Background

There has been a trend in the evolution of total hip arthroplasty towards increased modularity, with this increase in modularity come some potentially harmful consequences. Modularity at the neck shaft junction has been linked to corrosion, adverse reaction to metal debris and pseudotumor formation.

The aim of this retrieval study is to assess whether the surface integrity of the polyethylene (PE) liner is affected by metal wear debris in a single implant design series of THA revised for trunnionosis.

Introduction

Native hip joint infection can result in hip arthrosis as a complication requiring the need for subsequent arthroplasty. There is little evidence to support single or staged THA. We present the results of patients who have undergone total hip arthroplasty (THA) following hip joint sepsis in our institution.

Local recurrence along the biopsy track is a known complication of percutaneous needle biopsy of malignant musculoskeletal tumours. In order to completely excise the track with the tumour its identification is essential, but this becomes increasingly difficult over time. In an initial prospective study, 22 of 45 patients (48.8%) identified over a three-month period, treated by resection of a musculoskeletal tumour, had an unidentifiable biopsy site at operation, with identification statistically more difficult after 50 days. We therefore introduced the practice of marking the biopsy site with India ink. In all 55 patients undergoing this procedure, the biopsy track was identified pre-operatively (100%); this difference was statistically significant. We recommend this technique as a safe, easy and accurate means of ensuring adequate excision of the biopsy track.

Cite this article: Bone Joint J 2013;95-B:250–3.

The aim of this study is to investigate whether MoM implants result in more chromosome aberrations and increased blood metal ions postoperatively whe compared to MoP implants.

MoM arthroplasties are being inserted in increasing numbers of younger patients due to the increased durability and reduced requirements for revision in these implants. Recent studies have raised many concerns over possible genotoxicity of MoM implants.

This is a prospective study of patients who have undergone elective total hip replacement, they were selected and then randomised into two groups. Group A received a MoP implant and group B received a MoM implant. Patients are reviewed pre-operatively (control group), at 3 months, 6 months, 1 year and 2 years post-operatively. On each occasion blood tests are taken to quantify metal ion levels (chromium, cobalt, titanium, nickel and vanadium) using HR-ICPMS method and chromosome aberrations in T lymphocytes using 24 colour fluorescent in situ hydridisation (FISH).

51 patients have been recruited to date, 23 of whom had MoP prosthesis and 28 a MoM. 47 of these had their 1 year follow-up with blood analysis and 38 have had 2 year follow up. There appeared to be a bedding period for both MoM and MoP groups, with an increase in metal ion release. The blood concentration of chromium, cobalt and titanium rise significantly in the MoM group at the 2 year stage. Chromosome aberrations occurred in both groups. Both the MoM and MoP groups showed increase frequency of aneuploidy aberrations and structural damage. The greatest increase in metal ion levels occurred at the 1 to 2 year interval corresponding to significant rise in chromosome aberrations.

Preliminary results of this study show that the levels of chromium, cobalt and titanium are significantly higher in the MoM group compared to the MoP group. This corresponds to increases in chromosome aberrations in the groups with increases in structural chromosome damage after two years.

The aim of this study is to investigate whether Metal-on-Metal (MoM) implants result in more chromosome aberrations and increased blood metal ions post-operatively when compared to Metal-on-Polyethylene (MoP) implants. Metal-on-metal arthroplasties are being inserted in increasing numbers of younger patients due to the increased durability and reduced requirement for revision in these implants. Recent studies have raised many concerns over possible genotoxicity of MoM implants. This is a prospective study of patients who have undergone elective total hip replacement, they were selected and then randomised into two groups. Group A received a MoP implant and group B received a MoM implant. Patients are reviewed pre-operatively (control group), at 3 months, 6 months, 1 year and 2 years post-operatively. On each occasion blood tests are taken to quantify metal ion levels (chromium, cobalt, titanium, nickel and vanadium) using HR-ICPMS method and chromosome aberrations in T lymphocytes using 24 colour fluorescent in situ hybridisation (FISH). 53 patients have been recruited to date. 24 of whom had MoP prosthesis and 29 a MoM. 37 of these have had their one year follow-up with blood analysis and 14 have had 2 year follow up. Cobalt and chromium concentration increased during the first 6 months in both MoM and MoP groups, in the MoM group the chromium levels were twice that of MoP group and 12x that of the preoperative samples. Chromosome aberrations occurred in both groups. At 6 months both the MoM and MoP groups showed increase frequency of aneuploidy aberrations with further increases after one year. Structural damage in the form of translocations occurred in the MoM group after one year, but not in the MoP group, by two years there was a profound increase in translocations Preliminary results of this study show that the levels of chromium and cobalt are significantly higher in the MoM group compared to the MoP group. This corresponds to increases in chromosome aberrations in the groups with increases in structural chromosome damage after two years.

