Introduction

We investigated predictors of poor outcomes following metal-on-metal hip arthroplasty (MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD), to help inform the revision threshold and type of reconstruction.

Aim

To assess the survival of revision knee replacements at our institution and to identify prognostic factors that predict failure in revision knee surgery.

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.

Introduction: The Oxford hip score (OHS) instrument is used to assess pain and disability before and after hip arthroplasty and may be used as a standard for auditing pre and post-operative patients. It has been suggested that patients with a low pre-operative hip score (< 25th percentile) should be carefully assessed before surgical management is employed. This study aimed to determine the factors that influence a surgeon’s decision to undertake hip arthroplasty in patients with a low pre-operative hip score.

Methods: All patients who underwent hip arthroplasty over a two month period (n=121) were included. Of these, four pre-operative OHS questionnaires were missing. The remaining (117) were validated and those scoring below the published 25th percentile (58.3%) were selected (n=35), termed the ‘low-group’. Individual OHS responses scored 0–4 were examined (0 = no impairment and 4 = worst impairment) and the proportional differences between the responses for this group and the remaining 75% were investigated. The pre-operative radiographic Tönnis stage of osteoarthritis was determined.

Results: The median cohort OHS was 68.8% (IQR = 50–79%). Of the questions that scored highly, 59% were purely pain related, 14% function and 27% both. 66% of patients experienced moderate/severe pain and 31% suffered night pain. The ‘low-group’ never scored 4 (worst impairment) on questions concerning washing, transport, shopping, stairs and work. However, 57% scored 4 on questions encompassing a pain component. In all questions except donning socks and walking, the proportion of 4 in the ‘low-group’ was significantly different to the remainder of the cohort. Tönnis grade 3 (osteophytes and advanced loss of joint space) osteoarthritis predominated (49%).

Conclusion: Arthroplasty in patients with low pre-operative OHS is influenced mainly by pain affecting quality of life. Half of these patients also have advanced features of osteoarthritis on radiographic assessment despite the low scores.

Introduction: The correct identification of the infecting micro-organism in prosthetic joint infections is difficult and there is no single method that is wholly reliable. We report a novel method intended to improve accuracy by disrupting the biofilm surrounding the prosthesis and transferring samples rapidly to culture medium.

Method: Explanted prostheses from 20 revision operations were sampled by pressing a microbiology swab or by passing a No.10 surgical blade along it. The sample so obtained was plated immediately in the operating theatre onto horse-agar petri dishes. These were incubated in aerobic conditions in the laboratory. Culture results were compared with those obtained from our standard detection method using multiple tissue samples with are plated or grown in prolonged aerobic and anaerobic culture broth.

Results: The method proved practical to perform in practice. When compared with multiple tissue samples as the standard, the Positive Predictive Value was 90%, Negative Predictive Value 80%, sensitivity 82%, specificity 89%. In 4 of the 10 true positive samples, the theatre-inoculated samples yielded early results within 3 days, while conventional method yielded positives only later on prolonged culture.

Discussion: The above pilot is to continue and has started to alter our practice in sample taking. Blade-scrape does appear to penetrate the biofilm successfully. Growing confidence in interpretation and ease in reading the plates mean that in certain cases, we consider the results to be more reliable than traditional tissue culture. Direct plating also reduces the chance of bacterial overgrowth in broth inhibiting colonies of secondary infective organisms. Further refinement is needed, particularly with regard to anaerobic bacteria. Inaccuracies have resulted when agar plates are allowed to go out of date.

Purpose: The aim of this study was to understand the effect of endoprosthetic reconstruction in treatment of solitary bone plasmacytoma threatening structural integrity of bone.

Materials and methods: We retrospectively studied 11 patients who underwent endoprosthetic reconstruction for solitary bone plasmacytoma between 1988 and 2003 with more than 1 year follow up. Most had radiotherapy and those who sustained structural damage to a joint or thought to be salvageable were treated with endoprosthetic replacement.

Results: There were 7 males and 4 females, with M: F ratio of 1.75:1, the median age at diagnosis was 53.61years (35–74). Average duration of symptoms prior to presentation at oncology unit was 7.27 months. We had 4 proximal femoral, 2 pelvic, 4 humeral and one tibial Plasmacytomas that were treated with endoprosthetic replacements.8/11 had preoperative radiotherapy for at least 4weeks and 3 did not. Two had postoperative radiotherapy and one adjuvant chemotherapy. Average follow up is 5.45 years (range 1–16years). We had one death due to unrelated causes, one progression to Myeloma treated with adjuvant chemotherapy, two revisions and one dislocation which was reduced by open method. The cumulative overall survival for all patients was 91% at 5 years. The cumulative risk of failure of reconstruction including; infection, dislocation, local recurrence/progression to Myeloma was 27% at 5 years.

Conclusion: Literature review shows that nearly 53% of SBP progress despite radiotherapy to Myeloma at a median time of 1.8 years (2–4 years). But despite average follow up of 5.45 years, progression to Myeloma after endoprosthetic replacement at our unit is 9.09%. We concluded that the use of endoprostheses for reconstruction after excision of solitary bone plasmacytomas threatening structural integrity of bone combined with radiotherapy decreases the disease progression to Myeloma than radiotherapy alone and offers a reasonable but not absolute chance of cure.

Objective To assess the validity of Somatosensory Evoked Potential (SSEP) monitoring in identifying potential spinal cord vascular damage resulting from segmental artery ligation in anterior spinal deformity correction.

Design SSEP monitoring was undertaken in patients deemed at risk of spinal cord vascular injury during corrective surgery. The segmental vessels of the vertebral bodies to be instrumented were identified. Baseline SSEPs were obtained prior to application of non-crushing microvascular clamps. After ten minutes of occlusion, further SSEP recordings were made. Surgery proceeded with either, vessel ligation and division allowing anterior instrumentation, or vessel sparing anterior release.

Subjects 22 patients were included; 7 had Scheuermann’s hyperkyphosis and 15 had scoliosis (11 idiopathic, 3 syndromic, 1 neuromuscular). Perceived risk was defined by the presence of hyperkyphosis, abnormal neurological examination or radiologically identified spinal cord anomaly.

Outcome Measures A drop of 30% from baseline reading was taken as significant. Post-operative neurological outcome was correlated with intra-operative signal change and alteration in planned surgery.

Results There was no significant drop in post-clamping SSEPs in the hyperkyphotic patients. In 3 scoliosis patients anterior instrumentation was abandoned and a release was performed. Staged posterior instrumentation followed. In a further 2, anterior instrumentation proceeded but in a modified fashion. The remaining 10 patients had no significant drop and underwent the surgery as planned. No patient sustained a neurological injury.

Conclusions SSEP monitoring is safe in assessing the apparent contribution of segmental vessel blood supply to the spinal cord in spinal deformity surgery. It has allowed timely alteration of planned surgical procedures that potentially may have caused vascular spinal cord injury.