Advertisement for orthosearch.org.uk
Results 41 - 60 of 166
Results per page:
The Bone & Joint Journal
Vol. 99-B, Issue 4_Supple_B | Pages 27 - 32
1 Apr 2017
Cnudde PHJ Kärrholm J Rolfson O Timperley AJ Mohaddes M

Aims. Compared with primary total hip arthroplasty (THA), revision surgery can be challenging. The cement-in-cement femoral revision technique involves removing a femoral component from a well-fixed femoral cement mantle and cementing a new stem into the original mantle. This technique is widely used and when carried out for the correct indications, is fast, relatively inexpensive and carries a reduced short-term risk for the patient compared with the alternative of removing well-fixed cement. We report the outcomes of this procedure when two commonly used femoral stems are used. Patients and Methods. We identified 1179 cement-in-cement stem revisions involving an Exeter or a Lubinus stem reported to the Swedish Hip Arthroplasty Register (SHAR) between January 1999 and December 2015. Kaplan-Meier survival analysis was performed. Results. Survivorship is reported up to six years and was better in the Exeter group (91% standard deviation (. sd). 2.8% versus 85% . sd. 5.0%) (p = 0.02). There was, however, no significant difference in the survival of the stem and risk of re-revision for any reason (p = 0.58) and for aseptic loosening (p = 0.97), between revisions in which the Exeter stem (94% . sd. 2.2%; 98% . sd. 1.6%) was used compared with those in which the Lubinus stem (95% . sd. 3.2%; 98% . sd.  2.2%) was used. The database did not allow identification of whether a further revision was indicated for loosening of the acetabular or femoral component or both. Conclusion. The cement-in-cement technique for revision of the femoral component gave promising results using both designs of stem, six years post-operatively. Cite this article: Bone Joint J 2017;99-B(4 Supple B):27–32


The Bone & Joint Journal
Vol. 102-B, Issue 12 | Pages 1682 - 1688
1 Dec 2020
Corona PS Vicente M Carrera L Rodríguez-Pardo D Corró S

Aims

The success rates of two-stage revision arthroplasty for infection have evolved since their early description. The implementation of internationally accepted outcome criteria led to the readjustment of such rates. However, patients who do not undergo reimplantation are usually set aside from these calculations. The aim of this study was to investigate the outcomes of two-stage revision arthroplasty when considering those who do not undergo reimplantation, and to investigate the characteristics of this subgroup.

Methods

A retrospective cohort study was conducted. Patients with chronic hip or knee periprosthetic joint infection (PJI) treated with two-stage revision between January 2010 and October 2018, with a minimum follow-up of one year, were included. Variables including demography, morbidity, microbiology, and outcome were collected. The primary endpoint was the eradication of infection. Patients who did not undergo reimplantation were analyzed in order to characterize this subgroup better.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 9 | Pages 1143 - 1148
1 Sep 2006
Hallan G Aamodt A Furnes O Skredderstuen A Haugan K Havelin LI

We performed a randomised, radiostereometric study comparing two different bone cements, one of which has been sparsely clinically documented. Randomisation of 60 total hip replacements (57 patients) into two groups of 30 was undertaken. All the patients were operated on using a cemented Charnley total hip replacement, the only difference between groups being the bone cement used to secure the femoral component. The two cements used were Palamed G and Palacos R with gentamicin. The patients were followed up with repeated clinical and radiostereometric examinations for two years to assess the micromovement of the femoral component and the clinical outcome. The mean subsidence was 0.18 mm and 0.21 mm, and the mean internal rotation was 1.7° and 2.0° at two years for the Palamed G and Palacos R with gentamicin bone cements, respectively. We found no statistically significant differences between the groups. Micromovement occurred between the femoral component and the cement, while the cement mantle was stable inside the bone. The Harris hip score improved from a mean of 38 points (14 to 54) and 36 (10 to 57) pre-operatively to a mean of 92 (77 to 100) and 91 (63 to 100) at two years in the Palamed G and Palacos R groups, respectively. No differences were found between the groups. Both bone cements provided good initial fixation of the femoral component and good clinical results at two years


