Bone loss in the proximal tibia and distal femur is frequently encountered in revision knee replacement surgery. The various options for dealing with this depend on the extent of any bone loss. We present our results with the use of cementless metaphyseal metal sleeves in 103 patients (104 knees) with a mean follow-up of 43 months (30 to 65). At final follow-up, sleeves in 102 knees had good osseointegration. Two tibial sleeves were revised for loosening, possibly due to infection.

The average pre-operative Oxford Knee Score was 23 (11 to 36) and this improved to 32 (15 to 46) post-operatively. These early results encourage us to continue with the technique and monitor the outcomes in the long term.

Cite this article: Bone Joint J 2013;95-B:1640–4.

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution.

We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients.

Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control.

The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Cite this article: Bone Joint J 2015;97-B:258–64.

The treatment of infected nonunions is difficult. Antibiotic cement-coated (ACC) rods provide stability as well as delivering antibiotics. We conducted a review of 110 infected nonunions treated with ACC rods. Patients were divided into two groups: group A (67 patients) with an infected arthrodesis, and group B (43 patients) with an infected nonunion in a long bone. In group A, infected arthrodesis, the success rate after the first procedure was 38/67 (57%), 29/67 (43%) required further surgery for either control of infection or non-union. At last follow-up, five patients required amputation, representing a limb salvage rate of 62/67 (93%) overall. In all, 29/67 (43%) presented with a bone defect with a mean size of 6.78 cm (2 to 25). Of those with a bone defect, 13/29 (45%) required further surgery and had a mean size of defect of 7.2 cm (3.5 to 25). The cultures were negative in 17/67 (26%) and the most common organism cultured was methicillin-resistant staphylococcus aureus (MRSA) (23/67, (35%)). In group B, long bones nonunion, the success rate after the first procedure was 26/43 (60%), 17/43 (40%) required further surgery for either control of infection or nonunion. The limb salvage rate at last follow-up was 43/43 (100%). A total of 22/43 (51%) had bone defect with a mean size of 4.7 cm (1.5 to 11.5). Of those patients with a bone defect, 93% required further surgery with a mean size of defect of 5.4 cm (3 to 8.5). The cultures were negative in 10/43 (24%) and the most common organism cultured was MRSA, 15/43 (35%). ACC rods are an effective form of treatment for an infected nonunion, with an acceptable rate of complications.

Cite this article: Bone Joint J 2014; 96-B:1349–54

Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR.

The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time.

This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.

We report a 12- to 15-year implant survival assessment of a prospective single-surgeon series of Birmingham Hip Resurfacings (BHRs). The earliest 1000 consecutive BHRs including 288 women (335 hips) and 598 men (665 hips) of all ages and diagnoses with no exclusions were prospectively followed-up with postal questionnaires, of whom the first 402 BHRs (350 patients) also had clinical and radiological review.

Mean follow-up was 13.7 years (12.3 to 15.3). In total, 59 patients (68 hips) died 0.7 to 12.6 years following surgery from unrelated causes. There were 38 revisions, 0.1 to 13.9 years (median 8.7) following operation, including 17 femoral failures (1.7%) and seven each of infections, soft-tissue reactions and other causes. With revision for any reason as the end-point Kaplan–Meier survival analysis showed 97.4% (95% confidence interval (CI) 96.9 to 97.9) and 95.8% (95% CI 95.1 to 96.5) survival at ten and 15 years, respectively. Radiological assessment showed 11 (3.5%) femoral and 13 (4.1%) acetabular radiolucencies which were not deemed failures and one radiological femoral failure (0.3%).

Our study shows that the performance of the BHR continues to be good at 12- to 15-year follow-up. Men have better implant survival (98.0%; 95% CI 97.4 to 98.6) at 15 years than women (91.5%; 95% CI 89.8 to 93.2), and women < 60 years (90.5%; 95% CI 88.3 to 92.7) fare worse than others. Hip dysplasia and osteonecrosis are risk factors for failure. Patients under 50 years with osteoarthritis fare best (99.4%; 95% CI 98.8 to 100 survival at 15 years), with no failures in men in this group.

Cite this article: Bone Joint J 2014;96-B:1298–1306.

The August 2012 Oncology Roundup³⁶⁰ looks at: prolonged symptom duration; peri-operative mortality and above-knee amputation; giant cell tumour of the spine; surgical resection for Ewing’s sarcoma; intercalary allograft reconstruction of the femur for tumour defects; and an induced membrane technique for large bone defects.

We investigated whether the extension gap in total knee replacement (TKR) would be changed when the femoral component was inserted. The extension gap was measured with and without the femoral component in place in 80 patients with varus osteoarthritis undergoing posterior-stabilised TKR. The effect of a post-operative increase in the size of the femoral posterior condyles was also evaluated. The results showed that placement of the femoral component significantly reduced the medial and lateral extension gaps by means of 1.0 mm and 0.9 mm, respectively (p < 0.0001). The extension gap was reduced when a larger femoral component was selected relative to the thickness of the resected posterior condyle. When the post-operative posterior lateral condyle was larger than that pre-operatively, 17 of 41 knees (41%) showed a decrease in the extension gap of > 2.0 mm. When a specially made femoral trial component with a posterior condyle enlarged by 4 mm was tested, the medial and lateral extension gaps decreased further by means of 2.1 mm and 2.8 mm, respectively.

