Purpose: Radiographic signs of osseointegration have been well established for cementless femoral components, but not for cementless acetabular components. At our institution using principles similar to those applied to cementless femoral components, we have observed apparent radiographic signs of osseointegration of porous-coated cups. We then hypothesized that these signs could be used to predict bone ingrowth of porous-coated acetabular components. Methods: In a series of 119 total hip arthroplasties with porous-coated cementless cups, we reviewed post-primary and prerevision serial radiographs and proposed five radiographic signs for detecting osseointegration of a porous-coated acetabular component: absence of radiolucent lines, presence of a superolateral buttress, medial stress shielding, radial trabeculae, and an infero-medial buttress. We compared the predictability of each sign to intraoperative findings of cup stability and measured the sensitivity, specificity, and intra-observer agreement of each sign. Results: . In our population, ninety-eight cups had three to five radiographic signs of osseointegration; of these, ninety-five cups (97%) were found to be bone-ingrown at the revision operation. Conversely, twelve cups had only one or no sign; of these, ten (83%) were clinically unstable at the revision operation. Conclusions: We concluded these five, readily detectable signs of acetabular osseointegration are very useful in predicting acetabular component stability found at surgery

Introduction. Durable bone fixation of uncemented porous-coated acetabular cups can be observed at a long-term, however, polyethylene (PE) wear and osteolysis may affect survivorship. Accurate wear measurements correlated with clinical data may offer unique research information of clinical interest about this highly debated issue. Objetive. We assessed the clinical and radiological outcome of a single uncemented total hip replacement (THR) after twenty years analysing polyethylene wear and the appearance of osteolysis. Materials and Methods. 82 hips implanted between 1992 and 1995 were prospectively evaluated with a mean follow-up of 20.6 years (range, 18 to 23). A hemispherical porous-coated acetabular cup matched to a proximally hydroxyapatite-coated anatomic stem and a 28 mm standard PE liner, sterilised by gamma irradiation in air, was used in all hips. Radiological position and the possible appearance of loosening and osteolysis were recorded over time. Penetration of the prosthetic head into the liner was measured by the Roentgen Monographic Analysis (ROMAN) Tool at 6 weeks, 6 months, one year and yearly thereafter. Results. Six cups were revised due to wear and four due to late dislocation. All cups were radiographically well-fixed and all stems showed radiographic ingrowth. Six un-revised hips showed osteolysis on the acetabular side and two on the proximal femoral side. Creep at one year was 0.30 (±0.23) mm. Mean total femoral head penetration was 1.23 mm at 10 years, 1.52 mm at 15 years and 1.92 mm at 23 years. Overall mean wear was 0.12 (± 0.1) mm/year and 0.09 (±0.06) mm/year after the creep period. Mean wear was 0.08 (± 0.06) mm/year in hips without osteolysis and 0.14 (±0.03) mm/year in revised hips or with osteolysis (p<0.001). Conclusions. Although continued durable fixation can be observed with a porous-coated cups and a proximally hydroxyapatite-coated anatomic stem, true wear continues to increase at a constant level over time. PE wear remains as the main reason for revision surgery and osteolysis in uncemented THR after twenty years

Introduction. Durable bone fixation of uncemented porous-coated acetabular cups can be observed at a long-term, however, polyethylene (PE) wear and osteolysis may affect survivorship. Accurate wear measurements correlated with clinical data may offer unique research information of clinical interest about this highly debated issue. Objetive. We assessed the clinical and radiological outcome of a single uncemented total hip replacement (THR) system after twenty years analysing polyethylene wear and the appearance of osteolysis. Materials and Methods. 82 hips implanted between 1992 and 1995 were prospectively evaluated. The mean follow-up was 20.6 years (range, 18 to 23). A hemispherical porous-coated acetabular cup matched to a proximally hydroxyapatite-coated anatomic stem and a 28 mm standard PE liner, sterilised by gamma irradiation in air, was used in all hips. Radiological position and the possible appearance of loosening and osteolysis were recorded over time. Penetration of the prosthetic head into the liner was measured by the Roentgen Monographic Analysis (ROMAN) Tool at 6 weeks, 6 months, one year and yearly thereafter. Results. Six cups were revised due to wear and four due to late dislocation. All cups were radiographically well-fixed and all stems showed radiographic ingrowth. Six un-revised hips showed osteolysis on the acetabular side and two on the proximal femoral side. Creep at one year was 0.30 (±0.23) mm. Mean total femoral head penetration was 1.23 mm at 10 years, 1.52 mm at 15 years and 1.92 mm at 23 years. Overall mean wear was 0.12 (± 0.1) mm/year and 0.09 (±0.06) mm/year after the creep period. Mean wear was 0.08 (± 0.06) mm/year in hips without osteolysis and 0.14 (±0.03) mm/year in revised hips or with osteolysis (p<0.001). Conclusions. Although continued durable fixation can be observed with a porous-coated cups and a proximally hydroxyapatite-coated anatomic stem, true wear continues to increase at a constant rate over time. PE wear remains as the main reason for revision surgery and osteolysis in uncemented THR and does not stop after twenty years