Bone & Joint 360
Vol. 9, Issue 5 | Pages 4 - 9
1 Oct 2020
Matthews E Waterson HB Phillips JR Toms AD


The Bone & Joint Journal
Vol. 102-B, Issue 8 | Pages 965 - 966
1 Aug 2020
Haddad FS Plastow R


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 71 - 78
1 Jan 2021
Maggs JL Swanton E Whitehouse SL Howell JR Timperley AJ Hubble MJW Wilson MJ

Aims. Periprosthetic fractures (PPFs) around cemented taper-slip femoral prostheses often result in a femoral component that is loose at the prosthesis-cement interface, but where the cement-bone interface remains well-fixed and bone stock is good. We aim to understand how best to classify and manage these fractures by using a modification of the Vancouver classification. Methods. We reviewed 87 PPFs. Each was a first episode of fracture around a cemented femoral component, where surgical management consisted of revision surgery. Data regarding initial injury, intraoperative findings, and management were prospectively collected. Patient records and serial radiographs were reviewed to determine fracture classification, whether the bone cement was well fixed (B2W) or loose (B2L), and time to fracture union following treatment. Results. In total, 47 B2W fractures (54.0%) and one B3 fracture (1.1%) had cement that remained well-fixed at the cement-bone interface. These cases were treated with cement-in-cement (CinC) revision arthroplasty. Overall, 43 fractures with follow-up united, and two patients sustained further fractures secondary to nonunion and required further revision surgery. A total of 19 B2L fractures (21.8%) and 19 B3 fractures (21.8%) had cement that was loose at the cement-bone interface. These cases were managed by revision arthroplasty with either cemented or uncemented femoral components, or proximal femoral arthroplasty. One case could not be classified. Conclusion. We endorse a modification of the original Vancouver system to include a subclassification of B2 fractures around cemented femoral prostheses to include B2W (where cement is well-fixed to bone) and B2L (where the cement is loose). Fractures around taper-slip design stems are more likely to fracture in a B2W pattern compared to fractures around composite beam design stems which are more likely to fracture in a B2L pattern. B2W fractures can reliably be managed with CinC revision. Cite this article: Bone Joint J 2021;103-B(1):71–78


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 98 - 104
1 Jan 2021
van Ooij B Sierevelt IN van der Vis HM Hoornenborg D Haverkamp D

Aims. For many designs of total knee arthroplasty (TKA) it remains unclear whether cemented or uncemented fixation provides optimal long-term survival. The main limitation in most studies is a retrospective or non-comparative study design. The same is true for comparative trials looking only at the survival rate as extensive sample sizes are needed to detect true differences in fixation and durability. Studies using radiostereometric analysis (RSA) techniques have shown to be highly predictive in detecting late occurring aseptic loosening at an early stage. To investigate the difference in predicted long-term survival between cemented, uncemented, and hybrid fixation of TKA, we performed a randomized controlled trial using RSA. Methods. A total of 105 patients were randomized into three groups (cemented, uncemented, and hybrid fixation of the ACS Mobile Bearing (ACS MB) knee system, implantcast). RSA examinations were performed on the first day after surgery and at scheduled follow-up visits at three months, six months, one year, and two years postoperatively. Patient-reported outcome measures (PROMs) were obtained preoperatively and after two years follow-up. Patients and follow-up investigators were blinded for the result of randomization. Results. RSA secondary stabilization did not show a significant difference between the three types of fixation. A maximum total point motion of less than 0.2 mm in the second postoperative year was shown in each group, which suggests stabilization of the implant. At 24 months after surgery, PROMs significantly improved compared to baseline in all treatment groups. No significant difference was observed between the three groups. Conclusion. Secondary stabilization measurements in this study demonstrated no significant difference between the groups. In all groups migration stabilized after initial settling of the implant. For this implant the long-term outcome is not expected to be influenced by the type of fixation to the bone. Cite this article: Bone Joint J 2021;103-B(1):98–104


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 7 - 15
1 Jan 2021
Farhan-Alanie MM Burnand HG Whitehouse MR

