Purpose

To determine if minimally invasive surgery (MIS) for primary hip replacement surgery increases the risk of long term aseptic loosening as predicted by implant micromotion measured with radiostereometric analysis (RSA).

Purpose

Aseptic loosening of the tibial component of total knee prosthesis is a common cause of revision surgery. While micromotion at the bone-implant interface can now be accurately measured with Radiostereometric Analysis (RSA), mechanisms responsible for loosening remain poorly understood. The purpose of this study was to investigate the association between bone density in the proximal tibia and post-operative knee implant migration.

Purpose

The foam metal backed Advance BioFoam Knee Arthroplasty components utilize a porous titanium coating on the underside of the tibial baseplate, intended to promote bone in-growth and provide a more robust bone-implant interface without cement. There is also a version of the Biofoam Advance that incorporates screwed fixation that allows for augmented fixation with up to four titanium screws; however, it is not clear that this augmentation is necessary. The purpose of this study was to employ radiostereometric analysis (RSA) to compare implant migration in a randomized controlled trial of this implant design with or without screw fixation.

Purpose: To determine if MIS for primary hip replacement surgery increases the risk of long term aseptic loosening as predicted by implant micromotion measured with radiostereometric analysis (RSA).

Method: Ninety patients undergoing primary THA for osteoarthritis (exclusion criteria: post-traumatic arthritis, rheumatoid arthritis, hip dysplasia, previous hip infection) were randomized to undergo THR surgery utilizing the standard direct lateral approach (n=45; 24 male; age=58 yrs; BMI=27) or MIS via a one-incision direct lateral approach using specific instrumentation (n=45; 23 male; age=55; BMI=29). Uncemented acetabular and femoral (ProfemurZ) components were used with ceramic on ceramic bearings. The femur was marked with 9 tantalum beads placed in the greater trochanter, lesser trochanter, and femoral shaft distal to the tip of the prosthesis. Post-operative care was be standardized according to the care maps at our institution. Primary outcome measure was femoral stem MTPM (maximum total point motion) measured using Model-based RSA. Stereo supine X-rays were taken before weight bearing and 3, 6, and 12 months postoperatively. At the same time intervals Harris Hip Score, Oxford-12, WOMAC, and SF36 questionnaires were administered. Rates of infection, dislocation and revision were recorded.

Results: Eleven patients were lost to follow-up (4 due to missing post-op exams; 5 did not have enough beads placed during surgery; 2 were revised due to failure of the ceramic femoral head). There were five long neck fractures at 17–30 months postop that are reported in detail in a related abstract. There were no differences between groups for all outcome measures. Mean MTPM at 12 months was 2.5mm (SD=1.8mm) for the MIS group and 2.6mm (SD=1.2mm) for the standard group.

Conclusion: No difference between groups at one year indicates MIS for uncemented primary THR through a direct lateral approach does not appear to negatively affect stability of the femoral stem. Although promising, these results require confirmation with 2-year RSA data.

Purpose: To report a series of unexpected femoral neck failures in a series total hip replacement surgeries using a modular femoral component.

Method: A series of 443 hip replacement patients received modular necks as part of a non cemented hip replacement with ceramic articulations at the acetabulum and femoral head interface. The first implant of the device was on June 8, 2004 and the last on June 12, 2009. Ninety-one of those patients were enrolled in a RSA study of component stability within the proximal femur.

Results: The index fracture of a femoral neck occurred on March 8, 2009 when the patient (28 months post hip replacement) reported a fall. Subsequently five patients have had a fracture of the modular neck. There were five fractures within the RSA study group and one within the non study group (all occurred 17 months to 30 months post op). All fractures were long necks (10.5 mm). There was no difference in femoral component micromotion as measured with RSA between the fractured group and the unrevised group.

Conclusion: Initial non-destructive testing of one retrieval revealed fatigue failure of the femoral neck. An independent study of all relevant data was implemented which included destructive testing of the implants and clinical data with respect to patient activity. We report the outcome of all those investigations.