There is limited literature available on the use of metal prosthetic replacements for the treatment of non-traumatic lesions of the proximal radius. This study discusses the implant survivorship and the functional outcome of the elbow following insertion of metal proximal radius endoprostheses performed at the Royal National Orthopaedic Hospital.

We present a series of six patients treated with endoprosthetic reconstruction of the proximal radius following resection of non-traumatic pathologies. The patients included four females and two males, with a mean age of 39 years at the time of surgery. Their diagnoses included Ewing’s sarcoma, chondroblastoma, benign fibrous histiocytoma, radio-ulna synostosis and renal carcinoma metastases in two patients. Follow-up extended to 192 months with a mean of 76 months. During this time there were no complications with the prostheses, the most recent radiographs demonstrated secure fixation of the implants and none required revision. One patient developed posterior interosseuous nerve neuropraxia following surgery, which partially recovered, and another patient passed away as a result of disseminated metastatic renal cell carcinoma which was present preoperatively.

The patient with radio-ulna synostosis had a 25° fixed flexion deformity of the elbow post-operatively but good flexion, supination and pronation. All other patients had full ranges of movement at the elbow.

Functional scores were assessed using the Mayo Elbow Performance Score with patients achieving a mean score of 86 out of 100.

The results of the use of proximal radial endoprostheses for treatment of non-traumatic lesions are encouraging with regards to survivorship of the implant and functional outcome of the elbow.

Metal-on-metal arthroplasties are being inserted in increasing numbers of younger patients due to the increased durability and reduced requirement for revision in these implants. Recent studies have raised many concerns over possible genotoxicity of MoM implants. This is a prospective study of patients who have undergone elective total hip replacement, they were selected and then randomised into two groups. Group A received a MoP implant and group B received a MoM implant. Patients are reviewed pre-operatively (control group), at 3 months, 6 months, 1 year and 2 years post-operatively. On each occasion blood tests are taken to quantify metal ion levels (chromium, cobalt, titanium, nickel and vanadium) using HR-ICPMS method and chromosome aberrations in T lymphocytes using 24 colour fluorescent in situ hybridisation (FISH).

Fiffty three patients have been recruited to date, 24 of whom had MoP prosthesis and 29 a MoM. 25 of these have had their one-year follow-up with blood analysis. Cobalt and chromium concentration increased during the first 6 months in both MoM and MoP groups, in the MoM group the chromium levels were twice that of MoP group and 12x that of the preoperative samples. There was no difference with the levels of titanium, nickel and vanadium. Chromosome aberrations occurred in both groups. At 6 months both the MoM and MoP groups showed increase frequency of aneuploidy aberrations with further increases after one year. Structural damage in the form of translocations occurred in the MoM group after one year, but not in the MoP group.

Preliminary results of this study show that the levels of chromium and cobalt are significantly higher in the MoM group compared to the MoP group. This corresponds to increases in chromosome aberrations between the groups particularly in translocations present in the MoM group at 1 year.

Introduction: Primary or secondary bone tumours of the distal tibia are uncommon. Before the development of endoprostheses in the 1970’s, the primary treatment for these was below knee amputation. Limb salvage is now possible without adversely affecting survival largely due to improvements in chemotherapy. We report the clinical and functional outcome of six patients who underwent limb salvage with endoprosthetic reconstruction of the distal tibia and ankle joint for malignancy.

Methods: Retrospective review of all patients who underwent limb salvage with endoprosthetic reconstruction of the distal tibia and ankle joint at our institution. Data was collected from the bone tumour database, medical records, imaging studies, clinic reviews and individual structured patient questionnaires. MSTS and TESS scores were used to assess functional outcome.

