The distal humerus represents 1% of all primary bone tumours. Endoprosthetic replacement can potentially improve function and provide good pain relief. We present out experience with the custom made Stanmore elbow endoprosthesis used after resection of malignant tumours of the distal humerus. Between 1970–2009 we carried out 19 endoprosthetic replacments for malignant tumours of the distal humerus. 10 were a result of metastasis and 9 were primary bone tumours. 7 patients had a pathological fracture as their first presentation and 3 had pathological fractures after the diagnosis was made. 11 patients died between 3 months to 16 year following surgery. The mean survival of the patient group was 7.1 years (range 3 months to 37 years). 4 patients underwent a revision EPR and one patient underwent two revision EPR's due to loosening. Two patients underwent maintenance procedures (rebushing) due to wear of the poly bushing. We have had no revisions since the design of hte implant was changed to a floppy hinge design. One patient underwent an above elbow amputation four years after surgery due to local recurrence. There were no early post operative infections. One patient developed a sinus requiring multiple wound explorations, one year after insertion of the endoprosthesis for a sarcoma. This patient was infection free till the time of death 3 years later. There were no nerve palsies, periprosthetic fractures or wound problems. The mean TES score was 72% (59–78%) in the surviving patients at review. As the majority of the patients were implanted for metastatic disease the initial reliablity and low complication rate of the procedure, in our series, confirms that this is a suitable reconstruction for patients in significant metastatic pain from a destructive lesion of the distal humerus, rapidly restoring function and relieving pain in a predictable manner

We have investigated whether improvements in design have altered the outcome for patients undergoing endoprosthetic replacement of the distal femur following tumour resection. Survival of the implant and ‘servicing’ procedures have been documented using a prospective database and review of the implant design records and case records. A total of 335 patients underwent a distal femoral replacement with 162 having a fixed hinge design and 173 a rotating hinge with most of the latter group having a hydroxyapatite collar at the bone prosthesis junction. The median age of the patients was 24 years (range 13-82 yrs). With a minimum follow up of 5 years and a maximum of 30 years, 192 patients remain alive with a median follow-up of 11 years. The risk of revision for any reason was 17% at 5 years, 34% at 10 years and 58% at 20 years. One in ten patients developed an infection and 42% of these patients eventually required an amputation. Aseptic loosening was the most common reason for revision in the fixed hinge knees whilst infection and stem fracture were the most common reason in the rotating hinges. The risk of revision for aseptic loosening in the fixed hinges was 32% at ten years compared with nil for the rotating hinge knees with a hydroxyapatite collar. The overall risk of revision for any reason was halved by use of the rotating hinge, and for patients older than 40 years at time of implant. Conclusion. Improvements in design of distal femoral replacements have significantly decreased the risk of revision surgery. Infection remains a serious problem for these patients

There is very limited literature available on the use of prosthetic replacement in the treatment of primary and secondary tumours of the radius. In the past these were treated with vascularised and non-vascularised autografts which had associated donor site morbidity, problems of non union, graft or junctional fractures and delayed return to function. Our study is a mid to long term follow-up of implant survivorship and the functional outcome of metal prosthetic replacement used for primary and metastatic lesions of radius. We had 15 patients (8 males:7 females) with a mean age of 53 years. 8 patients underwent proximal radial replacement, 2 with mid-shaft radial replacement and 6 patients had distal radial replacements with wrist arthrodesis. The indications for replacement included metastatic lesions from renal cell carcinoma, primary giant cell tumours, ewings' sarcoma, chondroblastoma, radio-ulnar synostosis and benign fibrous histiocytoma. The average follow up was 5 years and 6 months (range 3 months - 18 years). Four patients died as a result of dissemination of renal cell carcinoma and two patients were lost to follow-up. There were no complications with the prosthesis or infection. Clinically and radiographically there was no loosening demonstrated at 18 years with secure fixation of implants. Two patients developed interossoeus nerve palsies which partially recovered. Functional outcomes of the elbow were assessed using the Mayo performance score with patients achieving a mean score of 85 postoperatively (range 65-95). All but one patient had full range of motion of the elbow. The patient with radio-ulnar synostosis had a 25 degree fixed flexion pot-operatively. Although the distal radial replacements had decreased range of movements of the wrist due to arthrodesis, they had excellent functional outcomes. Only one patient required revision surgery due to post-traumatic loosening of the implant. Our results of the use of endoprosthetic replacement of radius in the treatment of tumours are encouraging with regards to survivorship of the implant and functional outcome. This type of treatment results in an early return to daily routine activties, good functional outcome and patient satisfaction

