The long term biological effects of wear products following total hip arthroplasty (THA) are unclear. However, the indications for THA are expanding, with increasingly younger patients undergoing the procedure.

This prospective, randomised study compared two groups of patients undergoing THA after being randomised to receive one of two different bearing surfaces: metal-on-polyethylene (MoP) n = 22 and metal-on-metal (MoM) n = 23. We investigated the relationship between three variables: bearing surface (MoP vs MoM), whole blood levels of chromium (Cr) and cobalt (Co) and chromosomal aberrations in peripheral lymphocyte pre-operatively and at one, two and five years post-surgery.

Our results demonstrated significantly higher mean cobalt and chromium (Co and Cr) blood levels in the MoM group at all follow-up points following surgery (p < 0.01), but there were no significant differences in the chromosomal aberration indices between MoM and MoP at two or five years (two years: p = 0.56, p = 0.08, p = 0.91, p = 0.51 and five years: p = 0.086, p = 0.73, p = 0.06, p = 0.34) for translocations, breaks, loss and gain of chromosomes respectively. Regression analysis showed a strong linear relationship between Cr levels and the total chromosomal aberration indices in the MoM group (R² = 0.90016), but this was not as strong for Co (R² = 0.68991). In the MoP group, the analysis revealed a poor relationship between Cr levels and the total chromosomal aberration indices (R² = 0.23908) but a slightly stronger relationship for Co (R² = 0.64292). Across both groups, Spearman’s correlation detected no overall association between Co and Cr levels and each of the studied chromosomal aberrations. There remains no clear indication which THA bearing couple is the most biocompatible, especially in young active patients. While THA continues to be very successful at alleviating pain and restoring function, the long-term biological implications of the procedure still require further scrutiny.

Cite this article: Bone Joint J 2015;97-B:1183–91.

The pre-operative differentiation between enchondroma, low-grade chondrosarcoma and high-grade chondrosarcoma remains a diagnostic challenge. We reviewed the accuracy and safety of the radiological grading of cartilaginous tumours through the assessment of, first, pre-operative radiological and post-operative histological agreement, and second the rate of recurrence in lesions confirmed as high-grade on histology. We performed a retrospective review of major long bone cartilaginous tumours managed by curettage as low grade between 2001 and 2012. A total of 53 patients with a mean age of 47.6 years (8 to 71) were included. There were 23 men and 30 women. The tumours involved the femur (n = 20), humerus (n = 18), tibia (n = 9), fibula (n = 3), radius (n = 2) and ulna (n = 1). Pre-operative diagnoses resulted from multidisciplinary consensus following radiological review alone for 35 tumours, or with the addition of pre-operative image guided needle biopsy for 18. The histologically confirmed diagnosis was enchondroma for two (3.7%), low-grade chondrosarcoma for 49 (92.6%) and high-grade chondrosarcoma for two (3.7%). Three patients with a low-grade tumour developed a local recurrence at a mean of 15 months (12 to 17) post-operatively. A single high-grade recurrence (grade II) was treated with tibial diaphyseal replacement. The overall recurrence rate was 7.5% at a mean follow-up of 4.7 years (1.2 to 12.3). Cartilaginous tumours identified as low-grade on pre-operative imaging with or without additional image-guided needle biopsy can safely be managed as low-grade without pre-operative histological diagnosis. A few tumours may demonstrate high-grade features histologically, but the rates of recurrence are not affected.

Cite this article: Bone Joint J 2014; 96-B:1098–105.

We reviewed the outcome of 69 uncemented, custom-made, distal femoral endoprosthetic replacements performed in 69 patients between 1994 and 2006. There were 31 women and 38 men with a mean age at implantation of 16.5 years (5 to 37). All procedures were performed for primary malignant bone tumours of the distal femur. At a mean follow-up of 124.2 months (4 to 212), 53 patients were alive, with one patient lost to follow-up. All nine implants (13.0%) were revised due to aseptic loosening at a mean of 52 months (8 to 91); three implants (4.3%) were revised due to fracture of the shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic fracture. Bone remodelling associated with periosteal cortical thinning adjacent to the uncemented intramedullary stem was seen in 24 patients but this did not predispose to failure. All aseptically loose implants in this series were diagnosed to be loose within the first five years.