We assessed the clinical and radiological outcome of a single uncemented total hip replacement (THR) after twenty years, analysing polyethylene wear and osteolysis. 82 hips implanted between 1992 and 1995 were prospectively evaluated. Mean follow-up was 20.6 years (18–23). A hemispherical porous-coated cup matched to a proximally hydroxyapatite-coated anatomic stem. A 28mm PE liner, sterilised by gamma irradiation in air, was used in all hips. Radiological position, eventual loosening and osteolysis were recorded over time. Penetration of the head into the liner was measured by the Roentgen Monographic Analysis (ROMAN) Tool at 6 weeks, 6 months, one year and yearly thereafter. Six cups were revised due to wear and four cups because of late dislocation. All stems showed osseointegration and all cups appeared radiographically well-fixed. Six unrevised hips showed osteolysis on the acetabular side and two hips on the proximal femur. Creep at one year was 0.30±0.23 mm. Mean total femoral head penetration was 1.23mm at ten years, 1.52mm at 15 years and 1.92mm at 23 years. Overall mean wear was 0.12±0.1 mm/year and 0.09±0.06 mm/year after the creep period. Mean wear was 0.08±0.06 mm/year in hips without osteolysis and 0.14±0.03 mm/year in hips revised or hips with osteolysis (p<0.001). Although continued durable fixation can be observed with porous-coated cups and proximally hydroxyapatite-coated anatomic stems, true wear continues to increase at a constant level over time. PE wear remains as the main reason for osteolysis and revision surgery in uncemented THR after twenty years

Materials & method: From July 1990 to July 1997, we reviewed 58 hips in 47 patients receiving primary cemented hip arthroplasty with porous-coated prosthesis. There were 31men and 16 women. The diagnoses included AVN of femoral head in 18, OA in 4, femoral neck fracture in 33 and RA in 3 patients. The prosthesis included PCA 17, Osteonics in 18, United in 21 and Richard in 1. Initially, all the femoral canals were prepared with the routine cementless fixation technique modified by the author (rasp-ream-rasp technique). With insertion of the final-size rasp, reliable fixation was not obtained possibly due to poor bone quality or inherent canal geometry. To avoid fracture with insertion of the next-sized stem, bone cement was added as gap-filler to augment fixation of the final-sized stems. Result: The average age of the patients at operation was 51.1 years old (range, 34 to 88). The mean follow-up was 5.8 years (range, 2 to 10). No patients were lost to follow-up. The mean Harris hip score at final F/U was 92 points. The X-rays taken postoperatively, 3months, 6months, 1 year, 2 years and the last F/U were checked carefully. Radiographically, there was no stem loosening, no measurable subsidence or demarcation line both in bone-cement and implant–cement interfaces. Even in the thinnest area of cement layer, no breakage or fracture was detected. Load transfer predominantly occurred at proximal 1/3 in 38 stems, at middle 1/3 in 20 stems (i.e. junction of porous coating and uncoated surface of the stem). No load transfer was noted at distal 1/3. Conclusion: When reliable cementless stem fixation is not obtained intraoperatively, cement can be added to function as “gap-filler” for augmenting the initial fixation. The clinical and radiological result is quite favorable. Thin (< 2mm) cement mantle between bone and porous-coated stem will not result in early cement mantle break and implant failure