If the thickness of the posterior condyle is expected to be larger than that pre-operatively, it should be recognised that the extension gap is likely to be altered. This should be taken into consideration when preparing the extension gap.

We aimed to obtain anthropometric data on Korean knees and to compare these with data on commonly available total knee arthroplasties (TKAs). The dimensions of the femora and tibiae of 1168 knees were measured intra-operatively. The femoral components were found to show a tendency toward mediolateral (ML) under-coverage in small femurs and ML overhang in the large femurs. The ML under-coverage was most prominent for the small prostheses. The ML/anteroposterior (ML/AP) ratio of Korean tibiae was greater than that of tibial components.

This study shows that, for different reasons, current TKAs do not provide a reasonable fit for small or large Korean knees, and that the ‘gender-specific’ and ‘stature-specific’ components help for large Korean femurs but offer less satisfactory fits for small femurs. Specific modifications of prostheses are needed for Asian knees.

Objectives

Because posterior cruciate ligament (PCL) resection makes flexion gaps wider in total knee replacement (TKR), preserving or sacrificing a PCL affects the gap equivalence; however, there are no criteria for the PCL resection that consider gap situations of each knee. This study aims to investigate gap characteristics of knees and to consider the criteria for PCL resection.

We determined the efficacy of a devitalised autograft (n = 13) and allograft (n = 16) cortical strut bone graft combined with long-stem endoprosthetic reconstruction in the treatment of massive tumours of the lower limb. A total of 29 patients (18 men:11 women, mean age 20.1 years (12 to 45) with a ratio of length of resection to that of the whole prosthesis of > 50% were treated between May 2003 and May 2012. The mean follow-up was 47 months (15 to 132). The stem of the prosthesis was introduced through bone graft struts filled with cement, then cemented into the residual bone. Bone healing was achieved in 23 patients (86%). The mean Musculoskeletal Tumour Society functional score was 85% (57 to 97). The five-year survival rate of the endoprostheses was 81% (95% confidence intervals 67.3 to 92.3). The mean length of devitalised autografts and allografts was 8.6 cm (5 to 15), which increased the ratio of the the length of the stem of the prosthesis to that of the whole length of the prosthesis from a theoretical 35% to an actual 55%.

Cortical strut bone grafting and long-stem endoprosthetic reconstruction is an option for treating massive segmental defects following resection of a tumour in the lower limb. Patients can regain good function with a low incidence of aseptic loosening. The strut graft and the residual bone together serve as a satisfactory bony environment for a revision prosthesis, if required, once union is achieved.

Cite this article: Bone Joint J 2015;97-B:544–9.

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.

The December 2013 Oncology Roundup³⁶⁰ looks at: Peri-articular resection fraught with complications; Navigated margins; Skeletal tumours and thromboembolism; Conditional survival in Ewing’s sarcoma; Reverse shoulders and tumour; For how long should we follow up sarcoma patients?; and already metastasised?

We performed a randomised controlled trial comparing computer-assisted surgery (CAS) with conventional surgery (CONV) in total knee replacement (TKR). Between 2009 and 2011 a total of 192 patients with a mean age of 68 years (55 to 85) with osteoarthritis or arthritic disease of the knee were recruited from four Norwegian hospitals. At three months follow-up, functional results were marginally better for the CAS group. Mean differences (MD) in favour of CAS were found for the Knee Society function score (MD: 5.9, 95% confidence interval (CI) 0.3 to 11.4, p = 0.039), the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for ‘pain’ (MD: 7.7, 95% CI 1.7 to 13.6, p = 0.012), ‘sports’ (MD: 13.5, 95% CI 5.6 to 21.4, p = 0.001) and ‘quality of life’ (MD: 7.2, 95% CI 0.1 to 14.3, p = 0.046). At one-year follow-up, differences favouring CAS were found for KOOS ‘sports’ (MD: 11.0, 95% CI 3.0 to 19.0, p = 0.007) and KOOS ‘symptoms’ (MD: 6.7, 95% CI 0.5 to 13.0, p = 0.035). The use of CAS resulted in fewer outliers in frontal alignment (> 3° malalignment), both for the entire TKR (37.9% vs 17.9%, p = 0.042) and for the tibial component separately (28.4% vs 6.3%, p = 0.002). Tibial slope was better achieved with CAS (58.9% vs 26.3%, p < 0.001). Operation time was 20 minutes longer with CAS. In conclusion, functional results were, statistically, marginally in favour of CAS. Also, CAS was more predictable than CONV for mechanical alignment and positioning of the prosthesis. However, the long-term outcomes must be further investigated.

Cite this article: Bone Joint J 2014; 96-B:609–18.

This review is aimed at clinicians appraising preclinical trauma studies and researchers investigating compromised bone healing or novel treatments for fractures. It categorises the clinical scenarios of poor healing of fractures and attempts to match them with the appropriate animal models in the literature.