Purpose: To meet the increasing demand for arthroplasty in Canada healthcare providers are investigating efficiency improvements to maximize utilization of limited surgical resources. One target is routine annual arthroplasty follow-up for which there are no established guidelines. A previous study by the authors revealed that 52% of arthroplasty patients could be followed with standardized questionnaires and x-rays resulting in a 30% savings to the healthcare system. In this study we report the patient time, travel and financial burdens for annual follow-up at a tertiary care centre versus a hypothetical model using standardized assessment at community hospitals and a web-enabled PACS.

Method: A consecutive sample survey of elective THA and TKA patients (n=158; 99 females; 94 THA; 64 TKA; mean age=69 years) who were at least twelve months postoperative. Patient’s address, work status, mode of travel and times required for travel, physician consult, x-ray, and clinic wait were recorded. A web-based mapping application was used to determine distances from patients’ homes to the tertiary care centre and nearest community hospital. Financial burden was calculated using Statistics Canada figures for average Canadian wage and private vehicle travel costs.

Results: Sixteen patients were working at the time of the study and 149 travelled in a private vehicle. For the tertiary care centre: round-trip distance was 168 km, total time burden was 194 minutes (travel=129 minutes, clinic wait=54 minutes, time with physician=6 minutes, x-ray=5 minutes), and total financial burden per patient was $58. For the community hospital: round-trip distance was 19 km, total time burden was 39 minutes (travel=14 minutes, clinic wait=20 minutes, x-ray=5 minutes), and total financial burden was $7.

Conclusion: Utilizing community hospital resources for arthroplasty follow-up could reduce patients’ travel by 89%, financial burden by 88%, and time burden by 81%. This approach has the potential to enable the focusing of arthroplasty clinic follow-up resources only on patients reporting problems or with symptomatic x-rays thus freeing up surgeon time for surgeries. There are also the broader societal implications of reducing ‘health miles’ and the resulting carbon dioxide emissions related to health care delivery by leveraging new technologies to move information rather than people.

Purpose: Porous metal technology may have significant impacts on implant fixation and long-term survival due to their high co-efficient of friction and similarity to trabecular bone in morphology and mechanical behaviour. While promising, the in vivo mechanical behaviour and micromotion at the interface has not previously been reported on. We report on the 2-year results of an RCT using radiosterometric analysis (RSA) to asses a porous metal (PM) monoblock tibial component.

Method: Patients undergoing TKA were randomized to receive a either the PM (n=34) or the cemented tibial component (n=33). A standardized protocol was used for intra and post-operative factors. RSA exams were obtained postoperatively within 4 days of surgery and at 6, 12 and 24 months. One patient was excluded due to an intraoperative complication, and four others were lost to follow-up due to poor bead visibility or morbidity. Standard subjective outcome measures were applied.

Results: There were no revisions in either group. The PM group exhibited two distinct migration patterns. One group stabilized immediately with similar migration to the cemented cases (0.38 vs. 0.46 p=0.4). A subset of 6 PM cases demonstrated significantly higher initial migration (mean=2.01mm, p< 0.01) but appeared stable at 2 years. In addition, 3 of the 6 high migration cases manifested independent bead subsidence. This was determined to be due to PM plate deformation. Two cemented cases were considered at risk for early failure due to aseptic loosening because of RSA migration pattern. There were no differences between groups in the subjective health outcome measures.

Conclusion: A subset of PM components demonstrated high early migration followed by stabilization. It appears that some of these PM components deformed under load, most often in the posteromedial corner, perhaps as a result of malalignment or ligament imbalance. The implications of this finding are yet to be determined.

Tumour cells induce osteolysis by producing multiple cytokines that indirectly activate osteoclasts; this process is dependent upon surface expression of a protein known as “receptor activator of nuclear factor kB ligand (RANK-L)” on osteoblasts (OB), and subsequent osteoclast (OC) interaction via surface expressed RANK. Harnessing this RANK-RANK-L interaction has potential for reducing cancer osteolysis. The aim of this study is to prevent tumour-induced osteolysis by ablating osteoclast activation.