Introduction. The mid- or long-term results of acetabular revision total hip arthroplasty (THA) in Korea are rare. The purpose of this study is to report the mid-term radiographic results (> 5 years) of acetabular revision THA with porous-coated cementless Trilogy. ®. cup (Zimmer, Warsaw, IN, USA). Materials and Methods. Between 1999 and 2010, 77 patients (79 hips) had underwent acetabular revision THA with Trilogy. ®. cup. Eight patients (8 hips) were excluded due to death before 5-year follow-up, and 22 patients (23 hips) were excluded due to less than 5-year follow-up or follow-up loss. Forty-seven patients (48 hips) were included in our study. The mean age was 57.9 years (range, 36 to 76 years) and the mean follow-up was 9.8 years (range 5.0 to 16.2 years). The causes of revision were aseptic loosening in 40 hips, and septic loosening in 8 hips, respectively. Both acetabular and femoral revisions were performed in 14 hips and isolated acetabular revision was done in 34 hips. Preoperetive acetabular bone defect according to Paprosky classification was; 1 in type I, 6 in IIA, 11 in IIB, 9 in IIC, 15 in IIIA, and 6 in IIIB. Results. Radiolucent lines less than 2mm were found in 2 hips; one in zone I, another in zone I, II, III. Four hips (1 in type IIC, 1 in IIIA and 2 in IIIB) showed cup migration greater than 5 mm accompanying change of position greater than 5 degrees. However, these patients did not complain pain and showed fixation by secondary stabilization. The Kaplan-Meier survivorship with aseptic loosening as the end point at 10 years was 92.6% (95% confidence interval [CI], 82.6 – 100) and at 15 years was 83.8 % (95% CI, 69.1 – 98.6), respectively. Non-recurrent dislocations occurred in 4 hips. There were no other complication such as sciatic nerve palsy, infection and deep vein thrombosis. Conclusion. Mid-term radiographic results (>5 years) of acetabular revision THA with porous-coated cementless Trilogy. ®. cup showed durable longevity. However, other options such as anti-protrusio cage or cup-cage construct should be considered in severe acetabular bone defect

Introduction: Severe stress shielding and radiographic cortical changes in the proximal femur are frequent after extensively porous-coated stem in revision surgery. We have analyzed the evolution of the femoral cortex at different levels and related factors. Material and Methods: We assessed 95 extensively porous-coated stems in revision surgery with a minimum 5-year follow-up (Mean 10.2 years). 77 hips were revised due to aseptic loosening and 18 due to periprosthetic fractures. Extended osteotomy was used in 29 hips. No cortical struts were used. Preoperative and postoperative osteoporosis was graded according to Moreland and bone defect according to Paprosky. Femoral cortex width was measured at different levels in the immediate postoperative radiograph, at 3, 6 and 12 months and at the last follow-up. Results: There were 2 re-revisions for aseptic loosening. Radiographic ingrowth fixation was more frequent in minor intraoperative bone defects (p=0.011). Preoperative osteoporosis was related to the width of the medial and lateral cortex. Medial cortical thickness increased at different levels with a mean increase of 13.4% (p< 0.001) and the lateral cortical thickness showed a mean decrease of 2.7% at the proximal level. The femoral medial cortex tended to show a higher slope trend in periprosthetic fractures (p=0.015). The outside femoral diameter increased more rapidaly with an extended trochanteric osteotomy (p=0.007). The slope trend of the lateral and medial cortex was significantly higher at proximal levels in hips with a 10-inch stem (p=0.015). Conclusions: Although without clinical relevance at the end of follow-up, femoral medial cortical thickness increased while frequently lateral cortical thickness decreased over time after an extensively porous -coated stem in revision hip surgery