Solitary plasmacytomas in the appendicular skeleton are rare monoclonal expansions of plasmacytoid cells. They are two main hazards; local destruction of bone with resultant loss of function and possible fracture, and progression to Myeloma.

Between February 1988 and July 2005 seven patients (4 male, 3 female) were treated for solitary plasmacytoma with surgical resection and endoprosthetic reconstruction. The median age was 46.7 (35-75). The site was: distal humerus (2), proximal humerus (2) proximal femur (2) proximal tibia (1). Three patients had sustained a pathological fracture. Five patients had received pre-operative radiotherapy and three received post-operative radiotherapy. Mean follow-up is 8.6 years. Two cases became infected at 2 and 5 years post-operatively and have had revisions of their endoprosthesis. Both remain functional at 18 and 15 years. No patient has suffered a local recurrence. Two patients have progressed to multiple Myeloma but no patients have died. Literature review shows that the progression of solitary bone plasmacytoma to Myeloma is around 53% despite radiotherapy, in an average period of 2-4 years. With resection and endoprosthetic reconstruction, the progression in this series has been 28% despite an average follow up of 8.6 years.

Although the numbers are small, due to the rarity of the condition, surgical resection and endoprosthetic reconstruction reduces disease progression than radiotherapy alone. This produces far superior results compared to the intramedullary nailing of the long bones for this condition. Endoprosthetic reconstruction after resection should be given consideration in cases of solitary plasmacytoma of the appendicular skeleton when there is extensive bone destruction present. The optimal timing of local radiotherapy to be combined with surgery is still to be established.

Aim. Deep infection following endoprosthetic replacement (EPR) of long bones is a devastating complication occurring in 15% of musculoskeletal tumour patients. The recently published PARITY Trial demonstrated that extending antibiotic prophylaxis from 24 hours to 5 days does not reduce infection rates. However, questions remain about the optimal antibiotic choice and dose. Method. A 23-question multiple-choice questionnaire was designed and piloted through an iterative feedback process until the final version was agreed by all authors. Open and closed-ended questions were used to gather information on practice and Likert-type scale responses were used to grade responses to ascertain surgeon perceptions and preferences. The online survey was sent to all surgeon delegates of the 34th Annual Meeting of the European Musculo-Skeletal Oncology Society in London in October 2022. Results. Amongst 61 respondents, 43 were based in Europe and 18 outside of Europe. The majority (48/61) had been in clinical practice over 11 years. Antibiotic choice. 1st or 2nd generation cephalosporins were the first line choice practiced among 49 (80.3%) of respondents. Of these, 39 responded had a 2nd line protocol for beta-lactam allergy which was most commonly clindamycin (18), vancomycin (11) or a combination of a glycopeptide or clindamycin plus gentamicin (4). Respondents changed their first line regimen for radiotherapy in 6/61, chemotherapy in 8/61 and tumour site in 20/61. Re-dosing. Intraoperative re-dosing intervals of 1st and 2nd generation cephalosporins ranged from 2 to 8 hourly. Re-dosing for blood loss ranged from never to when 2 litres was lost. Of the 47 respondents, 24 said intraoperative re-dosing is always reliably administered. Duration. Six (10%) of 61 respondent routinely cover the intraoperative period only, whereas 30 (49%) give 24 hours, 16 (give 48 hours or longer and 8 continue until surgical drains are removed. 31 of 61 change duration depending on clinical situation. The most common reasons for changing were patient risk factors, soft tissue status and previous radiotherapy. 57/61 surgeons were aware of the PARITY Trial. When these respondents were asked whether they had changed practice based on PARITY, 12 said yes, 24 said no and 21 said they always give 24 hours anyway. Conclusions. Amongst an international cohort of orthopaedic oncology surgeons there was a wide variation in practice. Further research should focus on the optimum choice and re-dosing strategy, which have not been defined

