1980s to deal with severe femoral bone loss. These implants have not been assessed over the long-term, particularly the influence of the design and porous coating. Therefore we performed a retrospective case-control study at a minimum 10-years' follow-up comparing the straight Ultime™ stem with 1/3 porous coating versus the anatomical Linea™ stem with 2/3 proximal coating with hydroxyapatite.

We performed a single-center case-control study measuring survival, function based the Harris and Oxford-12 scores, and rate of thigh pain. X-rays were done at regular intervals and at follow-up. No femoral bone graft was used at insertion.

The two groups were comparable in terms of age, sex and follow-up (mean 12.2 years in Ultime and 10.8 years in Linea cohorts); however they differed in the severity of bone loss therefore the results were adjusted according to this variable. Ten-year survival considering revision for any reason was 63.5% ± 5.4 for Ultime and 91.6% ± 2.7 for Linea (p < 0.001). Merle d'Aubigné scores and Oxford-12 were higher in the Linea group 82.9 ± 12.4 and 26.3/48, respectively, versus 69.5 ± 16 and 21/48 in the Ultime group (p < 0.001). Thigh pain was observed in 30% of Ultime cases versus 3% of Linea cases. Bone reconstruction measured via cortical thickness was better in the Linea group and correlated to metaphyseal filling at insertion.

This study confirms the benefits of using of locked stems in RTHA with severe bone loss. Better metaphyseal filling and optimized porous coating help to minimize thigh pain and the revision rate.

Purpose of the study: Locked implants have yielded favourable results for femoral bone reconstruction for revision total hip arthroplasty, but defective integration has also been reported due to insufficient bioactive coating. The purpose of this work was to evaluate a locked pivot with a two-third proximal hydroxyapatite coating.

Material and methods: From 1996 to 2007, 158 femoral implants (Linea™) were implanted for hip arthroplasty revision. The 143 cases with more than one year follow-up were reviewed (14 deaths, 1 lost to follow-up); 83 revisions for aseptic loosening, 41 periprosthetic fractures, 19 revisions in an infected context. Patients were reviewed retrospectively by a non-operator observer. These were older patients (mean age 68 years, range 31–93) and 36 patients had complex situations requiring at least two prior prostheses; 25% had severe grade 3 or 4 (SOFCOT) bone lesions and 59% diaphyseal damage.

Results: Clinical improvement was significant, the Postel Merle d’Aubigné score improved from 7.7 + 4.3 (0–17) to 15.6 + 2.2 (8–18) at mean 50 months (14–131) (p< 0.001). At last follow-up, 14 patients (10%) reported thigh pain and only seven pivots (5%) had not achieved Engh osteointegration (five with thigh pain two without). There were no fractures. There was on non-union of the femorotomy. According to the Hoffman index, femoral bone regeneration was significant at the metaphyseal and diaphyseal levels. Eighteen of the 19 infections cured, all periprosthetic fractures healed. The implant survival was 88.9% at 91 months (65–96.7%). There were five pivot replacements for non integration and/or thigh pain which resolved in all cases; there were no other pivot replacements. The quality of the metaphyseal and diaphyseal filling was predictive of the quality of the bone fixation of the pivot (p< 0.01).

Discussion: Compared with older models of locked pivots, this implant reduced the rate of thigh pain while allowing constantly satisfactory bone reconstruction. The metaphyseal and diaphyseal filling index is the main factor predictive of clinical and radiological success by favouring osteointegration. Maximal filling, obtained with a full range of implant diameters and lengths, contributes to this good result.

Purpose of the study: Drilling along yields disappointing results for osteonecrosis of the femoral head due to the high failure rate despite prolonged rest and also because of the risk of fracture. To prevent these problems, we have developed a new drilling technique which was evaluated prospectively.

