Background

Ankle and hindfoot fusion in the presence of large bony defects represents a challenging problem. Treatment options include acute shortening and fusion or void filling with metal cages or structural allograft, which both have historically low union rates. Impaction grafting is an alternative option.

Objective

The purpose of this study was to determine the outcomes of revision ankle replacements, using the Invision implant and impaction allograft for massive talar dome defects following primary ankle replacement failure. Outcomes were assessed in terms of bone graft incorporation; improvement in patient reported outcome measures (PROMs); and survivorship of the revision ankle arthroplasty.

Trabecular metal (TM) augments are designed to support an uncemented socket in revision surgery when adequate rim fit is not possible. We have used TM augments in an alternative arrangement, to contain segmental defects to facilitate impaction bone grafting (IBG) and cementation of a cemented socket. However, there is a paucity of literature supporting the use of this technique. We present one of the largest studies to date, reporting early outcomes of patients from a tertiary centre.

A single-centre retrospective analytical study of prospectively collected data was performed on patients who had undergone complex acetabular reconstruction using TM augments, IBG and a cemented cup. All patients operated between 2015 and 2019 were included. We identified 105 patients with a mean age of 74yrs. The mean follow-up was 2.3 years(1–5.5yrs). Our primary outcome measure was all-cause revision of the construct. The secondary outcome measures were, Oxford hip score (OHS), radiographic evidence of cup migration/loosening and post-op complications.

Eighty-four out of 105 patients belonged to Paprosky grade IIb, IIc or IIIa. Kaplan-Meier survivorship for all-cause revision was 96.36% (CI, 90.58–100.00) at 2 years with 3 failures. Two were due to early infection which required two-stage re-revision. The third was due to post-operative acetabular fracture which was then re-revised with TM augment, bone graft and large uncemented cup. Pre-op and post-op matched OHS scores were available for 60 hips(57%) with a mean improvement of 13 points. Radiographic analysis showed graft incorporation in all cases with no evidence of cup loosening. The mean vertical cup migration was 0.5mm (Range −5 to 7mm). No other complications were recorded.

This study shows that reconstruction of large acetabular defects during revision THA using a combination of TM augments to contain the acetabulum along with IBG to preserve the bone stock and a cemented socket is a reliable and safe technique with low revision rates and satisfactory clinical and radiographic results. Long term studies are needed to assess the possibility of preservation and regeneration of bone stock.

Femoral impaction bone grafting (IBG) may be used to restore bone stock in revision total hip arthroplasty (THA) and allow use of a shorter, than otherwise, length prosthesis. This is most beneficial in young patients who are more likely to require further revision surgery. This study aimed to assess the results of femoral IBG for staged revision THA for infection. A prospective cohort of 29 patients who underwent staged revision THA for infection with femoral IBG and a cemented polished double-tapered (CPDT) stem at the final reconstruction was investigated.

The minimum follow-up was two years (2 – 10 years, median 6 years). Stem subsidence was measured with radiostereometric analysis. Clinical outcomes were assessed with the Harris Hip, Harris Pain, and and Société Internationale de Chirurgie Orthopédique et de Traumatologie Activity (SICOT) Scores. The original infection was eradicated in 28 patients. One patient required a repeat staged revision due to re-infection with the same organism. At two-year follow-up, the median subsidence at the stem-bone interface was −1.70 mm (−0.31 to −4.98mm). The median Harris Hip Score improved from 51 pre-operatively to 80 at two years (p=0.000), the Harris Pain Score from 20 to 44 (p=0.000) and the SICOT Score from 2.5 to 3 (p=0.003).

As successful eradication of infection was achieved in the majority of patients and the stem migration was similar to that of a primary CPDT stem, this study supports the use of femoral IBG during the final reconstruction of the femur after staged revision THA for infection.

Introduction

Biological repair of acetabular bone defects after impaction bone grafting (IBG) in total hip arthroplasty could facilitate future re-revisions in case of failure of the reconstruction again using the same technique. Few studies have analysed the outcome of these acetabular re-revisions.