A monocyte cell line (RAW 264.7) was grown in vitro in the presence of RANK-L and recombinant mouse macrophage colony stimulating factor (rmM-CSF) to produce osteoclasts. Tumour-associated cytokines IL-1a, TNF-a, and IL-6, and the regulatory cytokine osteoprotegerin (OPG) were added to assess osteoclast cell number (cytospin analysis with TRAP staining) and function (resorption pit number on dentine slices). Short interfering sequence of RNA directed towards RANK receptor (RANK RNAi) was used to assess the effect of abrogating RANK-RANK-L signaling in this pathway.

Tumour-associated cytokines failed to significantly alter OC cell number or function in the model tested. When TNF-a, IL-1a, and IL-6 were added together, the effect on OC function was variable, without a clear trend towards OC activation. The addition of the cytokine OPG revealed a trend towards reducing OC function, but this did not reach statistical significance. RANK RNAi also revealed a trend towards reducing OC function in the presence and absence of tumour-associated cytokines.

Tumour associated cytokines failed to enhance OC function using the monocyte cell line RAW 264.7. Both OPG and RANK RNAi revealed a trend towards reducing OC function, although further testing is required to confirm this observation. Future direction with include analysis of fresh bone marrow-derived OC, which may be more appropriate for this model.

The referral time for spine surgery consultation in Halifax is approximately one year. We currently do not understand the significance of delay in surgical consultation, nor do we have documentation of patient-perceived effects of this delay. Identifying patient characteristics associated with spine pathology mandating earlier surgical intervention would have obvious benefit in streamlining this population in our referral pattern. Furthermore, outlining patient characteristics who are unlikely to benefit from orthopaedic surgical assessment for spine surgery may facilitate community management of spinal pathology and accordingly improve wait times for surgical consultation.

The aim of this study was to Identify patient variables that are predictive of need for early surgical evaluation. Also, to assess patient and surgeon satisfaction with wait times for consultation.

Demographic data and questionnaires were prospectively collected on all consenting patients seen by two orthopaedic spine surgeons over a two week period. Patient and surgeon impression of wait was documented, in addition to Oswestry Disability Index (ODI) scores, and the Visual Analogue Scale (VAS) to document pain. Surgeon reasons for scheduling or delaying surgical planning were also documented and correlated to patient scores.

The average wait time for surgical consultation was 9.7 months, with a mode of sixteen months. 62.8% of patients felt that earlier consultation would be more appropriate, while 31.1% felt that they had deteriorated due to the delay. In addition, 26% felt that the delay negatively influenced their prognosis. Treating surgeons felt that the patient should have been seen sooner in 39% of cases, and that delay in consultation negatively affected prognosis in 6.2% of cases. Of two hundred and forty-two patients completing the survey over the two week period, only ten (4.1%) were scheduled for surgery.

Both patients and physicians felt that prolonged referral-consultation wait times were unacceptable, and deleteriously affected prognosis in a significant proportion of cases. The majority of patients seen were not deemed surgical candidates, indicating room for improvement in referral patterns.

Purpose: To describe the technique and outcomes of patients requiring Lateral Gastrocnemius flaps for soft tissue coverage of the lateral side of the knee after sarcoma.

Methods: Four patients with sarcomas on the lateral knee capsule were identified. 1 patient had an Osteosarcoma of the proximal tibia resected, requiring reconstruction. 2 patients had Malignant fibrous hystiocytoma proximal to the lateral knee joint and 1 patient had a leiomyosar-coma who presented after 6 failed local resections. The length of follow up is from 13 months to 5 years, average 3.25 years. There were no graft failures. The average surface area of the resection was 118 cm2. There were two sarcoma recurrences requiring excision and radiation. There was one death due to metastases. The technique involves the releasing the gastroc flap down to the aponeurosis and then the careful dissection of the peroneal nerve with delivery of the muscle up behind the peroneal nerve to the lateral aspect of the knee. The flap is rotated fibrous layer down and the muscle readily accepts a meshed skin graft taken locally, giving this technique the advantage of reconstructing a capsule and creating a superior bed for accepting skin grafts.

Results: Average time to healing was 3.8 weeks. There have been no nerve injuries, no graft loss and all had a function range of motion. The functional results have been very reliable. Using the musculoskeletal tumour society score (MSTS) and the Toronto Extremity Salvage Scoring (TESS) system we had an average MSTS score of 21.5 with a percent of 71.5 and a TESS score of 44.5 for the living patients. These correlate to very good outcomes.