Material and methods: The procedure performed percutaneously uses a lateral cortical orifice measuring 5mm, non-concentrated autologous bone marrow was injected after drilling. Osteoinductive protein (BMP7) was associated in random fashion (groups BMP+ and BMP−). Ficat stage 1 and 2 necrosis was included. Outcome was the rate or revision for prosthesis.

Results: Forty hips (36 patients) were included and assessed at mean four years (range 2–6). The necrosis was related to: alcoholism (n=5), cortisone (n=25), barotraumas (n=2), metabolic disease (n=4), idiopathic condition (n=4). Group BMP- (drilling+bone marrow) included 24 hips and group BMP+ (drilling+bone marrow+BMP7) 16 hips. The groups were comparable regarding necrosis stage (15% stage 3, 65% stage 2, 20% stage 1) and mean Koo index (27 BMP+ vs 34 BMP-; NS). There were no infections and no fractures despite immediate and complete weight-bearing. The revision rate for prosthesis was higher in the BMP- group (67%) than in the BMP+ group (43%) but the difference did not reach significance (p=0.10). The failure rate was not affected by the severity of the necrosis in the BMP+ group: all stage 3 hips were revised in the BMP- group versus none in the BMP+ group. The only variable predictive of revision for prosthesis was the Koo index (p=0.02).

Discussion: Adjunction of BMP did not improve significantly the success rate of drilling with bone marrow adjunction but adding BMP appeared to limit the unfavourable impact of server necrosis observed in the BMP- group. To reach a statistical power of 80%, 40 cases would be needed in each arm. This threshold has not yet been reached. It can be noted however that the proposed method does ensures early weight bearing without the risk of complications. Similarly, since it is a percutaneous procedure, later arthroplasty is not compromised. The principle confounding factor, the richness of the bone marrow, was not assessed, motivating a new randomized trial with measurement of CFU-F.

Introduction: The prosthetic impingement occurs if the range of motion of the hip exceeds implant mobility or in case of component malorientation. This phenomenon is rarely studied in the literature and most data have come from sporadic cases. This study was designed to assess the frequency and the risk factors of this phenomenon.

Material: The frequency and the severity of the impingement were calculated from a continuous series of 413 cups retrievals. These cups were examined macroscopically twice by two independent observers. The cam effect was noted as: absent, grade 1 (visible at gross inspection but measuring < 1 mm), grade 2 (notch measuring 1–3 mm), grade 3 (notch measuring > 3 mm). The risk factors were analyzed for 298 retrievals that had complete clinical charts.

Results: Among the 413 cups explants, the frequency of impingement was 51.3 percent (grade 3 in 12% and grade 2 in 24%). The impingement was the reason for removal in only 1.7 percent (only for hard bearings), meaning that impingement was mainly an unexpected event (98.3 percent). The impingement was more frequent when revisions were performed because of instability (80 percent; odd-ratio 4.2 (1.1–16.2)) than for loosening (52%) osteolysis (59%) or infection (38%) (p =.002). Likewise, impingement was more frequent when the sum of hip motion exceeded 200 degrees (sum of motion in the 6 degrees of freedom of the hip) (66% versus 45% if the sum was below 200°). The other risk factors were: use of heads with skirts (78% versus 55%), liner with an elevated rim (73% versus 55%), and head-neck ratio below 2.

Discusssion and conclusion: This study underlines the impingement is common when assessing cup retrievals (over 50 percent). One should be aware of impingement when performing hip replacement in patients having a high range of motion. This situation may require prostheses with a high head-neck ratio, as well as use of computer-assisted surgery. One should avoid liners with elevated rim as well as heads with skirts to prevent dislocation, particularly when other risk factors are detected.

Introduction: Cementless revision hip arthroplasties require a stable initial fixation that does not compromise a subsequent bone reconstruction. In case of severe femoral bone loss, stems usually requires distal fixation that may induce stress shielding and finally reduce the spontaneous bone reconstruction. We introduced the use of distally locked revision stems in 1993 hoping strong fixation and bone reconstruction. The goal of the current study was to assess if these components fulfill these two objectives.