Introduction. Periprosthetic joint infection (PJI) represents the costliest complication in Orthopedics. Studies of mixing vancomycin to bone graft at Impaction Bone Grafting (IBG) have shown high local concentration for 3 weeks. Patients and methods. 55 consecutive revisions PJI, age 68 (SD 10.9), (9 one-stage and 46 two-stage) were retrospectively analyzed. All cases were revised using IBG. Most cases had vancomycin mixed in graft or added locally in joint. All had bone cement containing Gentamycin and Vancomycin. Follow up 2–16 years included clinical Merle d'Aubigne-Postel score, radiology and laboratory tests. We analyzed surgical time, bleeding, hospitalization time, infection eradication and prosthetic survival for one- and two-stage revision procedures. One patient was lost to follow up and 6 died (2 one- and 4 2-stage) before 2 years. Values are mean and SD. Analyses done by students t-test. Results. Preoperatively scores for 1- and 2-stage groups were 11.7 (0.79) and 10.2 (1.27) respectively. Follow up scores were 17.5 (0.38) and 15.9 (0.73) respectively. Total intra-operative blood loss (ml) for one- and two-stage procedures were 1638 (780) and 2764 (828) respectively p<0.05. Total surgery time (minutes): 238 (206) and 409 (108) respectively p<0.05. Total hospitalization time (days): 13 (6.2) and 34 (13) p<0.05. Radiology at follow-up showed no signs of PJI, signs of mechanical loosening in one. There were no persistent or new PJI, no revision for mechanical loosening. Two revision for any reason in the 2-stage and one in the 1-stage group. Five reoperations without component exchange for periprosthetic fracture, all in the 2-stage group. Conclusion. No mechanical loosening and no persistent or new PJI are favourable results. Blood loss, hospitalization- and surgery-time were substantially increased for the two-stage group. Muscle atrophy, osteoporotic development and decrease general physical condition are all well-known side effects of two-stage procedure. Revision one-stage hip PJI using IBG avoids increased suffering and resources connected to the two-stage procedure. Literatures have not shown eradication of PJI, to be clearly superior after two- compared to one-stage procedures. Reconstitution of bone defects and the possibility of very high local antibiotic concentration are substantial advantages when using IBG. We recommend a careful one-stage IBG procedure using antibiotic loaded graft for none “difficult to treat” cases

Introduction

Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasties (TKAs). However, if the diaphysis has been previously violated (as in revision of a failed stemmed implant), the resultant sclerotic canal can impair cemented stem fixation, which is vital for cone ingrowth and long-term fixation. We report the outcomes of our novel solution to this problem, in which impaction grafting and a cemented stem in the diaphysis was combined with an uncemented metaphyseal cone for revision TKAs with severely compromised bone.

Introduction

Impaction bone grafting (IBG) is a reliable technique for acetabular revision surgery with large segmental defects. However, bone graft resorption and cup migration are some of the limitations of this tecnique. We assess frequency and outcome of these complications in a large acetabular IBG series.

Femoral revision after cemented total hip arthroplasty (THA) might include technical difficulties, following essential cement removal, which might lead to further loss of bone and consequently inadequate fixation of the subsequent revision stem. Bone loss may occur because of implant loosening or polyethylene wear, and should be addressed at time of revision surgery. Stem revision can be performed with modular cementless reconstruction stems involving the diaphysis for fixation, or alternatively with restoration of the bone stock of the proximal femur with the use of allografts.

Impaction bone grafting (IBG) has been widely used in revision surgery for the acetabulum, and subsequently for the femur in Paprosky defects Type 1 or 2. In combination with a regular length cemented stem, impaction grafting allows for restoration of femoral bone stock through incorporation and remodeling of the proximal femur. Cavitary bone defects affecting the metaphysis and partly the diaphysis leading to a wide femoral canal are ideal indications for this technique. In case of combined segmental-cavitary defects a metal mesh is used to contain the defect which is then filled and impacted with bone grafts. Cancellous allograft bone chips of 2 to 4 mm size are used, and tapered into the canal with rods of increasing diameters. To impact the bone chips into the femoral canal a dummy of the dimensions of the definitive cemented stem is inserted and tapped into the femur to ensure that the chips are firmly impacted. Finally, a standard stem is implanted into the newly created medullary canal using bone cement. To date several studies from Europe have shown favorable results with this technique, with some excellent long-term results reported.