Conclusions: The lateral gastrocs flap has a reputation of being technically complex. Meller et al.(1997) report peroneal nerve injuries in 8 of 27 cases. This institution has no complications with this flap and recommends it for soft tissue defects that extend to the midline on the lateral aspect of the knee joint.

Purpose: The Advance Medial Pivot (MP) knee has higher congruency and postulated different kinematics than traditional posterior stabilized knee implants. This could lead to increased micromotion at the tibial component/bone interface potentially resulting in premature loosening. To investigate the stability of the MP knee we used maximum total point motion (MTPM) as determined with RSA to compare micromotion at the tibial component/bone interface between the Advance MP and PS knees.

Methods: A power calculation determined that a minimum sample size of 40 (20/group) was required. Sixty-six patients (48 females) with primary osteoarthritis of the knee were randomized to receive the Advance MP (n=36) or PS (n=30) knee. Three experienced knee surgeons followed a standardized surgical technique (PCL resection, patella resurfacing, RSA bead placement in polyethylene and tibia) and post-operative protocol (CPM as tolerated, no drains, WBAT). SF-36, WOMAC, PCS, KSCRS were administered to all patients pre-operatively and at 6, 12 and 24 months post-operatively and BMI was recorded. Within 4 days of surgery and at 6, 12 and 24 months post-operatively patients underwent bi-planar x-rays.

Results: Fifteen patients were lost to follow-up (2 infections, 1 death, 2 dropped out, 10 lost due to technical issues). There was no difference in MTPM between groups at 2 years. Physical function was better (p< 0.03) for the PS group at 6 months but there was no difference at 1 year.

Conclusions: There was no difference in MTPM between groups at 2 years post-op. The Advance PS knee appears to result in earlier post-operative improvements in physical function. The altered kinematics and increased congruency of the Advance MP knee does not seem to alter the forces at the tibial component/bone interface and therefore does not appear to be more prone to migration and premature aseptic loosening.

Funding : Other Education Grant

Funding Parties : Unrestricted grant from Wright Medical Inc.

Purpose: To investigate the stability of an uncemented Trabecular Metal (TM) tibial component we used maximum total point motion (MTPM) as determined with RSA to compare micromotion at the tibial component/bone interface between the uncemented Nexgen TM monoblock and cemented Nexgen cobalt chrome modular knee prostheses.

Methods: A power calculation determined that a minimum sample size of 40 (20/group) was required. Sixty-seven patients with primary osteoarthritis of the knee were randomized to receive the Nexgen TM monoblock (n=34; 20 female; mean age=66 years; mean BMI=32) or cobalt chrome modular (n=33; 19 female; mean age=65 years; mean BMI=33) posterior stabilized knees. Four experienced knee surgeons followed a standardized surgical technique (PCL resection, patella resurfacing, RSA bead placement in polyethylene and tibia) and post-operative protocol (CPM as tolerated, no drains, WBAT). SF-36, WOMAC, PCS, KSCRS were administered to all patients pre-operatively and at 6, 12 and 24 months post-operatively and BMI was recorded. Within 4 days of surgery and at 6, 12 and 24 months post-operatively patients underwent bi-planar x-rays.

Results: The TM group had greater initial migration but appeared stabilized at 1 year. There were 2 significant subgroups in the TM group based on migration at 6 months: one group had mean values of 2.1 mm while the other had mean values of 0.4 mm which was comparable to the modular group (0.6 mm). There was no significant migration between 6 and 12 months for both implants indicating good fixation to the proximal tibia. There were no differences between groups in the outcome measures, age and BMI.

Conclusions: There was no difference in MTPM between groups at 1 year post-op and all knees appeared well fixed to the proximal tibia by 6 months postop. The Nexgen TM monoblock tibial component seemed to be prone to greater initial migration but it does not appear to compromise long-term bony in-growth and fixation. Long-term survivorship of the TM tibial component should be the same or better than a cemented cobalt chrome tray.