Materials and Methods: 101 cementless femoral revision stems with distal locking by screws (Ultime™ Wright-Cremascoli) were inserted from 1993 to 2001. These stems were smooth distally and porous coated with or without HA 1/3 proximally. The indication to use these components was severe bone loss (Paprosky grade IIC and III in 51%) when press fit distal fixation could not be obtained. The use of bone graft was limited to segmental defects or to treat trochanteric non-union. An extended trochanteric osteotomy was performed in 89%. The revision was performed because of aseptic loosening in 43,4%, periprosthetic fracture in 24,2% and infected loosening in 25,2%. The results were assessed after a mean follow-up of 6 years (5–12).

Results: 13 patients deceased and 2 were lost for follow-up. All the extended trochanteric osteotomies healed. Merle d’Aubigné hip score increased from 8.3 to 13.4, but thigh pain was observed in 44%. Bone reconstruction was significant according to Hoffman index at 3 levels of assessment. The 5-year survivorship was 87% considering aseptic revision for any reason. Seventeen repeated femoral procedures were performed: 9 related to thigh pain (because there was no proximal osteointegration) that were revised for short primary stems, 8 because of stem fractures (all occurred at the level of the proximal hole with the same stem size because there was no proximal fixation as long as the stems were smooth or without HA-coating.

Discussion: This serie has the longest follow-up using locked revision stems. Despite severe pre-operative bone loss, primary fixation and significant bone reconstruction were obtained for all the cases without extensive bone grafting. The major weakness, thigh pain and stem break, were related to unadequate femoral coating for these cementless stems that did not achieved osteointegration. Conversly, the reoperations were simple, allowing the use of short primary designs as bone reconstruction was achieved in all cases without extensive bone grafting. These locked stems allow a strong primary distal fixation that does not compromise bone regeneration. An improvement of femoral coating (extension to 2/3 and use of hydroxyapatite) may reduce the rate of thigh pain and reoperation.

Purpose of the study: The incidence of revision hip arthroplasty is increasing. In order to overcome certain problems related to loss of femoral bone stock, an original technique was developed combining fragmented allograft material and a metallic mesh with a non filling stem cemented distally in a healthy zone to ensure stability.

Materials and Methods: The clinical data (Postel-Merle-d’Aubigné, PMA score) and radiographic findings (implant migration, loss of bone stock using the SOFCOT and PAPROSKY classification, quality of cementing, filling, and graft aspect, graft lysis, periprosthetic lucency, final aspect of the graft) were collected retrospectively. The operation and the technical difficulties and intraoperative complications were noted.

Results: We report a series of 32 hips treated with this technique and having a mean follow-up of 12.5 years (range 8–20 years). The population studied had particularly significant bone loss (78.2% SOFCOT stage 3 and4). These hips underwent revision for aseptic loosening. The implantation technique required a femoral window in 39.1%. Preventive cerclage was often used (39.1%) but did not prevent fracture or missinsertion in 30.4%. The PMA score improved significantly from 10.6 (7–18) preoperatively to 17 (12–18) at last follow-up. Radiologically, femoral bone regeneration at last follow-up had an aspect of corticalisation in 63.6% of hips, and of cancellous trabeculation in 36.4%. Femoral implant survival was 100% at eight years, and 92.8±6.88% at mean follow-up of 12.5 years. There was only one revision at eleven years for secondary osteolysis related to polyethylene wear in a very active subject implanted before the age of 50 years.

Discussion: The clinical and radiographic results are very satisfactory for this series of femoral revisions using an impacted fragmented graft material and with the longest follow-up reported in the literature. Distal fixation limited migration observed when the stem is entirely cemented in the graft, but did not affect reconstruction which demonstrated long-term stability. This technique, initiated in 1986 without a specific instrument set, had now demonstrated its long-term reliability. The only problem is the length of the operation and the complications related to femoral preparation.