Advantages of IBG include the restoration of the bone stock in the proximal femur, the use of standard length cemented stems and preserving the diaphysis for re-revision. As disadvantages of the technique: longer surgical time, increased blood loss and the necessity of a bone bank can be mentioned.

Uncontained acetabular defects with loss of superior iliac and posterior column support (Paprosky 3) represent a reconstructive challenge as the deficient bone will preclude the use of a conventional hemispherical cup. Such defects can be addressed with large metallic constructs like cages with and without allograft, custom tri-flange cups, and more recently with trabecular metal augments. An underutilised alternative is impaction bone grafting, after creating a contained cavitary defect with a reinforcement mesh. This reconstructive option delivers a large volume of bone while using a small-size socket fixed with acrylic cement.

Between 2005 and 2014, 21 patients with a Paprosky 3B acetabular defect were treated with cancellous, fresh frozen impaction grafting supported by a peripheral reinforcement mesh secured to the pelvis with screws. A cemented all-polyethylene cup was used. Pre-operative diagnosis was aseptic loosening (15 cemented and 6 uncemented). The femoral component was revised in 10 patients. Post-operative course consisted of 3 months of protected weight bearing. Patients were followed clinically and radiographically.

One patient had an incomplete post-operative sciatic palsy. After a mean follow up of 47 months (13 to 128) none of the patients required re-revision of the acetabular component. One asymptomatic patient presented with aseptic loosening 9 years post-operatively. Hardware failure was not observed. All patients had radiographic signs of graft incorporation and bone remodeling. There were no dislocations.

The early and mid-term results of revisions of large acetabular defects with this technique are encouraging. Reconstitution of hip center of rotation and bone stock with the use of a small-size implant makes this technique an attractive option for large defects. Longer follow-up is needed to assess survivability.

Introduction: Revision hip arthroplasty for aseptic loosening of femoral component is successfully treated with impaction bone grafting technique. Owing to easier technique and shorter operative time, distally fixed non-cemented long stems have gained popularity in the present era. However, use of long stems could make subsequent re-revision difficult due to further bone loss. The standard length stem has been often critiqued due to apprehension of peri-prosthetic fracture.

This study aims to determine the long-term outcomes of the impaction bone grafting of the femur for aseptic loosening in revision hip arthroplasty using standard length C-stems. 168 total hip revisions of 162 patients with impaction bone grafting and cemented standard C-stem (done with standardized technique) between 1995 and 2008 at a tertiary referral centre were included. Revisions for infection and segmental bone defects were excluded.

Mean follow-up of the 168 revision hips was 10.5 years (range 5 – 19.1 years). 14 patients (8.3%) were re-revised, reasons being, persistent deep infection (1.8%), repeated dislocations (1.2%), cup loosening (4.8%) and stem loosening (1.2%). Only 1 patient (0.6%) was re-revised due to stem loosening alone. No peri-prosthetic fractures (intra-operative or post-operative) or stem breakage were identified.

Use of standard stem length in hip revisions with impaction bone grafting does not increase the risk of peri-prosthetic fractures, instead, reconstitutes the bone stock. This questions the conventional principle of bypassing the distal cavitation of femur by 2 cortical diameters with the use of long stem. In our experience, a good proximal femur support is key to performance of standard length cemented stems in revision for aseptic loosening irrespective of grade of distal cavitation for cavitatory defects of femur when treated with impaction bone grafting.

