Perioperative mortality in New Zealand related to hip and knee replacement surgery: comparing administrative and registry data.

INTRODUCTION: Perioperative mortality is of considerable importance, but few national assessments are available. New Zealand has a clinical registry and an administrative dataset that both capture national information about hip and knee arthroplasties. National perioperative mortality rates were compared between the two data sources. METHOD: Data related to all patients undergoing an elective hip or knee replacement procedure (primary or revision) between 1 January 2007 and 31 December 2011 were separately extracted from the New Zealand Joint Registry and the National Minimum Dataset. The procedure date was used to define the occurrence of an event and dates were compared between datasets plus or minus 3 days. Date of death information was obtained from the National Mortality Collection and used to estimate 30 day mortality rates. RESULTS: No statistically significant differences in perioperative mortality were evident between comparisons from the two data sources although more deaths were recorded among Registry-only procedures. CONCLUSIONS: Estimates of 30 day perioperative mortality related to hip and knee arthroplasty procedures in New Zealand 2007-2011 are very similar regardless of data source. These data, coupled with perioperative mortality review using structured reports obtained from clinicians, could be used to develop a surveillance system to promote surgical safety.

Femoral nerve infusion after primary total knee arthroplasty: a prospective, double-blind, randomised and placebo-controlled trial.

OBJECTIVES: Effective analgesia after total knee arthroplasty (TKA) improves patient satisfaction, mobility and expedites discharge. This study assessed whether continuous femoral nerve infusion (CFNI) was superior to a single-shot femoral nerve block in primary TKA surgery completed under subarachnoid blockade including morphine. METHODS: We performed an adequately powered, prospective, randomised, placebo-controlled trial comparing CFNI of 0.125% bupivacaine versus normal saline following a single-shot femoral nerve block and subarachnoid anaesthesia with intrathecal morphine for primary TKA. Patients were randomised to either treatment (CFNI 0 ml to 10 ml/h 0.125% bupivacaine) or placebo (CFNI 0 ml to 10 ml/h normal saline). Both groups received a single-shot femoral nerve block (0.25% 20 ml bupivacaine) prior to placement of femoral nerve catheter and subarachnoid anaesthesia with intrathecal morphine. All patients had a standardised analgesic protocol. The primary end point was post-operative visual analogue scale (VAS) pain score over 72 hours post-surgery. Secondary outcomes were morphine equivalent dose, range of movement, side effects, and length of stay. RESULTS: A total of 86 patients were recruited. Treatment and placebo groups were comparable. No significant difference was found in VAS pain scores, total morphine equivalent requirements, side effects, range of movement, motor block, or length of hospital stay. CONCLUSION: No significant advantage was found for CFNI over a single-shot femoral block and subarachnoid anaesthesia after TKA. Cite this article: Bone Joint Res 2015;4:11-16.

Gunshot induced indirect femoral fracture: mechanism of injury and fracture morphology.

INTRODUCTION: Indirect ballistic fractures occur when a projectile passes close to, but not contacting, the bone. The mechanism of how these fractures occur is not yet proven, but recently the acoustic shockwave has been excluded as a cause. The objective of this study is to determine whether the expanding temporary cavity, the collapse of this cavity or its oscillation causes these fractures. In addition, we describe the fracture morphology and biomechanical causes of this injury. METHOD: 40 fresh deer femora were strain gauged and embedded in ballistic gelatin before being shot with four different projectiles with varying distances off the bone. Pressure recordings, chronographs and radar allowed assessment of local pressures and energy transfer. High-speed video allowed the temporal relationship between the temporary cavity and fracture formation to be analysed, while sample dissection allowed the fracture morphology to be described. RESULTS: The fractures produced were consistently wedge-shaped and caused by the expansion of the temporary cavity, flexing the bone beyond its yield point, causing tension failure on the cortex opposite the expanding temporary cavity and a compression wedge on the side of the cavity. Local pressure was not predictive of fracture formation but the energy transfer to the gelatin block was predictive. CONCLUSIONS: Indirect fractures are caused by the expansion of the temporary cavity and relate to the proximity of this cavity to the bone. Fractures occur from flexion of the bone and classically display wedge-shaped fracture patterns with the apex of the wedge pointing away from the expanding cavity.