Since 1970, 2200 primary endoprosthetic replacements have been carried out at our Unit for bone tumours. 3% were carried out in the 1970s, 21% in the 1980s, 33% in the 1990s and 43% since 2000. The most common diagnosis was osteosarcoma (839)(38%) followed by metastatic disease (18%) and chondrosarcoma (13%). The most common site was the distal femur (35%) followed by the proximal femur and proximal tibia. The least common sites were the scapula and distal radius. The mean age at operation was 35 but varied widely, being 19 in patients with osteosarcoma and 58 for those with metastases. 239 extendable prostheses were inserted in children. 50% of the patients were alive at 10yrs and 42% at 20yrs. 7% required an amputation either for local recurrence or infection. The failure rate of the prostheses varied by age and site, with pelvic and proximal tibial replacements having the highest risk of infection and proximal humeral replacements the lowest risk of any complication. The failure rates of the most common prostheses (distal femur and proximal tibia) have improved over time and are now ~ 1.5% per year. Hydroxyapatite collars have largely resolved the problem of aseptic loosening. Silver coated prostheses have been used in 48 complex cases with encouraging results in controlling infection. Functional scores averaged 80% and were the same for revision as for primary implants. Conclusion. Significant improvements of design have improved endoprosthetic replacements for tumours. Results are now fairly predictable but still not as good as primary joint replacemenrts. Infection remains the most serious challenge

Aim. We outline a treatment protocol for subjects with chronic periprosthetic joint infections (PJI) who elected not to have surgery. We developed a method of serial “fluid-depleting” aspirations with intra-articular gentamycin injections to affect the population of the biofilm community. We have experienced many treatment failures, as expected, but have also had a group of subjects who responded exceptionally well, requiring no surgical intervention. Our longest follow-up is 10 years. Method. From June 2009 to December 2018, 372 clinical cases of chronic PJI involving primary and revision TKA and THA were treated. Of these, 25 subjects were treated with an active suppression protocol, in lieu of surgery. The protocol entailed frequent aspirations and intra-articular antibiotic injections to quell the PJI inflammatory response. All aspirations were performed by the treating surgeon in the orthopaedic clinic without fluoroscopic guidance. Based on a subject's response to the protocol, he/she was identified as 1 of 3 classifications: 1) Ongoing Treatment – Biofilm Trained (OTBT), 2) Ongoing Treatment – Biofilm Untrained (OTBU), and 3) Treatment Failure (TF). OTBT subjects showed no clinical signs of infection. Serum biomarkers (CRP, ESR) remained consistently normal and subjects were not on oral suppressive antibiotics. Aspiration analysis and cultures remained negative. Maintenance treatment consisted of a fluid-depleting aspiration with an intra-articular gentamycin injection every 12–16 weeks. OTBU subjects showed improved clinical symptoms, lowered serum biomarkers, and lowered WBC counts, but still demonstrated objective signs of infection. TF subjects did not respond to the protocol and showed unchanged/worsening clinical symptoms. Results. Of the 25 subjects, 8 were THA's and 17 were TKA's. Of these cases, 21 (84%) were endoprosthetic replacements. 8 subjects (32%) were classified as OTBT, 6 (24%) as OTBU, and 11 (44%) as TF. All TF subjects were treated with a two-stage exchange protocol. Conclusions. This study is the first describing the potential of modifying bacterial biofilm in a chronic PJI. While our success rate was modest (32%), “Biofilm Trained” subjects demonstrated dramatic changes. Subjects led normal lives, only minimally disrupted by an aspiration and injection every 3–4 months. In the future, we are looking at different agents to modify the enveloping biofilm, including a pre-aspiration injection of EDTA to disrupt the biofilm surface, followed by injecting benevolent bacteria to transform the biofilm to a benevolent state. If able to achieve such a state in a consistent fashion, the impact on the patient and healthcare communities would be enormous