Results: Six patients underwent distal tibial replacement for malignant bone tumours of the distal tibia. There were 4 males and 2 females with a mean age of 31.2 years (range 13 to 68) and mean follow-up of 35 months (range 13 to 76). One patient died of non-neoplastic disease at 76 months. Two patients had Ewings sarcoma, two had osteosarcoma, one had malignant fibrous histiocytoma and one had adamantinoma.

No patient had metastases at presentation and no patient developed local recurrence or distant metastases post-operatively. Four patients developed infection, for which two required below knee amputation and two suppressive antibiotics. Hardware failure was seen in one patient with infection which was managed by below knee amputation. One patient required sub-talar fusion and calcaneal osteotomy for persistent ankle pain.

A child who underwent the procedure age 13 developed a 5 cm leg-length discrepancy once skeletally-mature. Mean MSTS and TESS scores for the three patients who still had a functioning endoprosthesis were 77% and 79% respectively.

Conclusion: Limb salvage with distal tibial combined with ankle joint replacement can be used as an alternative to below knee amputation in patients with bone tumours of the distal tibia. Due to the difficulties in achieving adequate soft tissue cover, patients should be counselled regarding the high potential complication rate which can lead to significant morbidity, functional deficit and further surgical intervention.

This case highlights the close association between osteo-fibrous dysplasia (OFD) and adamantinoma, drawing attention to the role for more radical treatment options when treating OFD. We discuss the advancements in joint-sparing endoprostheses using bicortical fixation. Finally we describe a unique biomedical design allowing for manufacture of an end cap to allow amputation through a custom made joint-sparing proximal tibial replacement as opposed to an above knee amputation.

A 37 year old presented 7 years ago having sustained a pathological fracture of her tibia. Subsequent biopsy revealed OFD, curettage with bone graft was performed. She later developed recurrence, two percutaneous biopsies confirmed OFD. 6 years following her initial diagnosis she was referred to RNOH with further recurrence, a biopsy at this stage revealed a de-differentiated adamantinoma. A joint-sparing proximal tibial replacement was performed and adjuvant chemotherapy administered, she remained well for one year. Recurrence was noted at the distal bone-prosthesis interface, histology revealed a high grade dedifferentiated osteosarcoma, limb preservation was not deemed possible and an amputation was performed through the prosthesis. The proximal tibial device was uncoupled leaving a residual 7 cms insitu, a small custom made end cap was attached to the remaining prosthesis and a myocutaneous flap fashioned over it, this ultimately enabled the patient to mobilise well with a below–knee orthotic device.

This case highlights the need for more radical surgery when treating cases of OFD and the relationship between OFD and adamantinoma. It also introduces a joint-sparing proximal tibial device for use in proximal tibial tumours that do not invade the proximal tibial metaphysis. The biomechanical design solution has given us the unique option of preserving the knee joint allowing the patient a below knee amputation whereas previously an above knee amputation would have been performed thereby significantly reducing her functional outcome.

Elastofibroma dorsi is a rare, benign, slow-growing ‘pseudotumour’ classically presenting as an ill defined mass at the inferior pole of the scapula. Typical symptoms include mass, pain, scapular snapping and impingement like features. There is a predilection for females after the fifth decade of life. The aetiology is unclear.

We identified 15 patients (21 tumours) with a diagnosis of elastofibroma. Seven lesions were found on the left side and fourteen on the right; bilateral lesions were found in six patients. The male:female ratio was eight:seven and mean age at presentation was 60.9 years (range 40 – 71). The mean duration of symptoms (most commonly pain, mass and scapular snapping) prior to presentation was 25.8 months. Eighteen tumours were excised with a mean follow-up of 4.2 years (0.25–16). Four lesions were diagnosed by combined MRI and CT guided biopsy, the remainder identified using MRI alone. All patients were asked specifically about symptoms, occupation, family history and employment history (including hobbies). Pain was assessed using the Visual Analogue Score (VAS) and functional outcome using the Stanmore Percentage of Normal Shoulder Assessment (SPONSA) Score. Range of forward flexion of the shoulder joint was also assessed.