Aims: The purpose of this study is to compare the clinical outcome, radiological integration and survivorship associated with a porous coated stem and those associated with a hydroxyapatite-coated stem in a consecutive serie of uncemented total hip replacements. Methods: Between 1992 and 1995, 188 primary uncemented hip arthroplasties were performed at our institution using either a proximal porous-coat or a fully HA-coated stem. Mean age and weight and distribution of sex and primary diagnosis were similar in both groups. Ninety-eight hips from the HA group (group 1) and 69 from the porous-coated group (group 2) had a complete clinical and radiographic follow-up. The average duration of follow-up period for group 1 and 2 was 10.12 and 9.8 years respectively (range,9 to 12). Parameters such as implant migration and bone remodelling were especially evaluated and compared in both groups on postoperative X-rays. Results: In group 2 , 8 hips (11.8%) needed revision for aseptic loosening and 24 additional hips (34.7%) showed non-progressive lucent lines; distal migration of the stem was seen in 9 cases(13.04%). In contrast no hip in group 1 required revision and all but two hips in this group showed radiological integration; no stem showed distal migration. Harris hip score at follow-up was better in group 1 (p= 0.05) due to a higher incidence of thigh pain in group 2 (23% vs 0%). Significant differences between both groups (p=0.02) were also observed in predicted rate of survival at 10 years with revision for aseptic loosening as the endpoint. Conclusion: In our series the HA-coated stem has provided significantly better outcomes in terms of clinical scores, radiological integration and survivorship rates than porous-coated stem

With the plasma–spray technique of applying a hydrox-ylapatite (HA) coating bone ingrowth can be enhanced and early migration of hip prostheses reduced. The significance of coating resorption is controversial. In this study the bone growth and the degradation of the HA coatings were evaluated and compared by SEM. Premature loosening was identified in four cups with an Ha coating over a porous-coated surface 3 years post-operatively.The Ha coating has a thickness of up to 50 μm. The cup specimens were soaked in 6% sodium hypochlorite to render them anorganic, dehydrated, and sputter-coated with gold-palladium. Secondary electron images of all specimens were obtained by field emission SEM (Zeiss:DSM.962). Ultrastructural analysis showed that all porous-coated Ha-coated cups had bridges of lamellar bone in direct contact with the implant surface (30% bone in-on growth). Different types of coating degradation were observed. Delamination between the coating and implant surface releases numerous particles or fragments; the resorption by osteoclasts of the amorphous phase was shown to expose the crystalline phase of the coating grains. This study suggests that resorption disintegrates the Ha coating and reduces the bonding strength between implant and bone and the strength of the coating-implant interface, which might lead to implant loosening,coating delamination and acceleration of third-body wear processes

Introduction: This study is a prospective series using a porous-coated cobalt-chromium alloy cup augmented with screw fixation for acetabular revisions. Methods: Between August 1997 and December 2001, eighty-five consecutive cementless acetabular revisions (81 patients) were performed. The mean age at operation was 64 years. Using the AAOS classification of acetabular defects there was one type I defect, 25 type two defects and 59 type III defects. Eighty-three cases were available for review (98%) with an average follow up of 6 years 6 months (range 3 months – 110 months). Clinical outcome was measured using the Charnley Hip Score and radiological assessment by plain radiographic measurement. Results: The Charnley Hip Score had improved from a pre-operative average of 7.52 (range 4–11) to the latest score of 14.84 (range 8 – 18). Significant cup migration occurred in only one case, which did not require revision. Sixteen cases demonstrated non-progressive radiolucent lines in one or two Delee and Charnley zones but none extended to all three zones. There were no cases of significant osteolysis. There were five dislocations none requiring re-operation; one revision was carried out for deep infection and one liner exchange at time of stem revision for subsidence. The results of Kaplan-Meier survival analysis using revision for all causes as the endpoint was 98.8% (95% confidence limits 0.964 to 1) at seventy-three months. Discussion: This press fit porous-coated cobalt-chromium alloy cup augmented with screw fixation for acetabular revision surgery produced excellent midterm results. Changes in cup design and material should only be undertaken with consideration of such results

Aim: Mean radiographic polyethylene wear can not distinghish between so-called Òbedding-inÒ and true wear in porous-coated cups (Sychterz 1999). Wear performance of two different generations of the same cement-less porous-coated cup are compared. Material and Methods: 83 Harris-Galante I (HGI) (32mm femoral head) and 93 Harris-Galante II (HGII) (28mm) cups are analyzed. The average follow-up was 11.5 yrs for HGPI and 6.7 years for HGPII cups. Anteroposterior pelvic radiographs (at 3 and 6 months and annually thereafter) were scanned digitally and linear wear was estimated using a software package with the Sychterz method. All radiographs were made following the same protocol. Results. Postoperative bedding-in was: 0.15±0.04 mm for HGI and 0.11±0.02 for HGII cups (p< 0.001). Femoral head penetration at the end of follow-up was: 1.50±0.28 mm for HGI and 0.85±0.01 for HGII. Mean wear excluding bedding-in was: 0.13±0.23 mm/year for HGI and 0.11±0.09 for HGII (p=0.740). The femoral head penetration rate was highest in the þrst two years and then decreased with the time and was similar in both groups. Conclusions: The digitized Sychterzñ method allows us to determine bedding-in and true polyethylene wear. The second generation cups show a decrease in the bedding-in process, but do not have a lower wear rate

