The management of femoral bone loss is challenging during revision hip arthroplasty. In patients with Paprosky grade IIIB and IV defects, obtaining fixation and rotational stability using traditional surgical constructs is difficult. The use of a custom-made internal proximal femoral replacement prostheses has been proposed as a solution in patients, with severe femoral bone stock loss. However, there is a paucity in the literature on their use and long-term outcomes. We report on the clinical and radiological results of our cohort. We retrospectively reviewed all patients who underwent internal proximal femoral replacement for revision hip arthroplasty between April 1996 and April 2019. All patients had at least 2 years of follow-up time. 160 patients underwent limb salvage at our institution using internal proximal femoral replacement. The mean follow-up was 79.7 months (S.D 41.3). Indications for revision included periprosthetic fractures, aseptic loosening, and deep infection. The mean Oxford hip score increased from 13.8 (0–22) to 31.5 (18–43) (paired t-test, p < 0.001). Kaplan-Meier prosthesis survival analysis with revision as the endpoint was 87% at 5 years. None required revision of the femoral stem. There were four dislocations (5%) and there was failure to eradicate the deep infection in four. This technique allows instant distal fixation, allowing for early mobilisation. Long-term clinical and radiological outcomes are encouraging and the complication rates are acceptable for this patient group

Aims. Loss or absence of proximal femoral bone in revision total hip arthroplasty (THA) remains a significant challenge. While the main indication for the use of proximal femoral replacements (PFRs) is in the treatment of malignant disease, they have a valuable role in revision THA for loosening, fracture and infection in patients with bone loss. Our aim was to determine the clinical outcomes, implant survivorship, and complications of PFRs used in revision THA for indications other than malignancy. Patients and Methods. A retrospective review of 44 patients who underwent revision THA using a PFR between 2000 and 2013 was undertaken. Their mean age was 79 years (53 to 97); 31 (70%) were women. The bone loss was classified as Paprosky IIIB or IV in all patients. The mean follow-up was six years (2 to 12), at which time 22 patients had died and five were lost to follow-up. Results. The mean Harris Hip Score improved from 42.8 (25.9 to 82.9) pre-operatively to 68.5 (21.0 to 87.7) post-operatively (p = 0.0009). A total of two PFRs had been revised, one for periprosthetic infection eight years post-operatively and one for aseptic loosening six years post-operatively. The Kaplan-Meier survivorship free of any revision or removal of an implant was 86% at five years and 66% years at ten years. A total of 12 patients (27%) had a complication including six with a dislocation. Conclusion. PFRs provide a useful salvage option for patients, particularly the elderly with massive proximal femoral bone loss who require revision THA, with significant clinical improvement. While the survivorship of the implant is good at five years, dislocation continues to be the most common complication. The judicious use of larger femoral heads, dual-mobility constructs, or constrained liners may help to minimise the risk of dislocation. Cite this article: Bone Joint J 2017;99-B:325–9

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur. Cite this article: Bone Joint J 2013;95-B, Supple A:95–7

Aims. Endoprosthetic reconstruction with a distal femoral arthroplasty (DFA) can be used to treat distal femoral bone loss from oncological and non-oncological causes. This study reports the short-term implant survivorship, complications, and risk factors for patients who underwent DFA for non-neoplastic indications. Methods. We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for implant failure was used to calculate implant survivorship. Results. Overall one- and five-year implant survivorship was 87% and 76%, respectively. By indication for DFA, mechanical failure had one- and five-year implant survivorship of 92% and 68%, PJI of 91% and 72%, and distal femur fracture/nonunion of 78% and 70% (p = 0.618). A total of 37 patients (49%) experienced complications and 27 patients (36%) required one or more reoperation. PJI (n = 16, 21%), aseptic loosening (n = 9, 12%), and wound complications (n = 8, 11%) were the most common complications. Component revision (n = 10, 13.3%) and single-stage exchange for PJI (n = 9, 12.0 %) were the most common reoperations. Only younger age was significantly associated with increased complications (mean 67 years (SD 9.1)) with complication vs 71 years (SD 9.9) without complication; p = 0.048). Conclusion. DFA is a viable option for distal femoral bone loss from a range of non-oncological causes, demonstrating acceptable short-term survivorship but with high overall complication rates. Cite this article: Bone Jt Open 2022;3(3):173–181