Identifying the source of bullet wipe: a randomised blind trial.

OBJECTIVE: To assess the usefulness of scanning electron microscopy and energy dispersive x-ray spectroscopy in matching bullet wipe to the bullet. HYPOTHESIS: Bullet wipe can be used to match a bullet type to a crime scene.

Manual therapy, exercise therapy, or both, in addition to usual care, for osteoarthritis of the hip or knee: a randomized controlled trial. 1: clinical effectiveness.

OBJECTIVE: To evaluate the clinical effectiveness of manual physiotherapy and/or exercise physiotherapy in addition to usual care for patients with osteoarthritis (OA) of the hip or knee. DESIGN: In this 2 × 2 factorial randomized controlled trial, 206 adults (mean age 66 years) who met the American College of Rheumatology criteria for hip or knee OA were randomly allocated to receive manual physiotherapy (n = 54), multi-modal exercise physiotherapy (n = 51), combined exercise and manual physiotherapy (n = 50), or no trial physiotherapy (n = 51). The primary outcome was change in the Western Ontario and McMaster osteoarthritis index (WOMAC) after 1 year. Secondary outcomes included physical performance tests. Outcome assessors were blinded to group allocation. RESULTS: Of 206 participants recruited, 193 (93.2%) were retained at follow-up. Mean (SD) baseline WOMAC score was 100.8 (53.8) on a scale of 0-240. Intention to treat analysis showed adjusted reductions in WOMAC scores at 1 year compared with the usual care group of 28.5 (95% confidence interval (CI) 9.2-47.8) for usual care plus manual therapy, 16.4 (-3.2 to 35.9) for usual care plus exercise therapy, and 14.5 (-5.2 to 34.1) for usual care plus combined exercise therapy and manual therapy. There was an antagonistic interaction between exercise therapy and manual therapy (P = 0.027). Physical performance test outcomes favoured the exercise therapy group. CONCLUSIONS: Manual physiotherapy provided benefits over usual care, that were sustained to 1 year. Exercise physiotherapy also provided physical performance benefits over usual care. There was no added benefit from a combination of the two therapies. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry ACTRN12608000130369.

Variability of blood lactate during and between given constant prolonged cycling power.

AIM: Blood lactate concentration (BLC) has been the basis of rational performance diagnostics for almost five decades. Aim of this study was to identify the variability of the BLC during repeated constant power tests (VC-BLC) and to quantify the corresponding variability of changes in the BLC over time (VC-BLC-Difference). METHODS: Twelve healthy male subjects (24.8±3-8 years, 182.9±7.5 cm, 75.7±7.1 kg, ·VO2peak: 4.1±0.6 l min-1) performed four series of three constant power tests at exercise intensities of 45% (A), 60% (B), 75% (C) and 90% (D) of VO2peak. Blood sampling was conducted before, at the end of every 5th min and at the end of each test terminated ahead of schedule. RESULTS: BLC was different at all exercise intensities from minute five onwards. Power output was equivalent to 142.1±18.9 W (A), 196.3±25.2 W (B), 247.9±30.3 W (C) and 302.5±38.4 W (D). VC-BLC varied between 9±2.2% and 21±10.1%. VC-BLC and VC-BLC-Difference between 10th and 30th min correlated inversely with mean BLC level and BLC-Difference respectively. CONCLUSION: By providing first data on constant power test VC-BLC and VC-BLC-Difference this study might help to improve performance diagnostics and training control in sports medicine and medical exercise therapy by assisting in selecting and monitoring exercise intensity. Performance monitoring with BLC-Differences is feasible at moderate and high exercise intensities; single BLC measurements at termination of tests might not be sufficient.

Age at hip or knee joint replacement surgery predicts likelihood of revision surgery.