Endoprosthetic replacement (EPR) is an available option for the management of massive bone loss around failed knee implants. The aim of this study was to determine the results of knee EPRs performed for non-tumour indications. Since 2007, 85 EPRs were performed for in a single tertiary centre by seven surgeons. Mean age at surgery was 73.5 years (range:35–95) with infection as the most common indication (49%), followed by aseptic loosening (18%), complex primary replacement (16%), fracture (15%) and mechanical failure (2%). Mean follow up was 4 years (range:1–9). Functional outcome was determined using the Oxford Knee Score (OKS). At follow-up, 21 patients were deceased and 2 lost to follow-up. Complication rate was 19%. Of the 7 infected cases, 6 were treated with DAIR (debridement, antibiotics, and implant retention) and one underwent above knee amputation. Four of the patients undergoing DAIR were cleared of infection and 2 are on long-term antibiotics. Accounting for implant revision, loss to follow-up and those on long-term antibiotics as failures, 5-year survival was 89% with an average OKS of 25 (SD=10). This mid-term study shows that distal femur EPR is a valuable option for the increasing burden of complex revision knee surgery

Femoral neck fractures continue to be one of the most common orthopaedic injuries treated today. Owing to the increased longevity of patients, enduring activity of older patients, and widespread osteoporosis in the population, there are more femoral neck fractures treated nowadays than ever before. Over 1 million femoral neck fractures were treated in the >65-year-old population, in the United States, between the years 1991–2008. The treatment of femoral neck fractures is unique because some fractures are amenable to internal fixation, while others require endoprosthetic replacement, either with a hemiarthroplasty or total hip replacement. Traditionally, less displaced fractures are treated with internal fixation; however, in younger patients, an attempt to fix the displaced fractures may be performed, in order to avoid a joint replacement in this population. The age at which an attempt at internal fixation is performed is still controversial, and treatment must be individualised to each patient. In general, patients younger than 60 would likely have internal fixation of the femoral neck fracture, rather than joint replacement. The paradigm for the treatment of femoral neck fractures has been changing in the last 10 years, due to advances in implant technology, surgical technique, and scientific papers that have compared the results of all three treatment options. Larger diameter femoral heads in combination with highly crosslinked polyethylene, or dual mobility head options, provide greater joint stability today than was possible in the past, thus making THA a more appealing option. Furthermore, greater use of the direct anterior approach to THA may also reduce the postoperative dislocation rate, due to preservation of the posterior capsule and short external rotators. Therefore, the author will propose the use of arthroplasty for displaced femoral neck fractures in patients younger than 60 years of age, owing to the reliability and reproducibility of THA over ORIF. Furthermore, the advances in arthroplasty materials and surgical techniques can restore function in this group of younger patients, with greater longevity of the implant than in the past

Introduction. The burden of peri-prosthetic joint infection (PJI) following hip and knee surgery is increasing. Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. Aims. To determine clinical outcome of EPRs for treatment of PJI around the hip and knee joint. Methods. This was a retrospective consecutive case-series of hip and knee EPRs between 2007–2014 in our tertiary unit for the treatment of PJI following complex arthroplasty or fracture fixation. Data recorded included indication for EPR (infected primary/revision arthroplasty, infected non-union/failed osteosynthesis, gross bone loss following native joint infection), number of previous surgeries, and organism identified. Outcome measures included PJI eradication rate (with failure defined as EPR revision, amputation, or being on life-long suppressive antibiotics), complications, implant survival, mortality, and functional outcome (Oxford Hip/Knee Score; OHS/OKS). Results. 58 EPRs (32 knee and 26 hip) were performed with a mean age of 68 years (range: 35–92). The mean number of previous surgeries prior to EPR was 3.4 (range: 1–10). At mean follow-up of 3.5 years, 11 (19%) patients were deceased. EPR was implanted as a two-stage procedure in 76% of cases. Plastic surgical involvement and flap coverage was necessary in 11 cases. Polymicrobial growth was detected in 40% of cases, followed by Coagulase-negative staphylococci (26%). The overall complication rate was 40%. Recurrence of infection post-EPR occurred in 14 patients (24%); 5 were treated with Debridement, Antibiotics and Implant Retention (DAIR), 3 with revision, 1 with above-knee amputation and the remaining 6 remained on long-term suppressive antibiotics. PJI eradication was achieved in 44 (76%) cases (69% knees and 85% hips). Of the remaining 14 cases, 9 remain on long-term antibiotics. The complication rate was similar in knees (41%) and hips (38%). PJI eradication was more successful in hips (85%) compared to knees (69%). To date, 6 EPRs have been revised (10%). The overall 5-year implant survivorship was 83% (95% CI: 68–98%). The mean OHS was 25 (range 7–39.) and the mean OKS was 20 (range 6–43), the best possible score being 48. Conclusions. This mid-term study provides further support for the use of massive endoprostheses in the eradication of PJI in complex, previously multiply revised cases with subsequent limb salvage (in all but one case). We describe PJI eradication rate of 76% with acceptable functional outcomes. This eradication rate is comparable to that following treatment of PJI associated with standard arthroplasty