Introduction. Modular tapered implants have been suggested as the optimal treatment in patients with severe femoral bone loss undergoing revision total hip arthroplasty (THA). The purpose of this study is to describe minimum 2 year follow up of patients treated with modular tapered prostheses for Paprosky type IIIB and IV femoral bone loss in revision THA. Methods. 44 Consecutive patients with Paprosky type IIIB (23) or IV (21) femurs undergoing revision total hip arthroplasty to cementless modular tapered prostheses were studied. Harris Hip Scores were obtained prior to revision on all patients except those presenting with acute implant failure or periprosthetic fracture. 10 Patients were deceased within 2 years of surgery; the remaining 18 were followed for an average of 42 months (range 25-69 months). Clinical outcomes were measured using the Harris Hip Score, and radiographs were assessed for signs of stem loosening or subsidence >4mm. Results. No further revisions were required in patients who were deceased within 2 years. In those with >2 year follow up, there were 4 additional revisions: 1 for infection, 2 for instability, and 1 for periprosthetic fracture. In patients with surviving implants, the mean Harris Hip Score improved from 33 (range 11-49) pre-operatively to 77 (range 55-100), and there was no radiographic evidence of loosening or subsidence at time of final follow up. Conclusions. These outcomes support the use of modular tapered implants as a safe and effective option for revision arthroplasty of type IIIB and IV femurs

Aims. There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. Methods. We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality. Results. The cumulative incidence of septic failure was 8% (95% confidence interval (CI) 3.5 to 15) at one year, 13.8% (95% CI 7.6 to 22) at two years, and 19.7% (95% CI 12 to 28.6) at five and ten years of follow-up. A femoral bone defect worse than Paprosky IIIA (hazard ratio (HR) 13.58 (95% CI 4.86 to 37.93); p < 0.001) and obesity (BMI ≥ 30 kg/m. 2. ; HR 3.88 (95% CI 1.49 to 10.09); p = 0.005) were significantly associated with septic failure. Instability and periprosthetic fracture were the most common reasons for mechanical failure (5.7% and 4.5%, respectively). The cumulative incidence of aseptic failure was 2% (95% CI 0.4 to 7) at two years, 9% (95% CI 4 to 17) at five years, and 12% (95% CI 5 to 22) at ten years. A previous revision to treat PJI was significantly associated with non-septic failure (HR 9.93 (95% CI 1.77 to 55.46); p = 0.009). At the five-year timepoint, 93% of the patients were alive (95% CI 84% to 96%), which fell to 86% (95% CI 75% to 92%) at ten-year follow-up. Conclusion. Massive femoral bone loss was associated with greater chances of developing a further septic failure. All septic failures occurred within the first five years following the one-stage exchange. Surgeons should be aware of instability and periprosthetic fracture being potential causes of further aseptic revision surgery. Cite this article: Bone Joint J 2021;103-B(7):1247–1253

We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D’Aubigné and Postel score was 5.5 points (1 to 8). The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36 to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts. This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss

We performed a retrospective analysis of the clinical and radiological outcomes of total hip replacement using an uncemented femoral component proximally coated with hydroxyapatite. Of 136 patients, 118 who had undergone 124 primary total hip replacements were available for study. Their mean age was 66.5 years (19 to 90) and the mean follow-up was 5.6 years (4.25 to 7.25). At the final follow-up the mean Harris hip score was 92 (47.7 to 100). Periprosthetic femoral fractures, which occurred in seven patients (5.6%), were treated by osteosynthesis in six and conservatively in one. We had to revise five femoral components, one because of aseptic loosening, one because of septic loosening and three because of periprosthetic fracture. At the final follow-up there were definite signs of aseptic loosening in two patients. Radiologically, proximal femoral bone loss in Gruen zones I and VI was evident in 96.8% of hips, while bone hypertrophy in zones III and V was seen in 64.7%. In 24 hips (20.2%) the mean subsidence of the stem was 3.7 mm which occurred within the first 12 postoperative weeks. This indicated poor initial stability, which might have been aggravated by early weight-bearing. The high rate of failure in our study suggests that proximal femoral bone loss affects the long-term survival of the replacement