The technique involves impaction of cancellous bone into a cavitary femur. If segmental defects are present, the defects can be closed with stainless steel mesh. The technique requires retrograde fill of the femoral cavity with cancellous chips of appropriate size to create a new endomedullary canal. By using a set of trial impactors that are slightly larger than the real implants the cancellous bone is impacted into the tube. Subsequent proximal impaction of bone is performed with square tip or half moon impactors. A key part of the technique is to impact the bone tightly into the tube especially around the calcar to provide optimal stability. Finally a polished tapered stem is cemented using almost liquid cement in order to achieve interdigitation of the implant to the cancellous bone.

The technique as described is rarely performed today in many centers around the world. In the US, the technique lost its interest because of the lengthy operative times, unacceptable rate of peri-operative and post-operative fractures and most importantly, owing to the success of tapered fluted modular stems. In centers such as Exeter where the technique was popularised, it is rarely performed today as well, as the primary cemented stems used there, rarely require revision.

There is ample experience from around the globe, however, with the technique. Much has been learned about the best size and choice of cancellous graft, force of impaction, surface finish of the cemented stem, importance of stem length, and the limitations and complications of the technique. There are also good histology data that demonstrate successful vascularization and incorporation of the impacted cancellous bone chips and host bone.

Our experience at the clinic was excellent with the technique as reported in CORR in 2003 by M Cabanela. The results at mid-term demonstrated minimal subsidence and good graft incorporation. Six of 54 hips, however, had a post-operative distal femoral fracture requiring ORIF. The use of longer cemented stems may decrease the risk of distal fracture and was subsequently reported by the author after reviewing a case series from Exeter.

Today, I perform this technique once or twice per year. It is an option in the younger patient, where bone restoration is desired. Usually in a Paprosky Type IV femur, where a closed tube can be recreated and the proximal bone is reasonable. If the proximal bone is of poor quality, then I prefer to perform a transfemoral osteotomy, and perform an allograft prosthetic composite instead of impaction grafting, and wrap the proximal bone around the structural allograft. I prefer this technique as I can maintain the soft tissues over the bone and avoid the stripping that would be required to reinforce the bone with struts or mesh. Another indication for its use in the primary setting is in the patient with fibrous dysplasia.

Femoral revision in cemented THA might include some technical difficulties, based on loss of bone stock and cement removal, which might lead to further loss of bone stock, inadequate fixation, cortical perforation or consequent fractures. Femoral impaction grafting, in combination with a primary cemented stem, allows for femoral bone restoration due to incorporation and remodelling of the allograft bone by the host skeleton. Historically it has been first performed and described in Exeter in 1987, utilizing a cemented tapered polished stem in combination with morselised fresh frozen bone grafts. The technique was refined by the development of designated instruments, which have been implemented by the Nijmegen group from Holland. Indications might include all femoral revisions with bone stock loss, while the Endo-Clinic experience is mainly based on revision of cemented stems. Cavitary bone defects affecting meta- and diaphysis leading to a wide or so called “drain pipe” femora, are optimal indications for this technique, especially in young patients. Contraindications are mainly: septical revisions, extensive circumferential cortical bone loss and noncompliance of the patient.

Generally, the technique creates a new endosteal surface to host the cemented stem by reconstruction of the cavitary defects with impacted morselised bone graft. This achieves primary stability and restoration of the bone stock. It has been shown, that fresh frozen allograft shows superior mechanical stability than freeze-dried allografts. Incorporation of these grafts has been described in 89%. Technical steps include: removal of failed stem and all cement, reconstruction of segmental bone defects with metal mesh (if necessary), preparation of fresh frozen femoral head allografts with bone mill, optimal bone chip diameter 2–5 mm, larger chips for the calcar area (6–8 mm), insertion of an intramedullary plug including central wire, 2 cm distal the stem tip, introduction of bone chips from proximal to distal, impaction started by distal impactors over central wire, then progressive larger impactors proximal, insertion of a stem “dummy” as proximal impactor and space filler, removal of central wire, retrograde insertion of low viscosity cement (0.5 Gentamycin) with small nozzle syringe, including pressurization, and insertion of standard cemented stem. The cement mantle is of importance, as it acts as the distributor of force between the stem and bone graft and seals the stem. A cement mantle of at least 2 mm has shown favorable results. Post-operative care includes usually touch down weightbearing for 6–8 weeks, followed by 4–6 weeks of gradually increased weightbearing with a total of 12 weeks on crutches.