Aim: To assess the long-term results of a series of porous-coated anatomic cementless total hip prostheses. Material and Methods: A total of 91 PCA (How-medica) total hip arthroplasties performed between 1984–1988 were analyzed with a mean follow-up of 13.5 years. Clinical results were assessed according to Merle DñAubignŽ-Postel score. Radiographic þxation was assessed according to Engh et al. Results:Thigh pain (17 hips) was correlated with unstable þxation (p=0.0096). Thirty-one cups and six stems were revised. Radiographic loosening ocurred in 21 cups and 12 stems. Mean polyethylene wear was 0.16 mm/year. Cup loosening was related with an acetabular wear equal to or more than 2 mm (p=0.0018) and an small cup size (p=0.015). Stem loosening was related with poor femoral canal þlling (p=0.046). Fifty (54.9%) hips had femoral osteolysis and were related with polyethylene wear of more than 2 mm (p=0.0015) and with hips with poor femoral þlling (p=0.0285) and unstable þxation (p=0.00005). Conclusions:The PCA cup has had worse results than the stem. Cup loosening is related with the acetabular wear and cup size. The frequent proximal femoral osteolysis is associated with unstable þxation and poor femoral þlling

Aims: Hydroxylapatite (HA) coating is able to enhance bone ingrowth and to reduce early migration of hip prostheses. The optimum coating quality and surface texture is still a matter of debate. Moreover, the signiþ-cance of coating resorption is controversial. In this study the degradation of the coatings HA was evaluated and comparate by SEM. Materials and methods: Four cups with HA coating over a porous-coated surface was iden-tiþed with premature loosening at 2–3 years post-operatively. The HA coating has a thickness of up to 50 μ. The cup was stored in formalin before the SEM analysis. The cup specimens was soaked in 6% sodium hypochlorite to render them anorganic, dehydrated, sputter Ð coated with gold-palladium. Secondary electron images of all specimens were obtained by þeld-emission SEM (Zeiss: DSM.962). Results: Ultrastructural analysis showed that all porous-coated HA coated cups had bridges of bone in direct contact with the implant surface (30% bone on-growth). Different types of coating degradation were observed. Delamination between the coating and implant surface; release of numerous particles or fragments ranging from a few to several dozens of microns. Under high magniþcation resorption of the amorphous phase is shown to be exposing the crystalline phase of the coating grains so that the grain boundaries become fragile and easily to be phagocytosed by osteoclasts. Conclusions: This study suggested that resorption disintegrates the HA Ð coating and reduces the bonding strength between implant and bone and the strength of the coatingÐimplant interface, which might lead to implant loosening, coating delamination and acceleration of third body wear processes

The technique for removal of bone ingrown extensively coated devices involves cutting the stem below the metaphyseal portion of the stem, followed by removal of the proximal stem and trephine removal of the cylindrical distal portion of the stem. This can be done with or without an extended trochanteric osteotomy (ETO). When the proximal portion of the stem is not bone ingrown (extensive proximal osteolysis, or the stem is broken) or the metaphyseal bone is easily accessed (there is no collar) the stem can be cut through a bone window. In all other cases an ETO at the level where the stem becomes a cylinder is required to disrupt the metaphyseal bone prosthesis interface, cut the stem and extract the proximal portion of the stem.

Glassman described the techniques for removal of cementless stems in 1992. Forty-two loose stems were easily removed, 11 fibrous stable implants were removed with thin osteotomes, and 11 bone ingrown, canal filling, extensively coated stems were removed with trephines. In no cases was reconstruction precluded by stem removal. The critical tools required included manufacturer specific removal tools, high speed burs, thin osteotomes, universal extraction device for connection to the neck, and multiple trephines.