Background. Revision THA presents significant challenges for the surgeon when the proximal femur is deficient or mechanically unreliable. The aim of this study is to assess the clinical and functional results of the use of tumor enndoprosthesis to reconstruct the proximal femur when there is massive bone loss. Patients and Methods. A prospective study was conducted involving 10 cases. The follow up of the cases ranged from 12 months to 30 months with a mean period of an average of 23months. The indications for revision surgery were aseptic loosening in 9 cases and septic loosening in one case Harris hip score was used for pre and postoperative clinical evaluation of the patients. Results. At the latest follow up the Harris Hip scores improved from a preoperative average of 16 (range, 3-47), to a postoperative average of 75.6 (range, 66-94). The complications that we encountered in the study included one case of superficial wound infection, another case developed sciatic nerve palsy postoperatively. No other complications were reported. Conclusion. Revision hip replacement in proximally compromised femurs presents a significant surgical challenge. When there is massive proximal femoral bone loss proximal fitting revision stems do not achieve adequate fixation hence the use of tumor prosthesis is indicated

The treatment of substantial proximal femoral bone loss in young patients with developmental dysplasia of the hip (DDH) is challenging. We retrospectively analysed the outcome of 28 patients (30 hips) with DDH who underwent revision total hip replacement (THR) in the presence of a deficient proximal femur, which was reconstructed with an allograft prosthetic composite. The mean follow-up was 15 years (8.5 to 25.5). The mean number of previous THRs was three (1 to 8). The mean age at primary THR and at the index reconstruction was 41 years (18 to 61) and 58.1 years (32 to 72), respectively. The indication for revision included mechanical loosening in 24 hips, infection in three and peri-prosthetic fracture in three. Six patients required removal and replacement of the allograft prosthetic composite, five for mechanical loosening and one for infection. The survivorship at ten, 15 and 20 years was 93% (95% confidence interval (CI) 91 to 100), 75.5% (95% CI 60 to 95) and 75.5% (95% CI 60 to 95), respectively, with 25, eight, and four patients at risk, respectively. Additionally, two junctional nonunions between the allograft and host femur required bone grafting and plating. An allograft prosthetic composite affords a good long-term outcome in the management of proximal femoral bone loss in revision THR in patients with DDH, while preserving distal host bone

Introduction and Aims: This study evaluates the effect of risedronate (Actonel) on proximal femoral bone loss after total hip arthroplasty (THA). Studies have shown that alendronate (Fosamax) reduces periprosthetic bone loss after primary THA. We hypothesise that patients who take risedronate, post-THA, will have less bone loss than patients not taking risedronate. Method: All patients in this prospective study undergo uncemented THA and follow the same post-operative protocol. Patients in the study group take five mg of risedronate daily, beginning five to seven days pre-operatively, and continuing for 24 months after surgery. Patients randomised to the control group do not receive risedronate. Dual energy x-ray absorptiometry (DEXA) scans of the operated proximal femur are performed on all patients pre-operatively, three to seven days post-operatively, and then six weeks, six months, one year and two years post-operatively. Longitudinal changes in bone mineral density (BMD) are compared within and between the two groups. Results: Analysis of data for female subjects showed the percent change in BMD (g/cm. 2. ) for the control group at six months was −9.71% and for the study group −4.55%. Longitudinal changes in BMD between groups were examined using repeated measures analysis within each gender and were found to be significantly different between groups of females (p=.05). A similar trend was observed among the male subjects. One and two-year prospective data will be presented at the meeting. Conclusion: Bone loss after THA can increase the rate of failure of THA and cause revision surgery to be more complex and have compromised outcomes. Short-term data reveal significantly decreased bone loss after uncemented THA among patients taking risedronate