We compared revision and mortality rates of 4668 patients undergoing primary total hip and knee replacement between 1989 and 2007 at a University Hospital in New Zealand. The mean age at the time of surgery was 69 years (16 to 100). A total of 1175 patients (25%) had died at follow-up at a mean of ten years post-operatively. The mean age of those who died within ten years of surgery was 74.4 years (29 to 97) at time of surgery. No change in comorbidity score or age of the patients receiving joint replacement was noted during the study period. No association of revision or death could be proven with higher comorbidity scoring, grade of surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery have a greater chance of requiring a revision than of dying, those around 58 years of age have a 50:50 chance of needing a revision, and in those older than 62 years the prosthesis will normally outlast the patient. Patients over 77 years old have a greater than 90% chance of dying than requiring a revision whereas those around 47 years are on average twice as likely to require a revision than die. This information can be used to rationalise the need for long-term surveillance and during the informed consent process.

Predicting the transition from acute to persistent low back pain.

BACKGROUND: Most people experience low back pain (LBP) at least once in their lifetime. Only a minority of them go on to develop persistent LBP. However, the socioeconomic costs of persistent LBP significantly exceed the costs of the initial acute LBP episode. AIMS: To identify factors that influence the progression of acute LBP to the persistent state at an early stage. METHODS: Prospective inception cohort study of patients attending a health practitioner for their first episode of acute LBP or recurrent LBP after a pain free period of at least 6 months. Patients were assessed at baseline addressing occupational and psychological factors as well as pain, disability, quality of life and physical activity and followed up at 3, 6, 12 weeks and 6 months. Variables were combined to the three indices 'working condition', 'depression and maladaptive cognitions' and 'pain and quality of life'. RESULTS: The index 'depression and maladaptive cognitions' was found to be a significant baseline predictor for persistent LBP up to 6 months (OR 5.1; 95% CI: 1.04-25.1). Overall predictive accuracy of the model was 81%. CONCLUSIONS: In this study of patients with acute LBP in a primary care setting psychological factors at baseline correlated with a progression to persistent LBP up to 6 months. The benefit of including factors such as 'depression and maladaptive cognition' in screening tools is that these factors can be addressed in primary and secondary prevention.

Identification of prognostic factors for chronicity in patients with low back pain: a review of screening instruments.

Low back pain (LBP) is currently the most prevalent and costly musculoskeletal problem in modern societies. Screening instruments for the identification of prognostic factors in LBP may help to identify patients with an unfavourable outcome. In this systematic review screening instruments published between 1970 and 2007 were identified by a literature search. Nine different instruments were analysed and their different items grouped into ten structures. Finally, the predictive effectiveness of these structures was examined for the dependent variables including "work status", "functional limitation", and "pain". The strongest predictors for "work status" were psychosocial and occupational structures, whereas for "functional limitation" and "pain" psychological structures were dominating. Psychological and occupational factors show a high reliability for the prognosis of patients with LBP. Screening instruments for the identification of prognostic factors in patients with LBP should include these factors as a minimum core set.

Implant retention in infected joint replacements: a surgeon's perspective.

There is no standard treatment for infected joint replacements. The surgical options are varied and treatment choices may pose problems in relation to both efficacy and cost effectiveness. Surgical debridement combined with antibiotic therapy is an appealing option for surgeons and patients as it can lead to eradication of the infection with implant retention and good functional outcome. It avoids major revision surgery which can result in significant morbidity and mortality in an elderly group of patients.The author reviewed 73 patients with hip and knee periprosthetic infections and the data was analyzed in terms of outcome of primary treatment and final outcome, including bacteriology and prosthesis retention. Out of the 73 patients (53 hips and 20 knees), the majority (69%) were managed by primary surgical debridement followed by antibiotics and about one third (34%) lost their implants as a result of the infection. Retention of implants was higher in acute infections (85-100%) as opposed to late infections (20-50%). The microbiological analysis showed that Staphylococcus and Streptococcus caused the majority (76%) of infections. In this series, patients with an infected joint replacement had roughly the same probability (30%) of retaining the original prosthesis, undergoing a successful revision, or having no implants in situ at the end of treatment.

Long-term follow-up of a recurrent multifocal desmoid tumour treated with tamoxifen: a case report.