More recently, Kancherla reported the use of trephines to remove 36 porous coated stems. Eighty-six percent of cases were bone ingrown after removal, however complications included an extruded trephine causing a femoral fracture and two periprosthetic fractures thought to be secondary to trephine induced osteonecrosis. The authors recommend bypassing the most distally trephined bone by a minimum of 4cm.

Trephines are very helpful for removing distally fixed stems. Multiple trephines need to be irrigated and changed frequently to avoid dull cutting teeth which can lead to bone necrosis.

Aims

Only a small number of studies exist that report the results of EBM-produced porous coated trabecular titanium cups in primary total hip arthroplasty (THA). This study aims to investigate the patient satisfaction level, clinical function and radiographic outcomes of the patients who underwent THA using an EBM-produced porous coated titanium cup.

Introduction: Total hip arthroplasty remains an effective tool for the treatment of patients with end-stage osteonecrosis with collapse of the femoral head, although there is an increased risk for failure. The aim of this study was to assess the clinical and radiographic outcome of the cementless femoral component with a circumferentially porous coated design.

Materials and Methods: Sixty-four total hip arthroplasties in 53 patients with osteonecrosis of the femoral head were available for evaluation after a 5–10 year follow-up period (average, 7 years). The average age at surgery was 48 years (range, 25–66 years). Osteonecrosis etiology was alcohol induced in 31 hips, idiopathic in 21, steroid related in 5, and femoral neck fracture in 7. A cementless Harris-Galante II cup and Multilock cementless femoral stem with circumferentially porous coating in the proximal part were used in all patients.

Results: Average Harris hip scores improved from 51.6 points to 86.6 points. Thigh pain was noticed in 6 hips (9.4%) at the latest follow up. Most of the thigh pain was related to the diffuse osteolysis with stem instability. At the latest follow up, 58 stems (90.6%) displayed stable bony fixation, one (1.6%) fibrous fixation, and five (7.8%) unstable fixation. Twenty-four hips (37.5%) revealed osteolysis mostly in Zones I and VII. Five hips (7.8%) exhibited distal osteolysis. Five hips (7.8%) exhibited mechanical failure of the stem usually associated with the diffuse osteolysis around the stem. The authors have also observed increased polyethylene line wear (annual wear rate = 0.39 mm / year)

Discussion: The increased polyethylene wear may be due to a weaker polyethylene interlocking mechanism of Harris-Galante II cup, a young active age population of osteonecrosis, inadequate polyethylene liner thickness, and frequent sitting cross legged in a non-western population. The midterm results using the circumferentially porous coated stem showed favorable bony ingrowth. Osteolytic lesions were primary limited to proximal Zones I and VII even with increased polyethylene wear particle formation and increased osteolytic lesions in Harris-Galante II cup designs. This may be due to the excellent circumferential osteointegration into the proximal part of the stem.

Introduction

Fixation has been shown to be the primary indicator of an implant's long-term success. Failure to achieve attachment, especially in acetabular and TKR, has been attributed to a lack of initial stability and gaps between the implant and bone. Gaps greater than 150 microns allow fibrous tissue to form. Properly addressing implant design features can help avoid adverse outcomes.

ASTM International Standards (F1854-09) do not assess the relationship between porosity of the coating and that of cancellous bone, which can lead to an absence of mechanical interlock. This study developed a virtual program that uses human cancellous bone to predict potential skeletal attachment for implants properly placed for TJR. The goal of the Virtual Paradigm was to assess initial contact surface area at the time of implantation.

Background: The purpose of this systematic review was to determine the clinical and radiologic benefit of hydroxyapatite-coating in uncemented primary total hip arthroplasty.

Methods: A database of Medline articles published up to september 2007 was compiled and relevant references screened. Studies that satisfied the following selection criteria were included:

a proper randomized controlled trial;

Results: Eight studies, involving 857 patients, were included in the review. Observer agreement was 94%, while the interobserver reliability was K =.799 (.611 −.987); P < 0.001. Pooled analysis for Harris Hip Score as a clinical outcome measure demonstated no advantage of the hydroxyapatite coating (WMD: 1.49, CI: −2.32 to 5.31, P = 0.44). Radiologically, both groups showed equal presence of endosteal bone ingrowth (RR: 1.04, CI: 0.88 to 1.23, P = 0.66) and radio-active lines (RR: 1.02, CI: 0.90 to 1.16, P = 0.74) in the surface area of the prosthesis. Pooling on stem subsidence was not feasible, because three different measurement techniques were used.