Aseptic loosening and osteolysis may cause significant periprosthetic femoral bone destruction, often necessitating bypass of the deficient proximal femur to obtain stable fixation in the distal diaphysis. The purpose of the present study was to report our results of femoral component revision using a distally locked revision femoral stem for the treatment of the severe proximal femoral bone loss. We evaluated 21 hips in 20 patients who underwent revision hip arthroplasty associated with Paprosky grade-IIIB or IV femoral deficiencies. Three hips were associated with a Vancouver type-B3 periprosthetic femoral fracture. The mean age at the time of revision was 70.8 (51–82) years old with 5 men and 15 women. The mean duration of follow-up was 5.1 years. The femoral implant used for the revision was the Cannulok Revision Prosthesis in 16 hips and the Huckstep interlocking stem in five. Gaps between the stem and the host bone were filled and impacted with bone chips and morselized bone prior to stem insertion. One femoral implants were resected because of deep infection Subsidence was absent and stable fixation was achieved in all patients. Non-progressive radiolucent lines in zones 1 and 7 according to Gruen’s classification were detected in five cases. Cortical hypertrophy around the interlocking screws were seen in ten cases. No disadvantages or complications of the interlocking screws were observed. All the fractures have united within three to five months. Intraoperative fractures in the diaphyseal area occurred in five hips in which trochanteric osteotomy was used. A diaphyseal fixation of the femoral stem with distal interlocking screws appears to provide primary axial and rotational stability of the prosthesis and early mobilization. This implant may provide a satisfactory alternative for the management of revision hip surgery in the presence of a loose femoral component with massive bone loss. Longer-term follow-up data from this study will be needed to confirm these outcomes

Aseptic loosening and osteolysis may cause significant periprosthetic femoral bone destruction, often necessitating bypass of the deficient proximal femur to obtain stable fixation in the distal diaphysis. The purpose of the present study was to report our results of femoral component revision using a distally locked revision femoral stem for the treatment of the severe proximal femoral bone loss. We evaluated 21 hips in 20 patients who underwent revision hip arthroplasty associated with Paprosky grade-IIIB or IV femoral deficiencies. Three hips were associated with a Vancouver type-B3 periprosthetic femoral fracture. The mean age at the time of revision was 70.8 (51–82) years old with 5 men and 15 women. The mean duration of follow-up was 5.1 years. The femoral implant used for the revision was the Cannulok Revision Prosthesis in 16 hips and the Huckstep interlocking stem in five. Gaps between the stem and the host bone were filled and impacted with bone chips and morselized bone prior to stem insertion. One femoral implants were resected because of deep infection Subsidence was absent and stable fixation was achieved in all patients. Non-progressive radiolucent lines in zones 1 and 7 according to Gruen’s classification were detected in five cases. Cortical hypertrophy around the interlocking screws were seen in ten cases. No disadvantages or complications of the interlocking screws were observed. All the fractures have united within three to five months. Intraoperative fractures in the diaphyseal area occurred in five hips in which trochanteric osteotomy was used. A diaphyseal fixation of the femoral stem with distal interlocking screws appears to provide primary axial and rotational stability of the prosthesis and early mobilization. This implant may provide a satisfactory alternative for the management of revision hip surgery in the presence of a loose femoral component with massive bone loss. Longer-term follow-up data from this study will be needed to confirm these outcomes

In osteoporosis treatment, current interventions, including pharmaceutical treatments and exercise protocols, suffer from challenges of guaranteed efficacy for patients and poor patient compliance. Moreover, bone loss continues to be a complicating factor for conditions such as spinal cord injury, prescribed bed-rest, and space flight. A low-cost treatment modality could improve patient compliance. Electrical stimulation has been shown to improve bone mass in animal models of disuse, but there have been no studies of the effects of electrical stimulation on bone in the context of bone loss under hormone deficiency such as in post-menopausal osteoporosis. The purpose of this study was to explore the effects of electrical stimulation on changes in bone mass in the ovariectomized rat model of post-menopausal osteoporosis.