In the operative group, the mean VAS score improved from 4.6 (0–10) pre-operatively to 2.5 (0–8) post-operatively. Mean SPONSA scores improved from 61.5% (20 – 100) to 81.8% (30 – 100). Mean pre-operative forward flexion was 135 degrees (70 – 180), this improved to 166 degrees (100 – 180) post-operatively. A high number of patients had been involved in occupations involving heavy lifting. MRI had a 100% sensitivity in identifying elastofibroma when correlated with histopathological evaluation.

This series demonstrates that elastofibroma may be reliably diagnosed using MRI alone and, in the symptomatic patient, pain and function may be improved through operative excision.

Primary solitary fibrous tumour (SFT) of bone is extremely rare with few cases reported in the literature. The incidence of the lesion is 0.08% of all primary bone tumours (0.1% of primary malignant bone neoplasms). Previously, such lesions may have been reported as haemangiopericytoma (HP).

Despite being previously considered as separate entities, the two types of tumour (SFT and HP) are now generally accepted as related, sharing similar morphological and immunohistochemical features. Cytogenetic and molecular analysis has, so far, been unable to unite or divide the two. Although frequently having a histologically benign appearance or being labelled as intermediate grade, these tumours may exhibit an unpredictable clinical course and behave in an aggressive manner. We present two cases of osseous solitary fibrous tumour (cellular haemangiopericytoma).

Using the histopathology and bone tumour databases at our institution, we identified two patients (one female aged 21 and one male aged 40) with a histopathological diagnosis of osseous SFT. The site of primary tumour in both patients was the sacrum. In the female patient, the lesion was confined to the sacrum and she underwent curettage. In the male patient, the tumour extended beyond the sacrum to the sacro-iliac joint, ilium and gluteal mass, therefore, total sacrectomy was performed. At presentation neither patient had evidence of metastatic spread.

The female patient was disease free at four years with no evidence of recurrence of metastases. The male patient developed metastases in both lung fields and bone (ribs, vertebrae) three years post-operatively and died four years post-operatively.

Orthopaedic surgeons and histopathologists should remain aware of SFT due to its erratic behaviour and the recent move towards unifying it with HP in a continuous spectrum. We recommend early staging and treatment of these tumours, even for histologically benign/low grade lesions, due to their potentially aggressive behaviour.

The proximal tibia is the second most common site for primary bone tumours. As a result of simultaneous advances in chemotherapy, surgical and biomechanical techniques limb salvage is now a practical option. We report the clinical and functional outcomes of eight patients who underwent limb salvage with a new form of endoprosthetic proximal tibial replacement that allows preservation of the knee joint.

A retrospective, case series of 8 patients who underwent joint sparing proximal tibial replacement between 2004 and 2008. There were 2 males and 6 females with a mean age of 28.9 years (8–43) with overall mean follow up of 35 months (4–48). Functional outcomes were assessed using the Musculoskeletal Tumour Society (MSTS) rating score and revised Oxford Knee Score (OKS)

Five patients had osteosarcoma, one patient had malignant fibrous histiocytoma, another adamantinoma and the final patient had Ewing’s sarcoma. All patients had complete tumour excision, neoadjuvant chemotherapy and to date there have been no distant metastasis. One patient however required a below knee amputation through the prosthesis due to local recurrence at the distal bone/prosthesis interface. Another patient fell at postop day 8 and fractured through the tibial metaphyseal bone requiring ORIF; this healed in extension and ultimately required revision to a proximal tibial replacement 20 months later. Mean MSTS and OKS for the remaining 6 patients were 77% (57–90) and 40 (36–46) respectively.

Limb salvage preserving the knee joint is an effective alternative to a proximal tibial replacement when the metaphyseal bone is tumour free. The joint sparing prosthesis has a favourable functional result when compared to the joint sacrificing prostheses. Retaining the native joint improves functional outcomes and reduces the peak loads through the prosthesis. There was no short-term evidence of loosening. Further follow up is required to ascertain the long-term outcomes of this new prosthesis.