Relevant complications include mainly femoral fractures due to the hardly impacted allograft bone. Subsidence of tapered polished implants might be related to cold flow within the cement mantle, however, could also be related to micro cement mantle fractures, leading to early failure. Subsidence should be less than 5 mm. Survivorship with a defined endpoint as any femoral revision after 10-year follow up has been reported by the Exeter group being over 90%, while survivorship for revision as aseptic loosening being above 98%. Within the last years various other authors and institutions reported about similar excellent survivorships, above 90%. In addition, a long-term follow up by the Swedish arthroplasty registry in more than 1180 patients reported a cumulative survival rate of 94% after 15 years.

Impaction grafting might technically be more challenging and more time consuming than cement-free distal fixation techniques. It, however, enables a reliable restoration of bone stock which might especially become important in further revision scenarios in younger patients.

Allografts are used to compensate for bone defects resulting from revision surgery, tumor surgery and reconstructive bone surgery. While it is well known that the reduction of fat content of allografts increases mechanical properties, the content of liquids were not assessed with known grain size distribution so far. The aim of the study was to compare the mechanical properties of dried allografts (DA) to allografts mixed with a saline solution (ASS) to allografts mixed with blood (AB) having a similar grain size distribution.

Fresh-frozen morsellized bone chips were cleaned chemically, sieved and reassembled in specific portions with known grain size distribution. A uniaxial compression was used to assess the yield limit of the three groups before and after compaction with a fall hammer apparatus.

No statistically significant difference could be found between all three groups for the yield limit (p=0.339) before compaction. After compaction no statistically significant difference could be found between DA and ASS (p=0.339) and between ASS and AB (p=0.554). AB showed a statistically significant higher yield limit than DA (p=0.022). At the yield limit 3 outliers were removed in DA, 1 in ASS and 1 in AB before compaction and 2 in DA and 1 in AB after compaction.

Excluding the effect of the grain size distribution on the mechanical properties it was shown that allografts have a lower yield limit, when lipids are present. The liquid content of allografts seems to play an inferior role as no statistically significant difference could be found between DA and ASS. It is suggested in accordance with other studies to chemical clean allografts before implantation to reduce the contamination risk and the fat content. An optimum liquid level still remains to be defined. The considerations here described are relevant for filling up bigger bone defects, while in smaller defects the differences between different preparation methods may be less prominent.

Femoral revision in cemented THA might include some technical difficulties, based on loss of bone stock and cement removal, which might lead to further loss of bone stock, inadequate fixation, cortical perforation or consequent fractures. Femoral impaction grafting, in combination with a primary cemented stem, allows for femoral bone restoration due to incorporation and remodeling of the allograft bone by the host skeleton. Historically, it has been first performed and described in Exeter in 1987, utilizing a cemented tapered polished stem in combination with morselised fresh frozen bone grafts. The technique was refined by the development of designated instruments, which have been implemented by the Nijmegen group from Holland.

Indications might include all femoral revisions with bone stock loss, while the ENDO-Klinik experience is mainly based on revision of cemented stems. Cavitary bone defects affecting meta- and diaphysis leading to a wide or so called “drain pipe” femora, are optimal indications for this technique, especially in young patients. Contraindications are mainly: septical revisions, extensive circumferential cortical bone loss and noncompliance of the patient.

Generally the technique creates a new endosteal surface to host the cemented stem by reconstruction of the cavitary defects with impacted morselised bone graft. This achieves primary stability and restoration of the bone stock. It has been shown, that fresh frozen allograft shows superior mechanical stability than freeze-dried allografts. Incorporation of these grafts has been described in 89%.