Aims. This study aimed to compare the effect of antibiotic-loaded bone cement (ALBC) versus plain bone cement (PBC) on revision rates for periprosthetic joint infection (PJI) and all-cause revisions following primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. MEDLINE, Embase, Web of Science, and Cochrane databases were systematically searched for studies comparing ALBC versus PBC, reporting on revision rates for PJI or all-cause revision following primary elective THA or TKA. A random-effects meta-analysis was performed. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42018107691). Results. Nine studies and one registry report were identified, enabling the inclusion of 371,977 THA and 671,246 TKA. Pooled analysis for THA demonstrated ALBC was protective against revision for PJI compared with PBC (relative risk (RR) 0.66, 95% confidence interval (CI) 0.56 to 0.77; p < 0.001), however, no differences were seen for all-cause revision rate (RR 0.62, 95% CI 0.35 to 1.09; p = 0.100). For TKA, there were no significant differences in revision rates for PJI or all causes between ALBC and PBC (RR 0.92, 95% CI 0.59 to 1.45; p = 0.730, and RR 0.73, 95% CI 0.53 to 1.02; p = 0.060, respectively). Conclusion. ALBC demonstrated a protective effect against revision for PJI compared with PBC in THA with no difference in all-cause revisions. No differences in revision rates for PJI and all-cause revision between ALBC and PBC for TKA were observed. Cite this article: Bone Joint J 2021;103-B(1):7–15


Bone & Joint Research
Vol. 9, Issue 12 | Pages 884 - 893
1 Dec 2020
Guerado E Cano JR Pons-Palliser J

Aims

A systematic literature review focusing on how long before surgery concurrent viral or bacterial infections (respiratory and urinary infections) should be treated in hip fracture patients, and if there is evidence for delaying this surgery.

Methods

A total of 11 databases were examined using the COre, Standard, Ideal (COSI) protocol. Bibliographic searches (no chronological or linguistic restriction) were conducted using, among other methods, the Patient, Intervention, Comparison, Outcome (PICO) template. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for flow diagram and checklist. Final reading of the complete texts was conducted in English, French, and Spanish. Classification of papers was completed within five levels of evidence (LE).


The Bone & Joint Journal
Vol. 102-B, Issue 10 | Pages 1319 - 1323
3 Oct 2020
Khatun F Gill DF Atrey A Porteous M

Aims. We present the results, in terms of survival, clinical outcome, and radiological appearance at 20 years, in a cohort of 225 cemented Exeter Universal femoral components (Stryker, Newbury, UK) implanted in 207 patients, at a district general hospital. Methods. All patients in this study had a total hip arthroplasty (THA) using an Exeter Universal femoral component with a cemented (n = 215) or cementless (n = 10) acetabular component. Clinical and radiological data were collected prospectively at one year, five years, and every five years thereafter. Patients lost to radiological and clinical follow-up (five) were cross-referenced with National Joint Registry (NJR) data and general practitioner (GP) records to assess whether they had undergone revision for any reason. Results. During this period of study 144 patients (157 hips) died (69.78%). Two patients were lost to follow-up, leaving 61 patients (66 hips) available for review (29.33%). Of the 225 hips, three underwent revision for femoral failure with osteolysis. One underwent femoral component revision for treatment of a periprosthetic fracture. Eight underwent revision of the acetabular component only for loosening. Two hips had both components revised, when components were found to be loose at time of revision for acetabular loosening, though no radiological femoral osteolysis. Two patients underwent revision for infection. Using femoral loosening as an endpoint, the survival of the Exeter Universal femoral component was 98.7% (n = 220, 95% confidence interval (CI) 96.1% to 100%) at 20 to 22 years. Survival with an endpoint of revision for any reason was 92.6% (n = 209, 95% CI 89.4 to 95.55), with a ‘worst-case scenario’ (considering two patients lost to follow-up to have failed), the overall survival rate was 91.7% (n = 207, 95% CI 87.8 to 95.9) at 20 to 22 years. Conclusion. Our results confirm excellent long-term results for the cemented Exeter Universal femoral componentimplanted outside of the originating centre. Cite this article: Bone Joint J 2020;102-B(10):1319–1323