Introduction: Metal-on-metal arthroplasties are being used for their increased durability and reduced requirement for revision. Previous data reports that metal-on-metal bearing surfaces release three times more cobolt and chromium ions than metal-on-polyethelene hip replacements. Data also suggests that these metal ions can cause DNA damage.

Method: A prospective study of patients (aged 60–80), meeting exclusion criteria were selected and randomised to metal-on-metal or metal-on-polyethylene articulation. Patients were reviewed preoperatively (control model) and at 3 months, 6 months and one year postoperatively. On each occasion blood tests were taken to quantify metal ion levels (chromium, cobalt, nickel, vanadium and titanium) and chromosome aberrations in T lymphocytes using 24 colour fluorescent in situ hybridization (FISH).

Results: The number of chromosome aberrations increased with time; in particular there was a statistically significant increase in aneuploidy after one year, there was also an increase in chromosome translocations. There was a similar increase in blood concentration of metal ions over this same time period which proved significant. Higher levels of metal ions were seen in the metal-on-metal group when compared with the metal-on-polyethylene.

Conclusion: This study has highlighted the effects of metal ions on chromosome replication in particular causing aneuploidy aberrations. This provides evidence of the short-term effects of metal-on-metal arthroplasty but further research needs to be undertaken to assess long-term risk and also the risk associated to other cell lines.

Introduction: Seeding of bone or soft tissue tumour along the biopsy tract is a known complication of percutaneous biopsies. Correct surgical management requires preoperative Identification and excision of the biopsy tract at time of surgery. We aim to audit how well biopsy tract sites can be identified preoperatively and investigate factors influencing their Identification.

Method: Prospective audit of patients who had tissue biopsies for bone and soft tissue tumours at the RNOH Stanmore and presented for surgery between February and April 2008. Case note analysis, patient history and examination at the time of surgery used to collect data.

Results: 13/23 patients had their biopsy tract site accurately identified preoperatively, with a mean time gap of 43 days (6–118) between biopsy and excision. In 10/23 patients the biopsy site could not be accurately identified preoperatively. In these patients the mean time between biopsy and excision was 106 days (55–158) (p=< 0.05). 7 patients had neoadjuvant chemotherapy with a mean time gap of 110 days; in 5/7 the tract site was unidentifiable. One patient had preoperative radiotherapy and the biopsy site was unidentifiable.

Discussion: This audit has shown that Identification of the biopsy site is more difficult after 40 days. In order to ensure accurate Identification of the biopsy site an Indian ink tattoo should be considered at time of biopsy. It may be particularly advisable for patients who are likely to require neoadjuvant chemotherapy or preoperative radiotherapy.

On this basis we would recommend that all patients have the biopsy site marked at the time of biopsy and a further audit will be carried out to evaluate this change in practice.

Introduction: Total femoral endoprosthetic replacement can be used as an alternative to hip disarticulation following extensive tumour excision or in cases of more severe bone loss. To date there have been no long term studies on the oncological and functional outcome of patients who have had this procedure for malignant bone disease. We report our experience of over 25 years employing this procedure using a custom-made and modular total femoral endoprosthetic replacement.

Methods: This is a retrospective, single centre study of 27 patients who underwent consecutive total femoral replacement as a primary procedure between 1978 and 2005. Information was collected from the bone tumour database, medical records and clinic review. Outcome was assessed using the Musculoskeletal Tumour Society (MSTS) rating score, the Harris Hip Score (HHS) and the Oxford Knee Score (OKS).

Results: There were 15 males and 12 females, with a mean age of 30 years (5 to 65). The overall mean follow-up was 4.3 years (1 to 16.4) for all patients, 9.1 years (1 to 16.4) for the 7 patients who were alive at the time of this review, and 2.6 years (1 to 13) for the 20 patients who had died. 24 patients had primary malignant bone tumours of the femur and 3 had metastatic disease from a known primary elsewhere. 3 patients developed local recurrence, 1 patient developed new lung metastases. Mean MSTS score was 63% (19/30), mean HHS was 68/100 and mean OKS was 34/48.

Discussion: Total femoral replacement can be an effective alternative to hip disarticulation in patients with malignant bone disease. Good functional outcomes can be achieved without compromising survival.