Introduction:. Endoprosthetic replacement of the proximal femur is common in the management of bone tumours and failed revision arthroplasty. This study seeks to compare those patients undergoing acetabular resurfacing at the time of femoral replacement with those patients where the native acetabulum was preserved. Methods:. All proximal femoral replacements from 2004 to 2009 with a five year follow up were included. Case files were interrogated to identify those that had either revision surgery or dislocation of the hip. Results:. 87 patients met the inclusion criteria with an average age of 53 years. 25 operations were for failed revision arthroplasty, 61 for tumours and 1 for osteomyelitis. In 60 patients the acetabulum was resurfaced at surgery, and in 27 patients the acetabulum was preserved. 36 of 60 patients (60%) undergoing immediate resurfacing of the acetabulum had tumours. In patients who did not undergo acetabular resurfacing at surgery 4 sustained dislocations; 1 had surgery for failed revision arthroplasty and 3 tumour resections. Dislocations were significantly lower in the group undergoing immedicate resurfacing p<0.05. There were no dislocations in the acetabular resurfacing cohort p=0.0034. Eighteen of the 87 patients underwent revision surgery (20.7%) although none of these were for recurrent dislocation. 9 of the 27 patients (33.3%) that had a native acetabulum went on to have revision surgery in comparison with 9 (15%) revisions performed in those undergoing acetabular resurfacing at the time of surgery p= 0.02. 83% of revisions were for acetabular wear p<0.05. Conclusions:. Revision and dislocation rates for proximal femoral replacement are significantly lower in those who undergo resurfacing of the acetabulum

Femoral neck fractures continue to be one of the most common orthopaedic injuries treated today. Owing to the increased longevity of patients, enduring activity of older patients, and widespread osteoporosis in the population, there are more femoral neck fractures treated nowadays than ever before. Over 1 million femoral neck fractures were treated in the >65 year old population, in the United States, between the years 1991–2008. The treatment of femoral neck fractures is unique because some fractures are amenable to internal fixation, while others require endoprosthetic replacement, either with a hemiarthroplasty or total hip replacement. Traditionally, less displaced fractures are treated with internal fixation; however, in younger patients, an attempt to fix the displaced fractures may be performed, in order to avoid a joint replacement in this population. The age at which an attempt at internal fixation is performed is still controversial, and treatment must be individualised to each patient. In general, patients younger than 60 would likely have internal fixation of the femoral neck fracture, rather than joint replacement. The paradigm for the treatment of femoral neck fractures has been changing in the last 10 years, due to advances in implant technology, surgical technique, and scientific papers that have compared the results of all three treatment options. Larger diameter femoral heads in combination with highly crosslinked polyethylene, or dual mobility head options, provide greater joint stability today than was possible in the past, thus making THA a more appealing option. Furthermore, greater use of the direct anterior approach to THA may also reduce the post-operative dislocation rate, due to preservation of the posterior capsule and short external rotators. Therefore, the author will propose the use of arthroplasty for displaced femoral neck fractures in patients younger than 60 years of age, owing to the reliability and reproducibility of THA over ORIF. Furthermore, the advances in arthroplasty materials and surgical techniques can restore function in this group of younger patients, with greater longevity of the implant than in the past