The results from this study suggest that custom-made uncemented distal femur replacements have a higher rate of aseptic loosening compared to published results for this design when used with cemented fixation. Loosening of uncemented replacements occurs early indicating that initial fixation of the implant is crucial.

Cite this article: Bone Joint J 2014;96-B:263–9.

Matrix-induced autologous chondrocyte implantation (MACI) is an established technique used to treat osteochondral lesions in the knee. For larger osteochondral lesions (> 5 cm²) deeper than approximately 8 mm we have combined the use of two MACI membranes with impaction grafting of the subchondral bone. We report our results of 14 patients who underwent the ‘bilayer collagen membrane’ technique (BCMT) with a mean follow-up of 5.2 years (2 to 8). There were 12 men and two women with a mean age of 23.6 years (16 to 40). The mean size of the defect was 7.2 cm² (5.2 to 12 cm²) and were located on the medial (ten) or lateral (four) femoral condyles. The mean modified Cincinnati knee score improved from 45.1 (22 to 70) pre-operatively to 82.8 (34 to 98) at the most recent review (p < 0.05). The visual analogue pain score improved from 7.3 (4 to 10) to 1.7 (0 to 6) (p < 0.05). Twelve patients were considered to have a good or excellent clinical outcome. One graft failed at six years.

The BCMT resulted in excellent functional results and durable repair of large and deep osteochondral lesions without a high incidence of graft-related complications.

In skeletally immature patients, resection of bone tumours and reconstruction of the lower limb often results in leg-length discrepancy. The Stanmore non-invasive extendible endoprosthesis, which uses electromagnetic induction, allows post-operative lengthening without anaesthesia. Between 2002 and 2009, 55 children with a mean age of 11.4 years (5 to 16) underwent reconstruction with this prosthesis; ten patients (18.2%) died of disseminated disease and one child underwent amputation due to infection. We reviewed 44 patients after a mean follow-up of 41.2 months (22 to 104). The mean Musculoskeletal Tumor Society score was 24.7 (8 to 30) and the Toronto Extremity Salvage score was 92.3% (55.2% to 99.0%). There was no local recurrence of tumour. Complications developed in 16 patients (29.1%) and ten (18.2%) underwent revision.

The mean length gained per patient was 38.6 mm (3.5 to 161.5), requiring a mean of 11.3 extensions (1 to 40), and ten component exchanges were performed in nine patients (16.4%) after attaining the maximum lengthening capacity of the implant. There were 11 patients (20%) who were skeletally mature at follow-up, ten of whom had equal leg lengths and nine had a full range of movement of the hip and knee.

This is the largest reported series using non-invasive extendible endoprostheses after excision of primary bone tumours in skeletally immature patients. The technique produces a good functional outcome, with prevention of limb-length discrepancy at skeletal maturity.

Patients with skeletal dysplasia are prone to developing advanced osteoarthritis of the knee requiring total knee replacement (TKR) at a younger age than the general population. TKR in this unique group of patients is a technically demanding procedure owing to the deformity, flexion contracture, generalised hypotonia and ligamentous laxity. We retrospectively reviewed the outcome of 11 TKRs performed in eight patients with skeletal dysplasia at our institution using the Stanmore Modular Individualised Lower Extremity System (SMILES) custom-made rotating-hinge TKR. There were three men and five women with mean age of 57 years (41 to 79). Patients were followed clinically and radiologically for a mean of seven years (3 to 11.5). The mean Knee Society clinical and function scores improved from 24 (14 to 36) and 20 (5 to 40) pre-operatively, respectively, to 68 (28 to 80) and 50 (22 to 74), respectively, at final follow-up. Four complications were recorded, including a patellar fracture following a fall, a tibial peri-prosthetic fracture, persistent anterior knee pain, and aseptic loosening of a femoral component requiring revision. Our results demonstrate that custom primary rotating-hinge TKR in patients with skeletal dysplasia is effective at relieving pain, with a satisfactory range of movement and improved function. It compensates for bony deformity and ligament deficiency and reduces the likelihood of corrective osteotomy. Patellofemoral joint complications are frequent and functional outcome is worse than with primary TKR in the general population.