All animal protocols were approved by the institutional Animal Research Ethics Board. We developed a custom electrical stimulation device capable of delivering a constant current, 15 Hz sinusoidal signal. We used 30 female Sprague Dawley rats (12–13 weeks old). Half (n=15) were ovariectomized (OVX), and half (n=15) underwent sham OVX surgery (SHAM). Three of each OVX and SHAM animals were sacrificed at baseline. The remaining 24 rats were separated into four equal groups (n=6 per group): OVX electrical stimulation (OVX-stim), OVX no stimulation (OVX-no stim), SHAM electrical stimulation (SHAM-stim), and SHAM no stimulation (SHAM-no stim). While anaesthetized, stimulation groups received transdermal electrical stimulation to the right knee through bilateral skin-mounted electrodes (10 × 10 mm) with electrode gel. The left knee served as a non-stimulated contralateral control. The no-stimulation groups had electrodes placed on the right knee, but not connected. Rats underwent the stim/no-stim procedure for one hour per day for six weeks. Rats were sacrificed (CO2) after six weeks. Femurs and tibias were scanned by microCT focussed on the proximal tibia and distal femur. MicroCT data were analyzed for trabecular bone measures of bone volume fraction (BV/TV), thickness (Tb.Th), and anisotropy, and cortical bone cross-sectional area and second moment of area.

Femurs and tibias from OVX rats had significantly less trabecular bone than SHAM (femur BV/TV = −74.1%, tibia BV/TV = −77.6%). In the distal femur of OVX-stim rats, BV/TV was significantly greater in the stimulated right (11.4%, p < 0 .05) than the non-stimulated contralateral (left). BV/TV in the OVX-stim right femur also tended to be greater than that in the OVX-no-stim right femur, but the difference was not significant (17.7%, p=0.22). There were no differences between stim and no-stim groups for tibial trabecular measures, or cortical bone measures in either the femur or the tibia.

This study presents novel findings that electrical stimulation can partially mitigate bone loss in the OVX rat femur, a model of human post-menopausal bone loss. Further work is needed to explore why there was a differential response of the tibial and femoral bone, and to better understand how bone cells respond to electrical stimulation. The long-term goal of this work is to determine if electrical stimulation could be used as a complementary modality for preventing post-menopausal bone loss.

1. A motor-cyclist's temporary loss of ten inches (25 centimetres) of femoral shaft and its replacement are recorded.

2. The mechanism of injury is considered.

3. The management of extensive bone loss is discussed.

4. Attention is drawn to the importance of retained periosteum and its contribution to healing in such injuries.

Introduction: Cementless revision hip arthroplasties require a stable initial fixation that does not compromise a subsequent bone reconstruction. In case of severe femoral bone loss, stems usually requires distal fixation that may induce stress shielding and finally reduce the spontaneous bone reconstruction. We introduced the use of distally locked revision stems in 1993 hoping strong fixation and bone reconstruction. The goal of the current study was to assess if these components fulfill these two objectives. Materials and Methods: 101 cementless femoral revision stems with distal locking by screws (Ultime™ Wright-Cremascoli) were inserted from 1993 to 2001. These stems were smooth distally and porous coated with or without HA 1/3 proximally. The indication to use these components was severe bone loss (Paprosky grade IIC and III in 51%) when press fit distal fixation could not be obtained. The use of bone graft was limited to segmental defects or to treat trochanteric non-union. An extended trochanteric osteotomy was performed in 89%. The revision was performed because of aseptic loosening in 43,4%, periprosthetic fracture in 24,2% and infected loosening in 25,2%. The results were assessed after a mean follow-up of 6 years (5–12). Results: 13 patients deceased and 2 were lost for follow-up. All the extended trochanteric osteotomies healed. Merle d’Aubigné hip score increased from 8.3 to 13.4, but thigh pain was observed in 44%. Bone reconstruction was significant according to Hoffman index at 3 levels of assessment. The 5-year survivorship was 87% considering aseptic revision for any reason. Seventeen repeated femoral procedures were performed: 9 related to thigh pain (because there was no proximal osteointegration) that were revised for short primary stems, 8 because of stem fractures (all occurred at the level of the proximal hole with the same stem size because there was no proximal fixation as long as the stems were smooth or without HA-coating. Discussion: This serie has the longest follow-up using locked revision stems. Despite severe pre-operative bone loss, primary fixation and significant bone reconstruction were obtained for all the cases without extensive bone grafting. The major weakness, thigh pain and stem break, were related to unadequate femoral coating for these cementless stems that did not achieved osteointegration. Conversly, the reoperations were simple, allowing the use of short primary designs as bone reconstruction was achieved in all cases without extensive bone grafting. These locked stems allow a strong primary distal fixation that does not compromise bone regeneration. An improvement of femoral coating (extension to 2/3 and use of hydroxyapatite) may reduce the rate of thigh pain and reoperation