The surgical approach that is adequate for a primary total hip replacement may need to be modified to achieve a more extensile exposure as required for the revision procedure. A straightforward revision total hip replacement procedure can become quite complex when implant removal is attempted without adequate skill, instrumentation, or exposure. The most commonly used approaches in total hip replacement revision surgery are the transtrochanteric, posterolateral, and anterolateral. Although the effects of these approaches on the long-term clinical survival of the prosthetic composite are not completely clear, surgical approach does affect dislocation rates, trochanteric nonunion rates, and other indicators of clinical success. Transtrochanteric Approach - Three variations of the transtrochanteric approach exist: A) The classic Charnley trochanteric approach was popularised by virtue of its use in primary total hip arthroplasty (THA) and, therefore, was easily applied to revision THA. This approach allows excellent visualization of the lateral shaft of the femur, thus enhancing implant and cement removal. However, the classic Charnley approach is associated with a high incidence of trochanteric nonunion. Reattachment of the atrophied trochanteric fragment often requires adjunct fixation such as cables, hooks, or bolts. These devices can subsequently break, migrate, or generate particulate debris which, in turn, is capable of producing extensive granuloma. B) The trochanteric slide is accomplished by an anteromedial inclination of the osteotomy, thus providing a more stable interface for reattachment. The trochanteric slide offers the advantage of maintaining muscle continuity. The disadvantage of this technique is decreased visualization of the acetabulum. Adjunct fixation of the trochanter is also required with this approach. C) By creating a 6 cm to 12 cm distal extension to the trochanteric fragment, a large lateral window is developed which enhances both prosthesis and cement removal. Subsequently, trochanteric fixation is enhanced because the extended fragment increases the surface area available for fixation. Because the extended trochanteric osteotomy requires a larger bone resection, proximal femoral bone stock can be compromised. As a result, proximal prosthetic support with a tapered device can force the trochanteric fragment laterally, increasing the likelihood of nonunion. When an extended trochanteric osteotomy is used, the patient's postoperative physical therapy and rehabilitation course should be modified to protect the healing trochanteric fragment. Posterolateral Surgical Approach is used commonly in revision THA. The technique is popular because it is used widely for endoprosthetic replacement in the treatment of subcapital fractures. Also, the posterolateral approach is quite popular for primary THA. This approach has the advantage of maintaining the integrity of the abductor mechanism. Although femoral exposure is adequate, acetabular exposure can be limited. Also, this approach is associated with an increased incidence of dislocation. Another concern is its close proximity to the sciatic nerve, thus predisposing the patient to the risk of nerve injury. Anterolateral Surgical Approach has the advantage of improved visualization of the acetabulum and femur without the attending trochanteric complications and proximity to the sciatic nerve. This approach is associated with a low incidence of dislocation. However, the abductor muscle is divided or split and, therefore, abductor dysfunction can occur post-operatively. There also can be an increased incidence of heterotopic ossification, but it avoids the problem of trochanteric nonunion

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation; three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

Background. The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. Materials and methods. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Results. Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation, three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. Discussion. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

Between 1966 and 2001, 1254 patients underwent excision of a bone tumour with endoprosthetic replacement. All patients who had radiotherapy were identified. Their clinical details were retrieved from their records. A total of 63 patients (5%) had received adjunctive radiotherapy, 29 pre-operatively and 34 post-operatively. The mean post-operative Musculoskeletal Tumor Society scores of irradiated patients were significantly lower (log-rank test, p = 0.009). The infection rate in the group who had not been irradiated was 9.8% (117 of 1191), compared with 20.7% (6 of 29) in those who had pre-operative radiotherapy and 35.3% (12 of 34) in those who radiotherapy post-operatively. The infection-free survival rate at ten years was 85.5% for patients without radiotherapy, 74.1% for those who had pre-operative radiotherapy and 44.8% for those who had post-operative radiotherapy (log-rank test, p < 0.001). The ten-year limb salvage rate was 89% for those who did not have radiotherapy and 76% for those who did (log-rank test, p = 0.02). Radiotherapy increased the risk of revision (log-rank test, p = 0.015). A total of ten amputations were necessary to control infection, of which nine were successful. Radiotherapy may be necessary for the treatment of a bone sarcoma but increases the risk of deep infection for which amputation may be the only solution