The best method of reconstruction after resection of malignant tumours of the tibial diaphysis is unknown. In the absence of any long-term studies analysing the results of intercalary endoprosthetic replacement, we present a retrospective review of 18 patients who underwent limb salvage using a tibial diaphyseal endoprosthetic replacement following excision of a malignant bone tumour. There were ten men and eight women with a mean age of 42.5 years (16 to 76). Mean follow-up was 58.5 months (20 to 141) for all patients and 69.3 months (20 to 141) for the 12 patients still alive. Cumulative patient survival was 59% (95% confidence interval (CI) 32 to 84) at five years. Implant survival was 63% (95% CI 35 to 90) at ten years. Four patients required revision to a proximal tibial replacement at a mean follow-up of 29 months (10 to 54). Complications included metastases in five patients, aseptic loosening in four, peri-prosthetic fracture in two, infection in one and local recurrence in one. The mean Musculoskeletal Tumor Society score and the mean Toronto Extremity Salvage Score were 23 (17 to 28) and 74% (53 to 91), respectively.

Although rates of complication and revision were high, custom-made tibial diaphyseal replacement following resection of malignant bone tumours enables early return to function and provides an attractive alternative to other surgical options, without apparent compromise of patient survival.

We describe 22 cases of bizarre parosteal osteochondromatous proliferation, or Nora’s lesion. These are surface-based osteocartilaginous lesions typically affecting the hands and feet. All patients were identified from the records of a regional bone tumour unit and were treated between 1985 and 2009. Nine lesions involved the metacarpals, seven the metatarsals, one originated from a sesamoid bone of the foot and five from long bones (radius, ulna, tibia, and femur in two). The mean age of the patients was 31.8 years (6 to 66), with 14 men and eight women. Diagnosis was based on the radiological and histological features. The initial surgical treatment was excision in 21 cases and amputation of a toe in one. The mean follow-up was for 32 months (12 to 162). Recurrence occurred in six patients (27.3%), with a mean time to recurrence of 49 months (10 to 120). Two of the eight patients with complete resection margins developed a recurrence (25.0%), compared with four of 14 with a marginal or incomplete resection (28.6%).

Given the potential surgical morbidity inherent in resection, our data suggest that there may be a role for a relatively tissue-conserving approach to the excision of these lesions.

Introduction: Non-invasive expandable prostheses for limb salvage tumour surgery was first used in 2002 and has now been implanted in a series of 40 skeletally immature patients.

Method: Our review of these includes 24 distal femoral replacements, 5 proximal femoral replacements, 3 total femoral replacements and 8 proximal tibial replacements. These were used to treat 31 osteosarcomas, 7 Ewing’s sarcomas, 1 chondrosarcoma and 1 aneurysmal bone cyst. Patients had a mean age of 11.7 years (7–16). Follow-up extended to 88 months with a mean of 26.3 months.

Results: There has been 1 failure of the prosthesis gearbox which required revision surgery. 4 of the prostheses reached their maximum length and were successfully re-operated to exchange components of the prosthesis and resume lengthening. 3 patients had disseminated meta-static disease (1 being present before primary surgery) and another developed infection of the prosthesis that required an above-knee amputation. There have been 233 lengthenings overall with 1 patient requiring reversal on one occasion due to intractable pain; this pain rescinded 30 minutes after lengthening was reduced by 10mm. Otherwise lengthening was well tolerated despite the significant growth of the limbs: mean 21.2mm (0.5–84mm). At latest follow-up the mean Musculoskeletal Tumour Society score was 75% (26–93%).

Discussion: The results achieved are equivalent to our series of minimally invasive growers which require repeated surgery. Our non-invasive growing prostheses remain reliable and negate the need for recurrent operations, thus resulting in low infection rates. Our results remain encouraging up to 7 years after first use, maintaining leg-length equality and function.

Introduction: Intramedullary cementless fixation of massive tumor prostheses was developed to combat the high incidence of aseptic loosening in a young population of tumor patients. Its use has also expanded to include reconstruction of failed major knee arthroplasty. Our system uses a hydroxyapatite coated titanium stem in conjunction with a hydroxyapatite collar to obtain fixation.

