Substantial bone loss and bone defects are the most challenging problems faced by the surgeon performing revision surgery. Of the many techniques available, impaction bone grafting aims to achieve stability of an implant with the use of compacted, morselized bone graft and subsequently allows restoration of bone stock by bone ingrowth. This technique was proposed with a highly polished double tapered stem. This technique has also been subsequently used with stems of varying surface finish and shape. We report here our experience with impaction grafting using Charnley stem and variants with 8–10 year results assessing the radiological appearance and subsequent behaviour of the impacted allograft.

A prospective radiological study of revision hip arthroplasty done for aseptic loosening with femoral bone loss is presented. Pre operative bone loss was assessed using the Endo Klinik grading system. Impaction grafting with fresh frozen femoral head allograft and the flanged 40 size Charnley stem was used in 17 cases and extra heavey flanged 40 size was used in 9 casaes. Post operative and annual review radiographs were examined for graft distribution, graft consolidation, cortical repair and subsidence of the stem.

Twenty six revisions performed in 25 patients between May 1994 and November 1996 were followed up for 8–10 years. Mean age was 66 years(range 26–83 years). There were eighteen male and 7 female patients. One patient died 2 years and 9 months after the operation. Pre operatively Endo Klinik grade 2 bone loss was seen in 7 cases and grade 3 bone loss was seen in 19 cases. Post operative radiographs showed even graft distribution in twenty cases, five patients had poor filling in Gruen zone 3 and one patient had poor filling in zone 2. All cases demonstrated evidence of graft consolidation by one year. Twenty two cases showed no further changes after 8–10 years. Two cases of subsidence have been revised and one patient is awaiting revision ( 8 years after revision). Two of these were extra heavy flanged 40 stems. Three cases showed subsidence > 5mm and were associated with graft deficiency in zone 2 or 3. Out of these three one had an extra heavy flanged 40 stem inserted. There were no medical complications or deep infection following surgery in these patients. One patient had dislocation.

In conclusion, femoral revision using impaction grafting with the Charnley stem produces satisfactory radiological results in the medium to long term. Good graft distribution on a postoperative radiograph is associated with graft consolidation, cortical repair and minimal stem subsidence. Extra heavy flanged 40 stems perform less satisfactorily compared to the flanged 40 stems. Inadequate graft filling is associated with stem subsidence and revision. These findings highlight the importance of meticulous surgical technique to ensure even graft distribution. This study supports the taper of the Charnley stem and suggests that a vaquasheen finish is not contraindicated.

Low Contact Stress(LCS) total knee arthroplasty was developed to reduce contact stress on the bearing surface and to minimise stresses at the interface between the host bone and the implant surface leading to long term implant survival. The rotating platform was introduced as the bearing interface when both cruciates are sacrificed. It has a central cone which engages into a matching cone in the tibial tray. This allows unconstrained axial rotation of the bearing surface. However, this potentially leaves the platform susceptible to subluxation/dislocation. The reported rate of this complication varies from 0.5% to 4.65%.

In this study from a single center we report the incidence and highlight the associated causative factors found in our series. There were 1053 Low Contact Stress total knee arthroplasties performed between 1994 and 2003. We reviewed 10 knees in 9 patients who had dislocation of the polyethylene rotating platform. This amounts to 0.95% in our series. All the patients with dislocation were women. Average age was 72 years(range 62–84). Osteoarthritis was the primary diagnosis in 8 patients. One patient was suffering from rheumatoid arthritis was on long term steroid therapy and had bilateral dislocations. One patient with Osteoarthritis with Parkinson’s disease went onto have 2 recurrent dislocations. Pre-operative deformity was varus in 9 knees(range 4–10 degrees) and valgus of 15 degrees was noted in one. Time from index operation to dislocation ranged from as early as 10 days to 10 months. There was history of trauma and acute presentation only in one patient. In one patient the knee dislocated while she twisted her knee in bed and in another while climbing up the stairs. In the remaining seven patients the presentation was subacute with symptoms such as pain, decreased range of motion, swelling and a clunking sensation while walking.

Although manipulation under anaesthesia was successful in 3 patients, all of them had recurrent dislocations and two patients had revision to a deepdish platform. Failed closed reduction led to open reduction in two patients with replacement of the rotating platform to deepdish (12.5 mm) type in one. Following both procedures knee was immobilised in a cast for 6 weeks. Five patients were directly revised without attempting closed reduction to a deepdish rotating platform. At revision in all cases the platform was found to be rotated medialy and posteriorly. Soft tissue imbalance and laxity were seen in all but one. At an average followup of 48.5 months (range 11–84 months) no patient had recurrent instability.

Increasing age, questionable soft tissue integrity and varus deformity were significantly associated with rotating platform dislocation. Closed reduction may be possible but invariably leads to recurrence of dislocation and open reduction with revision of the rotating platform gives reliable results. Replacing the rotating platform with a thicker deepdish bearing provides satisfactory stability at revision surgery. Meticulous surgical technique with accurate soft tissue balancing are important in reducing the incidence of dislocations.

Femoral revision total hip arthroplasty is a technically demanding procedure, especially when there is extensive proximal femoral bone loss. Secure fixation maynot be possible to achieve if the implant relies solely on proximal metaphyseal fit. The use of a long tapered cementless stem having a microporous surface offers a strong anchorage distal to the damaged bony segment. By bypassing the compramised proximal femur, initial implant stability is achieved and a high rate of osseointegration can be expected.

We present our experience with Link MP reconstruction stem which utilises distal fixation and has a modular proximal end.. The prosthesis is made of Tilastan( Ti6AI4V Eli Titanium Alloy) with microporous texture of about 70 microns pore diameter. The distally tapered stem is angled about 3 degrees proximally to enable easy insertion of the stem. In our series there were 53 stem revisions done in 51 patients. Twenty three were males and 28 were female patients. The average age of the male patient was 66 years and that of the female was 74 years. The mean followup was 37 months( range 12–76 months.) Indications for revision were aseptic loosening in 35 cases, infected hip replacements in 8 patients and periprosthetic fracture in ten cases. Revision for infected primary arthroplasty was done in two stages with the Link MP stem inserted at the second stage.

All the proximal femoral defects were classified radiographically as described by Gustillo and Pasternak. There were 29 type 2 defects and 14 type 3 defects. The periprosthetic fractures were classified as per the Vancouver system and all the cases were type b fractures. Clinical scoring as described by d’Aubigne and Postel was used . The mean preoperative score was 3.5 while average score at the time of follow-up was 9.8. The subsidence ranged from none to 6mm. Good radiological evidence of proximal femoral restoration was seen in 44% of the cases in our series. Complications included greater trochanter fracture in 4 cases, perforation of the anterior cortex during reaming using the rasp in 2 cases and dislocation in one patient. In one case there was unacceptable penetration of the implant medially and this was subsequently treated by re-revision with a Huckstep stem. There were two intraoperative fractures which were treated with circlage wire fixation and they went on to union. None of the patients required a re-revision till date.

In conclusion , our experience with Link MP reconstruction stem has been encouraging as shown by the improved d’Aubigne & Postel scores and low rate of complications. We also observed proximal femoral restoration and high implant survivorship in our series.