The Bone & Joint Journal
Vol. 101-B, Issue 9 | Pages 1107 - 1114
1 Sep 2019
Uy M Wang J Horner NS Bedi A Leroux T Alolabi B Khan M

Aims. The aim of this study was to evaluate the differences in revision and complication rates, functional outcomes, and radiological outcomes between cemented and press-fit humeral stems in primary anatomical total shoulder arthroplasty (TSA). Materials and Methods. A comprehensive systematic review and meta-analysis was conducted searching for studies that included patients who underwent primary anatomical TSA for primary osteoarthritis or rheumatoid arthritis. Results. There was a total of 36 studies with 927 cemented humeral stems and 1555 press-fit stems. The revision rate was 5.4% (95% confidence interval (CI) 3.9 to 7.4) at a mean of 89 months for cemented stems, and 2.4% (95% CI 1.1 to 4.7) at a mean of 40 months for press-fit stems. A priori subgroup analysis to control for follow-up periods demonstrated similar revision rates: 2.3% (95% CI 1.1 to 4.7) for cemented stems versus 1.8% (95% CI 1.4 to 2.9) for press-fit stems. Exploratory meta-regression found that longer follow-up was a moderating variable for revision (p = 0.003). Conclusion. Cement fixation had similar revision rates when compared to press-fit stems at short- to midterm follow-up. Rotator cuff pathology was a prevalent complication in both groups but is likely not related to fixation type. Overall, with comparable revision rates, possible easier revision, and decreased operative time, humeral press-fit fixation may be an optimal choice for primary anatomical TSA in patients with sufficient bone stock. Cite this article: Bone Joint J 2019;101-B:1107–1114


Bone & Joint Research
Vol. 4, Issue 3 | Pages 29 - 37
1 Mar 2015
Halim T Clarke IC Burgett-Moreno MD Donaldson TK Savisaar C Bowsher JG

Objectives. Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt–chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA). Methods. Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range 5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments (5 mg) were inserted at ten intervals during the five million cycle (5 Mc) test. . Results. In a clean test phase (0 Mc to 0.8 Mc), lubricants retained their yellow colour. Addition of metal particles at 0.8 Mc turned lubricants black within the first hour of the test and remained so for the duration, while PMMA particles did not change the colour of the lubricant. Rates of wear with PMMA, CoCr and Ti6Al4V debris averaged 0.3 mm. 3. /Mc, 4.1Â mm. 3. /Mc and 6.4 mm. 3. /Mc, respectively. . Conclusions. Metal particles turned simulator lubricants black with rates of wear of MOM bearings an order of magnitude higher than with control PMMA particles. This appeared to model the findings of black, periarticular joint tissues and high CoCr wear in failed MOM replacements. The amount of wear debris produced during a 500 000-cycle interval of gait was 30 to 50 times greater than the weight of triggering particle allotment, indicating that MOM bearings were extremely sensitive to third-body wear. Cite this article: Bone Joint Res 2015;4:29–37


The Bone & Joint Journal
Vol. 102-B, Issue 6 Supple A | Pages 151 - 157
1 Jun 2020
Gil D Atici AE Connolly RL Hugard S Shuvaev S Wannomae KK Oral E Muratoglu OK

Aims. We propose a state-of-the-art temporary spacer, consisting of a cobalt-chrome (CoCr) femoral component and a gentamicin-eluting ultra-high molecular weight polyethylene (UHMWPE) tibial insert, which can provide therapeutic delivery of gentamicin, while retaining excellent mechanical properties. The proposed implant is designed to replace conventional spacers made from bone cement. Methods. Gentamicin-loaded UHMWPE was prepared using phase-separated compression moulding, and its drug elution kinetics, antibacterial, mechanical, and wear properties were compared with those of conventional gentamicin-loaded bone cement. Results. Gentamicin-loaded UHMWPE tibial components not only eradicated planktonic Staphylococcus aureus, but also prevented colonization of both femoral and tibial components. The proposed spacer possesses far superior mechanical and wear properties when compared with conventional bone cement spacers. Conclusion. The proposed gentamicin-eluting UHMWPE spacer can provide antibacterial efficacy comparable with currently used bone cement spacers, while overcoming their drawbacks. The novel spacer proposed here has the potential to drastically reduce complications associated with currently used bone cement spacers and substantially improve patients’ quality of life during the treatment. Cite this article: Bone Joint J 2020;102-B(6 Supple A):151–157