We performed an extensive literature search of animal models of long bone fracture repair/nonunion and grouped the resulting studies according to the clinical scenario they were attempting to reflect; we then scrutinised them for their reliability and accuracy in reproducing that clinical scenario.

Models for normal fracture repair (primary and secondary), delayed union, nonunion (atrophic and hypertrophic), segmental defects and fractures at risk of impaired healing were identified. Their accuracy in reflecting the clinical scenario ranged greatly and the reliability of reproducing the scenario ranged from 100% to 40%.

It is vital to know the limitations and success of each model when considering its application.

Objectives

We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip.

The April 2013 Oncology Roundup³⁶⁰ looks at: the margin for error; new money for old risks; hindquarter amputation; custom tumour jigs; preserving the tibial epiphysis; how long is long enough?; genomics and radiation-induced bone tumours; and India ink.

The role of modular tibial implants in total knee replacement is not fully defined. We performed a prospective randomised controlled clinical trial using radiostereophotogrammetric analysis to compare the performance of an all-polyethylene tibia with a metal-backed cruciate-retaining condylar design, PFC-∑ total knee replacement for up to 24 months. There were 51 patients who were randomised into two treatment groups. There were 10 subsequent withdrawals, leaving 21 all-polyethylene and 20 metal-backed tibial implants. No patient was lost to follow-up. There were no significant demographic differences between the groups. At two years one metal-backed implant showed migration > 1 mm, but no polyethylene implant reached this level. There was a significant increase in the SF-12 and Oxford knee scores after operation in both groups.

In an uncomplicated primary total knee replacement the all-polyethylene PFC-∑ tibial prosthesis showed no statistical difference in migration from that of the metal-backed counterpart. There was no difference in the clinical results as assessed by the SF-12, the Oxford knee score, alignment or range of movement at 24 months, although these assessment measures were not statistically powered in this study.

The Motec cementless modular metal-on-metal ball-and-socket wrist arthroplasty was implanted in 16 wrists with scaphoid nonunion advanced collapse (SNAC; grades 3 or 4) and 14 wrists with scapholunate advanced collapse (SLAC) in 30 patients (20 men) with severe (grades 3 or 4) post-traumatic osteoarthritis of the wrist. The mean age of the patients was 52 years (31 to 71). All prostheses integrated well radiologically. At a mean follow-up of 3.2 years (1.1 to 6.1) no luxation or implant breakage occurred. Two wrists were converted to an arthrodesis for persistent pain. Loosening occurred in one further wrist at five years post-operatively. The remainder demonstrated close bone–implant contact. The clinical results were good, with markedly decreased Disabilities of the Arm Shoulder and Hand (DASH) and pain scores, and increased movement and grip strength. No patient used analgesics and most had returned to work.

Good short-term function was achieved using this wrist arthroplasty in a high-demand group of patients with post-traumatic osteoarthritis.

We retrospectively reviewed 101 consecutive patients with 114 femoral tumours treated by massive bone allograft at our institution between 1986 and 2005. There were 49 females and 52 males with a mean age of 20 years (4 to 74). At a median follow-up of 9.3 years (2 to 19.8), 36 reconstructions (31.5%) had failed. The allograft itself failed in 27 reconstructions (24%).

Mechanical complications such as delayed union, fracture and failure of fixation were studied. The most adverse factor on the outcome was the use of intramedullary nails, followed by post-operative chemotherapy, resection length > 17 cm and age > 18 years at the time of intervention. The simultaneous use of a vascularised fibular graft to protect the allograft from mechanical complications improved the outcome, but the use of intramedullary cementing was not as successful.

In order to improve the strength of the reconstruction and to advance the biology of host–graft integration, we suggest avoiding the use of intramedullary nails and titanium plates, but instead using stainless steel plates, as these gave better results. The use of a supplementary vascularised fibular graft should be strongly considered in adult patients with resection > 17 cm and in those who require post-operative chemotherapy.

The Bologna–Oxford (BOX) total ankle replacement (TAR) was developed with the aim of achieving satisfactory pain-free movement of the ankle. To date, only one single multicentre study has reported its clinical results. The aim of this study was to conduct an independent review of its mid-term results.

We retrospectively reviewed a total of 60 prospectively followed patients in whom 62 BOX TARs had been implanted between 2004 and 2008. We used the American Orthopedic Foot and Ankle Society (AOFAS) score to assess the clinical results. Standardised radiographs taken at the time of final follow-up were analysed by two observers. The overall survival was 91.9% at a mean follow-up of 42.5 months (24 to 71). The mean AOFAS score had improved from 35.1 points (sd 16.6; 4 to 73) pre-operatively to 78.0 (sd 10.7; 57 to 100) at final follow-up (p < 0.01). Tibial radiolucencies < 2 mm in width were seen around 16 TARs. Talar radiolucencies < 2 mm were seen around four TARs. A total of 47 patients (78.3%) were very satisfied or satisfied with the outcome. Five patients required revision for functional limitation or continuing pain.