Funding : Other Education Grant

Funding Parties : Unrestricted grant from Zimmer Inc.

Purpose: To describe our experience with vascularised fibulas used in sarcoma limb salvage surgery using standardized patient outcome measures.

Methods: All vascularised fibulas and osteochondral allografts performed in the Capital District Health authority were assessed. A complete chart review and current functional assessment of the patients using the Toronto Extremity Salvage score (TESS) and the Musculosketal Tumour Society (MSTS) score were performed.

Results: Nineteen patients with 19 tumors were recorded. The tumors range from 11 osteosarcomas, 4 Ewing’s sarcoma, 3 Malignant Fibrous Histiocytoma’s and 1 Chondrosarcoma. Average age was 23. The patient demographics are 75% male, 42% smokers, 86% femoral lesions and 13 % presented with pathological fracture. There were 9 hip fusions, 3 knee fusions, 6 intercalary grafts and one osteochondral graft. There was 21 % mortality with 21% lung mets, 20% local recurrence, 15.7% rates of amputation or infection or and non union. Allograft fracture rates of 10% were noted. Two patients underwent numerous operations (18) due to non-compliance. Rate of surgical failures defined as patients requiring re-operation after 2 years is 21%. Of 19 patients 10 are working, 4 are unable and 4 are deceased and 1 lost to follow up. Average follow up is 9.8 years (range of 4–18). Our functional results include TESS averaging 57.5 with a range of 30–105 and MSTS scores of average of 16.8 with a range of 3–28 and a percent score average of 55.8. The average score on the subjective assessment question was 4 equaling a response of accept it and would do it again. The Halifax outcome and functional data corresponds well with that in the literature.

Conclusions: The biological repair of a combination of large Allografts with Vascularised Fibula’s is an excellent long term solution for construct survival with unrestricted patient activity.

Aim: The long- term results of selective patients undergoing resection of primary malignant tumours followed by allograft arthrodesis of the hip supplemented by vascularised þbula were prospectively studied. Patients and methods: 8 patients underwent resection of the primary malignant tumor of the proximal femur followed by reconstruction with allograft arthrodesis and vascularised þbular graft. The patients were clinically assessed by MSTS functional scoring system and radiologically assessed at regular intervals. All the patients were male with a mean age of 29 years (range18–39). The diagnoses included, Ewingñs sarcoma in three patients, Osteosarcoma and MFH in two patients each and Chondrosarcoma in one patient. Results: 2 patients died of extensive systemic disease without any local recurrence. At a mean follow-up was 112 months (range 28–153), the remaining six patients scored good or excellent in the MSTS scoring system and are engaged in physically active occupations. Radiologically, in three cases there was evidence of fracture of the allograft with loosening of the screws holding the plates but without the failure of the construct. The þbular graft hypertrophied with time in all the cases. Conclusions: Our experience clearly indicates that resection arthrodesis of the hip with allograft supplemented by vascularised þbula is a useful limb salvage procedure with the þbula hypertrophying slowly with time. This is especially so in carefully selected physically active patients who have poor long-term survival with resection followed by custom-made prosthesis.

Aim: The long-term results of Cementless Total Knee Replacements have been traditionally unsatisfactory owing to the problems of þxation of the Tibial component. The purpose of this study was to evaluate the long- term results of Cementless Ortholoc I Total Knee Replacement (Wright Medical, Arlington, TN). Patients & methods: Between June 1985 and Dec.1987, 164 patients underwent 187 cementless Ortholoc I TKAs. The Knee Society scoring system was used to assess patients both clinically and radiologically. Kaplan Meier Survivorship analysis was used to assess survival with all revisions and revisions for aseptic loosening alone as end points. Results: 68 patients (83 knees) were dead and 14 were lost. 82 patients (89 knees) were followed up at a mean of 159 months (145–181). Mean age was 71 years (range 35–87) and the majority was female. OA was the commonest indication for surgery. The mean BMI was 28(range 15–46). 42 patients had a high tibial osteotomy prior to their TKA. 13 knees have been revised, 6 of which for aseptic loosening. The Knee Society score at þnal follow-up was 85 (58–98). With any revision as end point the survival at 15 years was 92% and with revision for aseptic loosening as end point it was 96%. Conclusions: Our results with the Ortholoc I TKA has been excellent with a success rate of over 96% at a mean follow-up of nearly 13 years. We believe that the better þxation of the Tibial component is a major factor inßuencing the success of this cementless design of TKA

Numerous techniques of arthrodesis of the ankle have been described in the literature with variable results. Although arthrodesis achieves satisfying results in most cases, high complication rates have been reported. We utilized a medial compression T plate to achieve fusion and the aim of this study is to present the early to mid term results of this procedure at our institution.