Revision total hip arthroplasty (THA) is challenging when there is severe loss of bone in the proximal femur. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with severe proximal femoral bone loss treated with a fluted, tapered, modular femoral component. Between January 1998 and December 2004, 92 revision THAs were performed in 92 patients using a single fluted, tapered, modular femoral stem design. Pre-operative diagnoses included aseptic loosening, infection and peri-prosthetic fracture. Bone loss was categorised pre-operatively as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic fracture. The mean clinical follow-up was 6.4 years (2 to 12). A total of 47 patients had peri-operative complications, 27 of whom required further surgery. However, most of these further operations involved retention of a well-fixed femoral stem, and 88/92 femoral components (97%) remained in situ. Of the four components requiring revision, three were revised for infection and were well fixed at the time of revision; only one (1%) was revised for aseptic loosening. The most common complications were post-operative instability (17 hips, 19%) and intra-operative femoral fracture during insertion of the stem (11 hips, 12%). Diaphyseal stress shielding was noted in 20 hips (22%). There were no fractures of the femoral component. At the final follow-up 78% of patients had minimal or no pain.

Revision THA in patients with extensive proximal femoral bone loss using the Link MP fluted, tapered, modular stem led to a high rate of osseointegration of the stem at mid-term follow-up.

Cite this article: Bone Joint J 2015; 97-B:312–17.

Revision of a failed femoral component in the face of extensive bone loss is a major challenge. When the bone loss extends down below the isthmus it may be difficult to obtain longitudinal stability with a tapered or fully porous coated prosthesis. If subsidence occurs then recurrent dislocation can be an insoluble problem. This study reviews the use of a distally interlocked femoral component designed to address this challenging situation.

We have reviewed 21 cases in which extensive bone loss made the use of an interlocking prosthesis desirable. The average time from surgery was over four years. All patients completed an Oxford hip score and an EO-50. All radiographs were reviewed.

There were 14 males and seven females with an overall average age of 74 years at the time of surgery. Patients had had an average of two previous THR’s, and up to nine previous hip operations. One patient underwent re-revision because of subsidence related to screw cut out. There was one dislocation. Patient satisfaction was high with low Oxford hip scores compared with other revision prostheses, and good EO – 50 ratings.

This type of prosthesis offers a very satisfactory solution to difficult revision situations when bone loss makes the use of regular prostheses difficult. The prosthesis used in this study has a low offset and thus dislocation precautions should be emphasised.

Introduction: An increasing number of patients present for revision hip replacement with severe bone loss. The results of cemented revision in these cases are poor. This study was conducted to determine the medium term clinical and radiological outcome of 50 consecutive revision hip replacements performed using custom femoral stems.

Materials and Method: 50 consecutive hips (49 patients) performed by the senior author between 1992 and 1995 were identified. The indications for revision were aseptic loosening in 42 cases, infection in 7 cases (6 of which were revised using a two-stage technique), and dislocation in one case. The stems are manufactured on the basis of standardised measurement films using specially developed software. The design includes proximal macrogrooves with hydroxyapatite coating, an anterior flare, a lateral flare and a collar. The average follow up was 88.4 months (range 12–111 months). All patients were evaluated radiologically and using Harris, Oxford and WOMAC hip scores.

Results: The patients were assessed by an independent observer. All had severe bone loss according to AAOS and Paprosky classifications. 5 patients died due to causes unrelated to their hip replacement, 5 were lost to follow up or did not respond to questionnaires sent. The remaining patients had average preoperative scores of HHS 40.8 (range 8–87), Oxford 43.5 (range18–56) and WOMAC 82.5 (range 40–120) and had improved to HHS 74.4 (range 19–99), Oxford 25.5(range 12–51) and WOMAC 43.8 (range 13–89).

Conclusions: The use of customised revision stems allows the implant to be tailored to the patient’s bone stock and femoral anatomy. This technique avoids the massive inventory of implants and trials needed for highly modular revision systems, but nevertheless leads to excellent bone implant apposition and interface stability. The clinical results are excellent at medium term review, and the survivorship compares very favourably with other revision series.