The Bone & Joint Journal
Vol. 102-B, Issue 6 Supple A | Pages 107 - 115
1 Jun 2020
Tetreault MW Perry KI Pagnano MW Hanssen AD Abdel MP

Aims

Metaphyseal fixation during revision total knee arthroplasty (TKA) is important, but potentially difficult when using historical designs of cone. Material and manufacturing innovations have improved the size and shape of the cones which are available, and simplified the required bone preparation. In a large series, we assessed the implant survivorship, radiological results, and clinical outcomes of new porous 3D-printed titanium metaphyseal cones featuring a reamer-based system.

Methods

We reviewed 142 revision TKAs in 139 patients using 202 cones (134 tibial, 68 femoral) which were undertaken between 2015 and 2016. A total of 60 involved tibial and femoral cones. Most cones (149 of 202; 74%) were used for Type 2B or 3 bone loss. The mean age of the patients was 66 years (44 to 88), and 76 (55 %) were female. The mean body mass index (BMI) was 34 kg/m2 (18 to 60). The patients had a mean of 2.4 (1 to 8) previous operations on the knee, and 68 (48%) had a history of prosthetic infection. The mean follow-up was 2.4 years (2 to 3.6).


The Bone & Joint Journal
Vol. 102-B, Issue 4 | Pages 458 - 462
1 Apr 2020
Limberg AK Tibbo ME Pagnano MW Perry KI Hanssen AD Abdel MP

Aims. Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs. Methods. A total of 416 consecutive revision TKAs (398 patients) were performed at our institution using a single fixed-bearing VVC TKA from 2007 to 2015. Mean age was 64 years (33 to 88) with 50% male (199). Index revision TKA diagnoses were: instability (n = 122, 29%), aseptic loosening (n = 105, 25%), and prosthetic joint infection (PJI) (n = 97, 23%). All devices were cemented on the epiphyseal surfaces. Femoral stems were used in 97% (n = 402) of cases, tibial stems in 95% (n = 394) of cases; all were cemented. In total, 93% (n = 389) of cases required a stemmed femoral and tibial component. Femoral cones were used in 29%, and tibial cones in 40%. Survivorship was assessed via competing risk analysis; clinical outcomes were determined using Knee Society Scores (KSSs) and range of movement (ROM). Mean follow-up was four years (2 to 10). Results. The five-year cumulative incidence of subsequent revision for aseptic loosening and instability were 2% (95% confidence interval (CI) 0.2 to 3, number at risk = 154) and 4% (95% CI 2 to 6, number at risk = 153), respectively. The five-year cumulative incidence of any subsequent revision was 14% (95% CI 10 to 18, number at risk = 150). Reasons for subsequent revision included PJI (n = 23, of whom 12 had previous PJI), instability (n = 13), and aseptic loosening (n = 11). The use of this implant without stems was found to be a significant risk factor for subsequent revision (hazard ratio (HR) 7.58 (95% CI 3.98 to 16.03); p = 0.007). KSS improved from 46 preoperatively to 81 at latest follow-up (p < 0.001). ROM improved from 96° prerevision to 108° at latest follow-up (p = 0.016). Conclusion. The cumulative incidence of subsequent revision for aseptic loosening and instability was very low at five years with this fixed-bearing VVC implant in revision TKAs. Routine use of cemented and stemmed components with targeted use of metaphyseal cones likely contributed to this low rate of aseptic loosening. Cite this article: Bone Joint J 2020;102-B(4):458–462


Bone & Joint Research
Vol. 9, Issue 4 | Pages 162 - 172
1 Apr 2020
Xie S Conlisk N Hamilton D Scott C Burnett R Pankaj P