20 patients (23 ankles) underwent ankle arthrodesis by a single surgeon using the same surgical technique. Under tourniquet control, a medial longitudinal incision centering on the medial malleolus was used. After osteotomising the medial malleolus to expose the ankle joint, chevron cuts were made in the tibia and the talus removing only enough bone. The cut surfaces are apposed and then compressed together by using a medial compression T plate. The excised medial malleolus was used as bone graft. The fixation was protected in a plaster cast and allowed only partial weight bearing for up to 10 weeks. The ankles were clinically assessed by Mazur ankle scoring system and radiologically assessed until fusion was solid.

The mean age at operation was 56 years (range 20–76) and the sex distribution was equal. Indication for surgery included either posttraumatic or rheumatoid arthritis. At a mean follow-up of 73 months (range 6–112), all the patients had complete pain relief. Complications included deep infection in two ankles (Rheumatoid patient, needed implant removal), subtalar pain in four and nonunion in one ankle. There was late loss of position in 2 ankles (same patient), who was later diagnosed with charcot’s joints. All the fusions occurred within 16 weeks.

The fusion rate with this technique was 96% with the medial T plate providing a stable internal fixation. Our experience suggests that medial compression arthrodesis of the ankle is a reliable and an easily reproducible technique with a very low incidence of complications.

The main object of acetabular revisions is to restore bone stock and provide adequate support for the cup. Allograft bone has been used to reconstruct the acetabulum with variable results. This study is a prospective assessment of the performance of the uncemented cups with morsellized allograft bone in revision acetabular reconstruction.

A single surgeon using a direct lateral approach performed 98 acetabular revisions. An uncemented hemispherical cup with multiple screw holes and morsellized allograft bones was used in all the reconstructions. Patients were clinically assessed by Harris Hip score. Acetabular defects were classified by AAOS Classification system using standard AP pelvis x-rays. Massin’s criteria was used for assessing cup migration; evidence of screw breakage and acetabular bone incorporation were also looked for.

5 patients died before the 3-year follow-up, leaving 93 hips for final analysis. Mean age at surgery was 66 years (range 24–87). Majority of the acetabular defects belonged to AAOS type III. The mean follow-up was 76. 13 hips have undergone repeat revisions, five of which for aseptic loosening of the cup. Meantime to revision was 42 months.

Reconstruction of the bone-deficient acetabulum in revision arthroplasty of the hip is a difficult problem and no single procedure is universally good. However, the use of allograft bone provides a biological solution by restoring the bone stock. The use of uncemented cups with screws provides the primary stability that is supplemented later by the incorporated allograft bone. The rate of revisions for aseptic loosening of the cup in our series is low at 6% after a mean of 6 years. Even in these cases the repeat revisions were significantly easier due to restored bone stock.

This is a retrospective assessment of the performance of a consecutive series of the titanium uncemented Gemini femoral component. The Gemini uncemented stem (De Puy) is a modular titanium femoral stem with a cobalt chrome head. It has proximal porous coating allowing stable fixation by bony in-growth and a smooth distal stem allowing mechanical fixation.

Using a direct lateral approach, 152 consecutive patients underwent a total hip replacement using the Gemini uncemented femoral component and an unce-mented cup. Patients were regularly assessed clinically (Harris hip score) and radiologically (Engh’s criteria for fixation of the prosthesis). Kaplan Meier survivorship analysis was used to assess survival.