Methods: We present a series of 72 patients (34 females, 38 males) with a mean follow-up of six years (2 months – 14 years). The mean age at the time of surgery was 17 (5 – 77). Within this group, 51 patients had osteosarcomas, 10 had giant cell tumors, eight had Ewing’s sarcoma and one each had malignant fibrous histiocytoma, spindle cell sarcoma and failed total knee arthroplasty. Non-invasive and minimally invasive growing prostheses were used in 33 patients.

Results: Nine patients required revision of the prosthesis at a mean of 5.2 years; 5 for aseptic loosening and four for infection. Twelve patients died at a mean of 20 months (1 – 84) post-operatively. Radiological evidence demonstrated remodelling around both the stem and the collar. There was gap closure to the hydroxyapatite coated collar in cases where seating was not complete. Consistent loss of cortical bone around the mid-stem was noted in the first 12 months but remained stable beyond this time frame.

Discussion: This study highlights our experience with cementless distal femoral endosprostheses. We demonstrate good results with regard to revision rate, gap closure and osseointegration.

Introduction: Alveolar soft part sarcoma (ASPS) is a soft tissue tumour found primarily in adolescents and young adults. It has an incidence of 0.5 – 1.0 % of all soft tissue sarcomas and a predilection for females. The lesion is inherently malignant and may occur throughout the body however, reports suggest they are predominantly detected in the anterior thigh. Symptoms include a painless slow-growing mass but ASPS can commonly present with brain or lung metastases due to the high vascularity of the lesion. Microscopically, cellular groups exist with centralised areas of necrosis, thus resulting in a pseudoalveolar appearance.

Methods: We identified six cases of histologically proven ASPS. The mean age was 28.5 years (21–36). Four patients were male. All patients had a primary presentation of a mass, two of which were painful. All patients, except one, presented within 8 months of the onset of symptoms (mean 3.8 months) with the other seeking medical advice only after 72 months. The location of the mass included the thigh in three patients and the triceps, soleus and retroperitoneal space in the others. Four patients underwent pre-operative diagnostic biopsies. Surgical excision was performed in all patients.

Results: The mean size of tumour was 9.4 x 9.4 x 6.3cm but there was no correlation between lesion size and duration of symptoms. The patient who presented late was found to have multiple lung metastases prior to surgery. Despite appropriate adjuvant therapy, three patients developed post-operative metastases at a mean of 5.2 months (1–24), two of which died along with the patient who presented with metastases at a mean of 2.6 years.

Discussion: This series demonstrates that this tumour may present as a painful mass. Despite early detection and appropriate treatment, ASPS remains a highly malignant neoplasm with a high associated mortality rate.

We have reviewed five adult patients treated with endoprosthetic reconstruction of the proximal radius following resection of non-traumatic lesions. The patients had a mean age of 33.4 years (20 to 60) at the time of surgery and the mean follow-up was 7.6 years (0.8 to 16).

Following surgery, all elbows were clinically stable and there was 100% survivorship of the prosthesis. Evaluation of function was assessed clinically and by the Mayo Elbow Performance Score, achieving a mean of 86% (70 to 100).

Results at medium-term follow-up are encouraging with regards to elbow stability, implant survivorship and functional outcome.

Segmental resection of malignant bone disease in the femoral diaphysis with subsequent limb reconstruction is a major undertaking. This is a retrospective review of 23 patients who had undergone limb salvage by endoprosthetic replacement of the femoral diaphysis for a primary bone tumour between 1989 and 2005.

There were 16 males and seven females, with a mean age of 41.3 years (10 to 68). The mean overall follow-up was for 97 months (3 to 240), and 120 months (42 to 240) for the living patients. The cumulative patient survival was 77% (95% confidence interval 63% to 95%) at ten years. Survival of the implant, with failure of the endoprosthesis as an endpoint, was 85% at five years and 68% (95% confidence interval 42% to 92%) at ten years. The revision rate was 22% and the overall rate of re-operation was 26%. Complications included deep infection (4%), breakage of the prosthesis (8%), periprosthetic fracture (4%), aseptic loosening (4%), local recurrence (4%) and metastases (17%). The 16 patients who retained their diaphyseal endoprosthesis had a mean Musculoskeletal Tumour Society score of 87% (67% to 93%). They were all able to comfortably perform most activities of daily living.