Propionibacteria are organisms of low virulence, although they do cause deep periprosthetic infections. The aim of this study was to show that Propionibacteria do not always cause a significant rise in ESR and CRP. Between May 2001 and May 2004, we identified 77 patients with prosthetic joint replacements colonised with Propionibacteria, 47 males and 30 females. There were 47 hip joint replacements, 27 knee joint replacements, 2 endoprosthetic replacements of the femur and 1 shoulder joint replacement. We retrieved successfully the medical records of 66 patients in order to identify the number of patients treated for an infected prosthetic joint arthroplasty. The pre-operative values of ESR and CRP were recorded. For the purposes of this study, an ESR rate of 30mm/hr or higher and a CRP level of 10mg/lt or higher were considered to be suggestive of infection and were deemed a positive result. All of the 77 patients had both ESR and CRP measured pre-operatively. In only 16 (21%) both ESR and CRP were higher than 30mm/hr and 10mg/l respectively. In 33 patients (43%) with prosthetic joint replacements colonised with Propionibacteria, the pre-operative values of ESR and CRP were normal. 23 patients were treated for an infected prosthetic joint arthroplasty. In 7 (30%) of those patients both ESR and CRP were normal. This suggests that normal pre-operative values of ESR and CRP in suspected failed prosthetic joint replacements might not exclude infection, if the causative organism is of low virulence such as Propionibacteria

Segmental excision of long-bone sarcomas can require complex reconstruction, often resulting in the use of prosthetic replacements at a young age. The use of vascularised free fibula grafting (VFFG) is well established as a reconstruction modality in sarcoma surgery. Aims. To analyse the experience of two European sarcoma centres and their use of vascularised free fibula grafting as a primary and revision procedure in limb salvage for diaphyseal long-bone defects in sarcoma surgery. Methods. A retrospective analysis was carried out of 70 consecutive patients undergoing VFFG between 1996 and 2009 under the Oxford Sarcoma Service (Nuffield Orthopaedic Centre) and the Dutch Orthopaedic Tumour Society (Leiden University Hospital). Clinical and radiological assessments were made and functional outcome scores collected. Results. 70 patients, 42 male, with a mean age of 20 years (3–61) received a VFFG (a primary procedure in 76%) and underwent mean follow up of 82 months (11–181). 83% of grafts were located in the lower extremity with 71% resulting from reconstruction of malignant tumours. VFFGs with a mean length of 17.4 cm (6–25) were used to reconstruct defects with a mean length of 13.5 cm (8–21). 92% of VFFGs achieved union at mean of 59 weeks (16–250). Predictors for non-union included defects greater than 12cm, malignant disease processes and an immature skeleton. 65% of patients had at least one complication with 51% requiring at least one revision procedure, although only 3 required removal of the graft (2 endoprosthetic replacements and 1 amputation). Mean MSTS score at final follow-up was 26.7 (20–30). Conclusion. The vascularised free fibula graft has been proven to provide a stable reconstruction of bony defects after tumor resection and results in a functional extremity, however it is accompanied by a high risk of complications and revision surgery