Introduction: The anterior pelvic plane (APP), described by Lewinnek, is defined by the following points : anterior iliac spines, pubic symphysis. This plan is mostly considered as vertical in weight bearing and is currently used as the reference to guide cup insertion by means of imageless computer assistance (CAS). However, to our knowledge, there is no data that strongly confirm APP is vertical in weight bearing and how much his orientation is modified with regards operative position, or THA insertion. This study assessed these data by means of a radiological analysis.

Material and Methods: The orientation of the APP was measured with regards to the vertical plane on weight-bearing profile X-rays of the pelvis in 106 subjects including:

1) 82 patients with THA (40 who had at least one dislocation, and 42 matched patients without instability randomly selected, 19 of these 42 underwent a profile X-ray of the pelvis before and after THA insertion)

Results: Thirty-eight percent of the subjects in weight-bearing had an orientation of the APP different of more than ± 5° from vertical plane and 13% were out of the interval ±10°. The orientation of the APP was not significantly different between the groups (standard and THA) nor between the groups who had stable or unstable THA. The orientation of the APP was significantly modified between lying and weight-bearing posture, from a mean of 1,2° lying to −2,25° upright. Under these conditions, 12 subjects presented a variation of more than 7°. Insertion of a THA did not significantly modify the orientation of the APP in weight-bearing among the 19 subjects (variations were small (−1° ± 7° [from – 21° to 8°]), but were more than 5° for 7 of the 19 subjects).

Discussion and Conclusion: Most of the surgeons use the APP as a reference to guide navigation for cup insertion, considering it is vertical in weight-bearing. However, it is not true for 38% with a margin of 10°, which is equivalent to approximately half of the anatomical anteversion of the acetabulum. Standing up produced a significant variation of the orientation of the APP with regards to lying position. These errors that are not integrated by most of the CAS without preoperative CT scans, may produce cam effect or dislocation when the patient is moving to sited position. The variations of APP orientation with regards to vertical plane suggest it is not adequate to guide the CAS insertion of the cup. There is no reliable reference, easily identifiable during surgery that integrates the variations of position of the pelvis. This leads us to promote a new CAS for THA insertion free of reference plane, based on kinematics.

Purpose of the study: In order to evaluate the influence of prosthesis design and resurfacing on the outcome of total hip arthroplasty (THA) implanted without cement, we reviewed the orthopedic literature from 1980 to 2004.

Material and methods: The PubMed database was screened from 1980 to 2004 for publications reporting cementless THA with a follow-up analysis. The same criteria were used to screen three registries. In all, the publications retained had studied 50,162 cementless THA (mean patient age 48.9 years, mean follow-up 6.5 years) where were studied according to rate of revision, presence of osteolysis, and presence of operative fractures. Eleven families of components grouped together the majority of prostheses: five acetabular families [screw fixation without resurfacing (n=2997), screw fixation with hydroxyapatite (HA) resurfacing (n=3618), screw fixation with corindon resurfacing (2360), press-fit mac-roporous (15691), press-fit HA (6094)]; and six families of femoral pivots [straight macroprous (n=7502), straight HA (n=3255), straight corindon (n=6136), anatomic HA (n=3468), anatomic macroporous (n=1215), anatomic corindon (n=1041)].

Results: The rates of revision and of osteolysis were higher for screw fixed cups without resurfacing. For screw fixed or press-fit cups, HA resurfacing did not reduce the rate of revision compared with corindon coated or macroporous implants. For anatomic pivots, adjunction of HA resurfacing reduced the rate of revision but at the shortest follow-up and without reducing the rate of osteolysis. Corindon-coated pivots gave comparable results for straight or anatomic implants. Conversely, HA-coated pivots gave better results with an anatomic design. The shape of the pivot had les effect than resurfacing on osteolysis and revision, but had a greater influence on operative fractures (2.9% for straight implants versus 4.6% for anatomic versions).

Conclusion: In all:

uncoated implants should be abandoned;