Technical steps include: removal of failed stem and all cement, reconstruction of segmental bone defects with metal mesh (if necessary), preparation of fresh frozen femoral head allografts with bone mill, optimal bone chip diameter 2 – 5 mm, larger chips for the calcar area (6 – 8 mm), insertion of an intramedullary plug including central wire, 2 cm distal to the stem tip, introduction of bone chips from proximal to distal, impaction started by distal impactors over central wire, then progressively larger impactors proximal, insertion of a stem “dummy” as proximal impactor and space filler, removal of central wire, retrograde insertion of low viscosity cement (0.5 Gentamycin) with small nozzle syringe, including pressurization, insertion of standard cemented stem. The cement mantle is of importance, as it acts as the distributor of force between the stem and bone graft and seals the stem. A cement mantle of at least 2 mm has shown favorable results. Originally the technique is described with a polished stem. We use standard brushed stems with comparable results. Postoperative care includes usually touch down weight bearing for 6–8 weeks, followed by 4–6 weeks of gradually increased weightbearing with a total of 12 weeks on crutches.

Survivorship with a defined endpoint as any femoral revision after 10 year follow up has been reported by the Exeter group being over 90%. While survivorship for revision related to aseptic loosening being above 98%. Within the last years various other authors and institutions reported similar excellent survivorships, above 90%. In addition a long term follow up by the Swedish arthroplasty registry in more than 1180 patients reported a cumulative survival rate of 94% after 15 years.

Impaction grafting might technically be more challenging and more time consuming than cement free distal fixation techniques. It, however, enables a reliable restoration of bone stock which might become important in further revision scenarios in younger patients.

Uncontained acetabular defects with loss of superior iliac and posterior column support (Paprosky 3B) represent a reconstructive challenge as the deficient bone will preclude the use of a conventional hemispherical cup. Such defects can be addressed with large metallic constructs like cages with and without allograft, custom tri-flange cups, and more recently with trabecular metal augments. An underutilised alternative is impaction bone grafting, after creating a contained cavitary defect with a reinforcement mesh. This reconstructive option delivers a large volume of bone while using a small-size socket fixed with acrylic cement.

Between 2006 and 2014, sixteen patients with a Paprosky 3B acetabular defect were treated with cancellous, fresh frozen impaction grafting supported by a peripheral reinforcement mesh secured to the pelvis with screws. A cemented all polyethylene cup was used. Preoperative diagnosis was aseptic loosening (10 cemented and 6 non-cemented). The femoral component was revised in 9 patients. Postoperative course consisted of 3 months of protected weight bearing. Patients were followed clinically and radiographically.

One patient had an incomplete postoperative sciatic palsy. After a mean follow up of 40 months (24 to 104) none of the patients required re-revision. One asymptomatic patient presented with aseptic loosening 9 years postoperatively. Hardware failure was not observed. All patients had radiographic signs of graft incorporation and bone remodeling. There were no dislocations.

The early and mid-term results of revisions for large acetabular defects with this technique are encouraging. Reconstitution of hip center of rotation and bone stock with the use of a small-size implant make this technique an attractive option for these large defects. Longer follow-up is needed to assess survivability.

Impaction grafting is an excellent option for acetabular revision. It is technique specific and very popular in England and the Netherlands and to some degree in other European centers. The long term published results are excellent. It is, however, technique dependent and the best results are for contained cavitary defects. If the defect is segmental and can be contained by a single mesh and impaction grafting, the results are still quite good. If, however, there is a larger segmental defect of greater than 50% of the acetabulum or a pelvic discontinuity, other options should be considered.

Segmental defects of 25–50% can be managed by minor column (shelf) or figure of 7 structural allografts with good long term results. Porous metal augments are now a good option with promising early to mid-term results. Segmental defects of greater than 50% require a structural graft or porous augment usually protected by a cage. If there is an associated pelvic discontinuity then a cup cage is a better solution.