Femoral diaphyseal endoprosthetic replacement is a viable option for reconstruction following segmental resection of malignant bone disease. It allows immediate weight-bearing, is associated with a good long-term functional outcome, has an acceptable complication and revision rate and, most importantly, does not appear to compromise patient survival.

Elastofibroma dorsi is an uncommon, benign, slow-growing soft-tissue tumour of uncertain aetiology. It classically presents as an ill-defined mass at the inferior pole of the scapula with symptoms which include swelling, discomfort, snapping, stiffness and occasionally pain.

We report the symptoms, function and outcome after treatment of 21 elastofibromas in 15 patients. All were diagnosed by MRI and early in the series four also underwent CT-guided biopsy to confirm the diagnosis. In all, 18 tumours were excised and three were observed. After excision, the mean visual analogue score for pain decreased from 4.6 (0 to 10) pre-operatively to 2.4 (0 to 8) post-operatively (p = 0.04). The mean shoulder function, at a mean follow-up of 4.2 years (3 months to 16 years), was 78.1% (30 to 100) using the Stanmore percentage of normal shoulder assessment scoring system. The mean range of forward flexion improved from 135° (70° to 180°) to 166° (100° to 180°) after excision (p = 0.005). In four patients a post-operative haematoma formed; one required evacuation. Three patients developed a post-operative seroma requiring needle aspiration and one developed a superficial infection which was treated with antibiotics.

Our findings support previous reports suggesting that a pre-operative tissue diagnosis is not necessary in most cases since the lesion can be confidently diagnosed by MRI, when interpreted in the light of appropriate clinical findings. Surgical excision in symptomatic patients, is helpful.

It has been suggested that elastofibroma is caused by a local tissue reaction and is not a true neoplastic process. A strong association has been noted between elastofibroma and repetitive use of the shoulder, which is supported by our findings.

Dedifferentiated chordoma is a rare and aggressive variant of the conventional tumour in which an area undergoes transformation to a high-grade lesion, typically fibrous histiocytoma, fibrosarcoma, and rarely, osteosarcoma or rhabdomyosarcoma. The dedifferentiated component dictates overall survival, with smaller areas of dedifferentiation carrying a more favourable prognosis. Although it is more commonly diagnosed in recurrences and following radiotherapy, there have been a few reports of spontaneous development. We describe four such cases, which were diagnosed de novo following primary excision, and discuss the associated clinical and radiological features.

Free, vascularised fibular grafting is well described in limb salvage surgery. The mechanical properties of the fibula make it ideal for replacement of bony defects after tumour resection and it can be sacrificed with minimal morbidity. We review the outcome of a consecutive series of 24 patients.

Between 1993 and 2002 we performed free vascularised fibular grafts in 24 patients as part of a limb salvage procedure following tumour excision. Pre-operatively patients were staged using the Musculoskeletal Tumour Society (MSTS) system. Post-operatively patients were followed up with radiographs and clinical examination. From the radiographs graft hypertrophy and time to bony union was documented. Functional outcome was assessed using the MSTS scoring system. Complications were recorded.

There were 15 women and 9 men with a mean age of 26 years (6–52). Mean follow up was 51 months (12–106). There were 19 malignant tumours, all stage 2b, and 5 giant cell tumours. The mean length of graft was 12.5 cm. (4.5–25). 16 grafts were used in the upper limb and 8 in the lower limb. Arthrodesis was performed in 8 cases and intercalary reconstruction in 16 cases. Fixation of grafts was achieved with a plate and screws in 21, a blade plate in 2 and an IM nail in 1. In 6 cases the resected tumour bone was reinserted as autograft after extracorporeal irradiation. In all but one patient the tumour margins were clear. Primary bony union was achieved in 22 patients (92%) at a mean of 35 weeks (12–78). Graft hypertrophy was seen in 7/29 cases (24%). Complications included 2 wound breakdowns, 3 stress fractures, 1 muscle contracture, 1 malunion and 1 painful plate. Overall 8 patients (33%) required second operation. 2 patients died of recurrent disease and one has metastases. The mean MSTS functional score was 87% (80–93).

Free vascularised fibula grafts offer a reliable method of reconstruction after excision of bone tumours. The complication rate appears high and some patients require a revision procedure. However, the problems are relatively easy to correct, bony union is achieved in the majority and functional outcome is good.