Conclusion: Based on eight randomized controlled trials, this meta-analysis demonstrates no clinical nor radiological benefits to the application of a hydroxy-apatite coating on a femoral component in uncemented primary total hip arthroplasty.

We report the results of a cementless modular revision component which has been used in our hospital since 1993. There were 103 patients, in which the aforementioned cementless femoral revision component was used. Patients were evaluated, using both a modiþed HHS and serial radiographs performed preoperatively, at 2 weeks, 3 months and annually postoperatively. The patients were followed for a minimum of 4 years. Pre-operatively, bony defects were classiþed on radiographs according to the classiþcation of Mallory. Three hips were excluded from the evaluation: 1 was lost to follow-up and 2 were deceased. 100 hips with an average follow-up of 75 months were retrospectively reviewed. Indication for revision was aseptic loosening in 96 cases and infection in 4. Average number of previous hip surgeries in this patient group was 2.3. Average pre-operative hip score was 48,8 compared to an average postoperative hip score of 74,4. Postoperative complications included 2 infections and 2 cases of DVT with occurrence of PE in 1 case, 4 postoperative dislocations, 2 cases with radiographic subsidence of the femoral component and 1 case with sciatic nerve lesion. Intraoperative complications included femoral fractures upon dislocation of the hip or impaction of the new stem in 37 cases. At time of latest review there were no clinical or radiographic signs of component loosening. The incidence of postoperative and intraoperative complications are comparable to the literature. Clinical and radiographic results of the cementless, modular titanium revision component are promising and support its continued use.

The use of cementless acetabular components is currently the gold standard for treatment in total hip arthroplasty (THA). Porous coated cups have a low modulus of elasticity that enhances press-fit and a surface that promotes osseointegration. Monoblock acetabular cups represent a subtype of uncemented cup with the liner moulded into the metal shell, minimizing potential backside wear and eliminating the chance of mal-seating. The aim of this study was to compare the short-term clinical and radiographic performances of a modular cup with that of a monoblock cup, with particular interest in the advent of lucent lines and their correlation with clinical outcomes. In this multi-surgeon, prospective, randomized, controlled trial, 86 patients undergoing unilateral THA were recruited. Participants were randomized to either a porous-coated, modular metal-on-polyethylene (MoP) acetabular component (n=46) or a hydroxyapatite (HA)- and titanium-coated monoblock shell with ceramic-on-ceramic (CoC) bearing (n=42). The porous-coated cup had an average pore size of 250 microns with an average volume porosity of 45%, whereas the monoblock shell had an average pore size of 300 microns with an average volume porosity of 48% and a HA coating thickness of 80 nm. There were no baseline demographic differences between both groups regarding sex, age, body mass index (BMI), or American Society of Anaesthesia (ASA) class (p>0.05). All of the sockets were under-reamed by 1 mm. Radiographs and patient-reported outcome measures (PROMs), including modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and University of California at Los Angeles (UCLA) Hip Score, were available for evaluation at a minimum of 2 years of follow-up. A radiolucent distance between the cup and acetabulum of ≥0.5 mm was defined as gap if it was diagnosed from outset or as radiolucency if it had sclerotic edges and was found on progressive x-ray analyses. Thirty-two gaps (69%) were found in the modular cup group and 28 (6%) in the monoblock one (p=0.001). Of the former, 17 filled the gaps whereas 15 turned into a radiolucency at final assessment. Of the latter, only 1 of the gaps turned into a radiolucency at final follow-up (p 0.05) in both groups. Only the porous-coated cup was an independent predictor of lucent lines (OR:0.052, p=0.007). No case underwent revision surgery due to acetabular loosening during the study period. Only 2 cases of squeaking were reported in the CoC monoblock shell. Both porous-coated modular and hydroxyapatite-coated monoblock cups showed successful clinical results at short-term follow-up, however, the former evidenced a significantly higher rate of radiolucent line occurrence, without any association with PROMs. Since these lines indicate the possibility of future cup loosening, longer follow-up and assessment are necessary