Introduction. Despite the advances in adjuvant chemotherapy and surgical techniques, the diagnosis of a bone tumour still carries with it a significant risk of mortality. This study investigates factors affecting survival, in patients treated for malignant tumours of bone using Endoprosthetic replacement (EPR). Methods. Our tertiary referral musculoskeletal tumour unit has taken referrals over 40 years. Electronic patient records have been prospectively kept on all patients seen since 1986 and data has been entered retrospectively for patients seen between 1966 and 1986. A consecutive series of 1264 patients underwent endoprosthetic reconstruction; after 158 patients were excluded, 1106 patients were left in the study group. Factors including diagnosis, size of tumour, surgical margins, percentage tumour necrosis following chemotherapy, tumour site, local recurrence, decade of reconstruction, fracture and post-operative deep infection were analysed. Results. Overall population survival was 58.4% at 5 years, 50.5% at 10 years and 44.6% at 20 years. Significant prognostic factors on cox-regression analysis included locally recurrent disease (p<0.001), metastatic disease (p<0.001), chemotherapy (p<0.001), percentage tumour necrosis after chemotherapy (p=0.001), tumour size (p<0.001), post-operative surgical margin (p<0.001), fracture (p<0.001) and post-operative deep infection (p=0.05). Univariate analysis showed proximal femoral site (p=0.01) and EPRs after 1991 (p=0.05) were significant factors. Patients diagnosed with a deep infection within 2.5 years from implantation had 63.2% 10 year survival, compared to 49.4% in the non infected group. When stratified by diagnosis this was significant in patients with myeloma (p=0.01) and a showed strong trend in those with osteosarcoma (p=0.1). Trends towards better survival with Staphylococcal infections (p=0.2) were not demonstrated with other organisms. Discussion and conclusion. Several known prognostic factors were demonstrated for malignant bone tumours but there was evidence for increased survival after deep post-operative infection. The authors feel the results of this study and other recent evidence warrant further investigation

The medial patellofemoral ligament (MPFL) has been recognised as the most important medial structure preventing lateral dislocation or subluxation of the patella (LeGrand 2007). After MPFL rupture the patella deviates from the optimal path resulting in an altered retropatellar pressure distribution. This may lead to an early degeneration with loss of function and need for endoprosthetic joint replacement. The goal of this study was to develop a dynamic knee-simulator to test the influence of ligament instabilities to patella-tracking under simulation of physiological quadriceps muscle loading. On 10 fresh-frozen cadaveric knees the quadriceps muscle was divided into five parts along their anatomic fibre orientation analogous to Farahmand 1998. The muscular loading was achieved by applying weights to each of the fife components in proportion to the cross sectional muscle area. A total of 175 N was connected to the muscles using modified industrial cable connecting systems [Lancier Calbe, Drensteinfurt/Germany]. A novel light digital patellar reference base (DRB) was developed and attached to the patella with four bone screws. On addition a femoral and tibial digital reference base was constructed and secured to these two bones. Position data of the patella, the femur and tibia was tracked by a conventional tracking system [Optotrak, NDI Europe]. The relative movement between femur and tibia (“flexion path”) and patella and femur (“patella tracking”) was recorded. For retropatellar pressure measurement a custom made sensor was introduced between the patella and femur [Pliance, Novel/Germany]. The sensor consists of 85 single pressure measuring cells. The robot-control-unit is liked to a force-torque sensor (hybrid method). The force free knee-flexion-path from 0° to 90° was calculated during three “passive path” measurements using this hybrid robotic method. The actual measurements followed with identical parameters. The 3D-patella position was recorded (six degrees of freedom) along with the corresponding retropatellar pressure distribution according to knee-flexion and medial forces (intact vs. cut MPFL). Measurements were performed for the intact knee (“native”), with muscular quadriceps loading, after opening the joint capsule and with introduced pressure sensor to differentiate each of their influences. The load free knee-flexion-path (“passive path”) could be calculated for all of the ten knees and was utilised as the basis for all dynamic measurements. There was no alteration of the “flexion-path”. Thus the measurements were only influenced by the variables “capsular joint opening,” “muscular quadriceps loading” and “MPFL-tension”. The custom made connections between the five quadriceps components and weights proved to be a secure way to prevent rupture due to the applied forces of up to 70 N during the average measuring time of 7.5 h/knee. Only on one knee the Vastus lateralis obliquus muscle ruptured proximally. All reference bases were 100% visible despite the knee flexion form 0°–90°. No loosening of the reference base screws occurred. Overall the combination of a robotic-assisted, force free dynamic knee-flexion under quadriceps simulation and 3D-patella-tracking seems to be a promising method to evaluate the biomechanical influences of ligaments on the human knee