Aims. Metaphyseal tritanium cones can be used to manage the tibial bone loss commonly encountered at revision total knee arthroplasty (rTKA). Tibial stems provide additional fixation and are generally used in combination with cones. The aim of this study was to examine the role of the stems in the overall stability of tibial implants when metaphyseal cones are used for rTKA. Methods. This computational study investigates whether stems are required to augment metaphyseal cones at rTKA. Three cemented stem scenarios (no stem, 50 mm stem, and 100 mm stem) were investigated with 10 mm-deep uncontained posterior and medial tibial defects using four loading scenarios designed to mimic activities of daily living. Results. Small micromotions (mean < 12 µm) were found to occur at the bone-implant interface for all loading cases with or without a stem. Stem inclusion was associated with lower micromotion, however these reductions were too small to have any clinical significance. Peak interface micromotion, even when the cone is used without a stem, was too small to effect osseointegration. The maximum difference occurred with stair descent loading. Stress concentrations in the bone occurred around the inferior aspect of each implant, with the largest occurring at the end of the long stem; these may lead to end-of-stem pain. Stem use is also found to result in stress shielding in the bone along the stem. Conclusion. When a metaphyseal cone is used at rTKA to manage uncontained posterior or medial defects of up to 10 mm depth, stem use may not be necessary. Cite this article:Bone Joint Res. 2020;9(4):162–172


Bone & Joint Research
Vol. 8, Issue 12 | Pages 604 - 607
1 Dec 2019
Konan S Abdel MP Haddad FS

There is continued debate as to whether cemented or cementless implants should be utilized in particular cases based upon chronological age. This debate has been rekindled in the UK and other countries by directives mandating certain forms of acetabular and femoral component fixation based exclusively on the chronological age of the patient. This editorial focuses on the literature-based arguments to support the use of cementless total hip arthroplasty (THA), while addressing potential concerns surrounding safety and cost-effectiveness. Cite this article: Bone Joint Res. 2019;8(12):604–607


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 1 | Pages 31 - 36
1 Jan 2009
de Jong PT de Man FHR Haverkamp D Marti RK

We report the long-term outcome of a modified second-generation cementing technique for fixation of the acetabular component of total hip replacement. An earlier report has shown the superiority of this technique assessed by improved survival compared with first-generation cementing. The acetabular preparation involved reaming only to the subchondral plate, followed by impaction of the bone in the anchorage holes. Between 1978 and 1993, 287 total hip replacements were undertaken in 244 patients with a mean age of 65.3 years (21 to 90) using a hemispherical Weber acetabular component with this modified technique for cementing and a cemented femoral component. The survival with acetabular revision for aseptic loosening as the endpoint was 99.1% (95% confidence interval 97.9 to 100 after ten years and 85.5% (95% confidence interval 74.7 to 96.2) at 20 years. Apart from contributing to a long-lasting fixation of the component, this technique also preserved bone, facilitating revision surgery when necessary


The Bone & Joint Journal
Vol. 101-B, Issue 12 | Pages 1557 - 1562
1 Dec 2019
Tillman R Tsuda Y Puthiya Veettil M Young PS Sree D Fujiwara T Abudu A

Aims

The aim of this study was to present the long-term surgical outcomes, complications, implant survival, and causes of implant failure in patients treated with the modified Harrington procedure using antegrade large diameter pins.

Patients and Methods

A cohort of 50 consecutive patients who underwent the modified Harrington procedure for periacetabular metastasis or haematological malignancy between January 1996 and April 2018 were studied. The median follow-up time for all survivors was 3.2 years (interquartile range 0.9 to 7.6 years).


The Journal of Bone & Joint Surgery British Volume
Vol. 86-B, Issue 5 | Pages 771 - 776
1 Jul 2004
Frei H Mitchell P Masri BA Duncan CP Oxland TR

We studied various aspects of graft impaction and penetration of cement in an experimental model. Cancellous bone was removed proximally and local diaphyseal lytic defects were simulated in six human cadaver femora. After impaction grafting the specimens were sectioned and prepared for histomorphometric analysis. The porosity of the graft was lowest in Gruen zone 4 (52%) and highest in Gruen zone 1 (76%). At the levels of Gruen zones 6 and 2 the entire cross-section was almost filled with cement. Cement sometimes reached the endosteal surface in other Gruen zones. The mean peak impaction forces exerted with the impactors were negatively correlated with the porosity of the graft