An important question is does impaction grafting facilitate rerevision surgery? There is no evidence to support this but some histological studies of impacted allograft would suggest that it may. On the other hand there are papers that show that structural allografts do restore bone stock for further revision surgery. Also the results of impaction grafting are best in the hands of surgeons comfortable with using cement on the acetabular side, and one of the reasons why this technique is not as popular in North America.

The choice of stem length in total hip revision with impaction bone grafting of femur is essentially based upon the grade of cavitation of femur and surgeon's preference. The standard length stem has been often critiqued for the apprehension of peri-prosthetic fracture. Our study highlights the importance of proximal bone stock rather than distal cavitation in determining the length of femoral stem.

168 total hip revisions of 162 patients with impaction bone grafting and cemented standard C-stem (done with standardized technique) between 1995 and 2008 at a tertiary referral centre were included. Revisions for infection and segmental bone defects were excluded. Serial radiographs were retrospectively analysed by two people independently, using Endoklinik classification, Gruen zones and more and outcomes were analysed.

Mean follow-up of the 168 revision hips was 10.5 years (range 5 – 19.1 years). 14 patients (8.3%) were re-revised, reasons being, persistent deep infection (1.8%), repeated dislocations (1.2%), cup loosening (4.8%) and stem loosening (1.2%). Only 1 patient (0.6%) was re-revised due to stem loosening alone. No peri-prosthetic fractures or stem breakage were identified.

Use of standard stem length in hip revisions with impaction bone grafting doesn't increase the risk of peri-prosthetic fractures even during long term follow up period. This questions the principle of bypassing the distal cavitation of femur by 2 cortical diameters with the use of long stem. In our experience, a good proximal femur support aids in the performance of standard length cemented stems in revision for aseptic loosening irrespective of grade of distal cavitation for cavitory defects of femur treated with impaction bone grafting.

Acetabular reconstruction with impaction bone grafting and a cemented polyethylene aims to reconstitute the bone stock in hip revision. This is an effective but expensive, resource intensive and time consuming technique. Most surgeons remove the articular cartilage from the femoral head allograft. The aim of this study is to reproduce the results using the whole femoral head with the articular cartilage for acetabular impaction grafting.

38 acetabular revisions using impacted morselised bone graft retaining the articular cartilage and a cemented cup were studied retrospectively. The operations were performed by the senior author in Wrightington Hospital, UK with a posterior hip approach. The mean follow up was 4.1 years (range, 1–10 years). Clinical and radiological assessment was made using the Oxford hip score, Hodgkinson's criteria (1988) for socket loosening and the Gie classification (1993) for evaluation of allograft incorporation.

Thirty-six (94.7%) sockets were considered radiologically stable (type 0, 1, 2 demarcations) and two (5.3%) sockets were radiologically loose (type 3 demarcations) but there was no socket migration. Twenty-one (55.3%) cases showed good trabecular remodeling (grade 3). Fourteen (36.8 %) cases showed trabecular remodeling (grade 2). Only three (7.9%) cases showed poor allograft incorporation (grade 1). Mean pre-operative hip score was 41 and post-operative hip score was 21. There was one (2.6%) wound infection treated with oral antibiotics and one (2.6%) periprosthetic femoral fracture treated with cables. Furthermore, there was one (2.6%) case of pulmonary embolism and three (7.89%) cases of asymptomatic heterotopic ossification. One year mortality rate was 2.6% (one case) from heart failure but not associated with the surgery. There have been no socket re-revisions (100% survival) at an average of 4 years.

At a mean follow up of 4 years, results with the aforementioned technique are comparable to other major studies. Compared to the 40% of minimal loss in obtaining pure cancellous graft less than 10% of initial graft mass is lost without removing the articular cartilage. Particularly when the supply of allograft and operative time are limited retaining the articular cartilage of the femoral head is a safe and effective alternative to be considered.

Purpose

The purpose of the present study is to assess 5–10 years' follow-up results after acetabular impaction bone grafting (IBG) in primary cemented total hip arthroplasty (THA) for cases with acetabular bone defect.