16 patients were lost to follow-up and 30 were dead with the THR in situ, leaving 106 hips for final analysis, at a mean follow-up of 106 months. The mean age of the group was 60 years (range 25–83) and OA was the commonest diagnosis. The mean Harris hip score improved from 34 to 92(range 83–100). 7 stems have been revised, four of which for aseptic loosening and a further two are radiologically loose. Mean time to revision was 41 months (range 14–76). By Engh’s criteria, 90% of the hips had stable bony fixation; only 4% of the patients complained of thigh pain at final follow-up. Kaplan Meier survivorship analysis with aseptic loosening as endpoint indicated a survival of 93% at 8 years.

A mid-term result with the Gemini uncemented stems at a mean follow-up of approximately 9 years was excellent. This is in sharp contrast to the cemented stem of similar design, even though the uncemented version was used in younger and more active group of patients. Titanium alloy is biocompatible allowing for excellent bony in growth, making it an ideal alloy in the manufacture of uncemented stems. Having a modulus of elasticity close to that of bone explains the low incidence of thigh pain.

This is a prospective study assessing the results of patients receiving large fragment allograft and a vascularised fibular graft following primary malignant tumour resections around the hip and the knee.

18 patients underwent tumor resection followed by reconstruction with large fragment allograft and vascularised fibular graft. Eight patients underwent resection arthrodesis of the hip, four underwent resection arthrodesis of the knee and six underwent intercalary resections. Following tumour resection with adequate margins, an appropriate sized allograft fragment was internally fixed with either a plate or an intramedullary nail. A vascularised fibular graft was used to span the gap between the remaining host bones. Osteosarcoma was the commonest diagnosis. The patients were clinically assessed by MSTS functional scoring system and radiologically assessed at regular intervals.

The mean age was 26 years (range12–70) and majority of the patients was men. 11 patients received preoperative chemotherapy. Mean follow-up was 85 months (range 8–153). Six patients have died of metastatic disease at a mean of 33 months. Complications included local recurrence in two, deep infection in one and stress fracture of the fibula in two cases. One patient with local recurrence and the other with deep infection underwent an amputation. Majority of the patients had good or excellent MSTS scores at final follow-up and 75% of the patients are engaged in physically active occupations. Graft hypertrophy was evident in majority of the patients.

Our experience clearly indicates that reconstruction with large fragment allograft and vascularised fibular graft is a useful limb salvage procedure with the fibula hypertrophying slowly with time. The eventual fracture of the allograft or failure of the allograft-plate composite is to be expected but is not deleterious due to the physiological response of the vascularised fibula to the weight bearing stresses over time. We feel that this biological solution is likely to demonstrate superior long-term results compared to a prosthetic reconstruction.

This is a retrospective assessment of the performance of the titanium cemented Gemini femoral component. The Gemini stem (DePuy) is a modular titanium femoral stem with a cobalt chrome femoral head. It has a roughened proximal surface finish to enhance cement bonding and a fixed distal centraliser.

205 total hip replacements were performed using a titanium cemented Gemini stem and an uncemented cup. All the operations were performed by a lateral approach using modern cementing technique. Patients were assessed clinically (Harris hip score) and radiologically. Kaplan Meier Survivorship analysis was used to assess survival.

8 patients were lost and 36 patients died with their total hip prosthesis in situ. The average follow-up in the remaining 161 hips was 70 months (range 37–124 months). The average age was 70 years (range 35–91). Osteoarthritis was the commonest diagnosis and majority of the patients was female. Using the Barrack’s criteria for cementing quality, more than 85% of the hips belonged either to grade A or B with an adequate proximal cement mantle. 28 hips have been revised (26 of which for aseptic loosening) and a further ten have been recognized as radiological failures. A small sized stem was used in over 85% of the failures. Mean time to revision was 3.1 years. Survival according to Kaplan-Meier Survivor curves at 6 years was 72%.

There is a high incidence of early failure associated with these cemented titanium stems (28%). The possible mechanism of failure is as follows. The rough surface finish and the flexible titanium alloy are likely to produce large amounts of wear debris and the centraliser which is fixed to the stem probably acts as an area of stress concentration causing accelerated destruction of the distal cement mantle. Based on our experience, the continued use of this cemented stem is no longer justified.