We report a long-term follow-up of a female patient with a multifocal extremity desmoid tumour. She had 3 local recurrences after excision and developed a second unresectable pelvic tumour that has remained unchanged in size for 14 years since starting tamoxifen treatment.

Rehabilitation after surgery for flexor tendon injuries in the hand.

BACKGROUND: Postoperative rehabilitation of the flexor tendons in the hand consists of a short period of immobilisation while pain and swelling diminish, followed by progressive mobilisation to maximize the range of motion of the affected fingers. By altering the time of immobilisation and the manner of subsequent mobilisation different rehabilitation regimes are created. OBJECTIVES: To determine, with evidence from randomised controlled trials, the optimal rehabilitation strategy after surgery for flexor tendon injuries in the hand. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group specialised register (November 2002), the Cochrane Central Register of Controlled Trials (The Cochrane Library, issue 4, 2002), MEDLINE (1966 to November 2002), EMBASE (1988 to November 2002), CINAHL (1982 to October 2002), CURRENT CONTENTS (1993 to October 2002), PEDro - The Physiotherapy Evidence Database (http://ptwww.cchs.usyd.edu.au/pedro/ accessed 30/10/2002) and reference lists of articles. SELECTION CRITERIA: All randomised and quasi-randomised controlled trials of interventions for rehabilitation after surgery of flexor tendon injuries in the hand after surgery. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality, using a 10 item scale, and extracted data where possible. Additional information was sought from trialists when required. Due to the lack of extractable data and the variety of interventions used, pooling was not attempted. Where possible relative risks and 95 per cent confidence intervals were calculated for dichotomous outcomes, and mean differences and 95 per cent confidence intervals calculated for continuous outcomes. MAIN RESULTS: Six trials, including three reported only in abstracts, with a total of 464 participants were included. Data were not pooled. One trial compared continuous passive motion (CPM) with controlled intermittent passive motion (CIPM) and found a significant difference in mean active motion favouring CPM (WMD 19.00 degrees, 95% CI 15.11 to 22.89). One trial compared a shortened passive flexion/active extension programme with a normal passive flexion/active extension mobilisation programme, and reported (without data) a significant reduction in absence from work of 2.1 weeks in favour of the shortened programme. Other trials compared active flexion with rubber band traction, early controlled active mobilisation with early controlled passive mobilisation and dynamic splintage versus static splintage. No trials found significant differences in overall functioning or complication rate. REVIEWERS' CONCLUSIONS: Controlled mobilisation regimens are widely employed in rehabilitation after flexor tendon repair in the hand. This review found insufficient evidence from randomised controlled trials to define the best mobilisation strategy.

Clinical priority criteria in orthopaedics: a validation study using the SF36 quality of life questionnaire.

This study reports a validation trial of a clinical priority scoring tool in orthopaedic surgery based on five dimensions related to need and ability to benefit using the SF36 health related quality of life questionnaire. Seventy patients attending an orthopaedic outpatient clinic were asked to complete the questionnaire before being seen by an orthopaedic specialist. Their clinical priority for surgery was scored using a tool which assesses five dimensions of clinical need with a maximum of 100 points. Our study has shown that the clinical priority scores correlate very well with the quality of life of patients and that those who were selected for surgery had a significantly worse quality of life compared to those not qualifying for surgery due to the lack of financial resources. Although this study has limits, it should provide sufficient information to healthcare clinicians and managers that this tool will select those patients who have the highest need and ability to benefit from surgery.

Medium-term results of cementless hydroxyapatite-coated primary total hip arthroplasty: a clinical and radiological review.

PURPOSE: To evaluate the clinical and radiological outcomes following cementless primary hydroxyapatite-coated total hip arthroplasty. METHODS: A retrospective study of 69 patients (82 hips) who underwent uncemented hydroxyapatite-coated Anatomic Benoist Girard total hip replacement between October 1991 and October 1995 at our institution was conducted. Patient records were reviewed. All patients were evaluated clinically using the Merle D'Aubigne hip score, and osteointegration was assessed radiographically by analysing the bone implant interface in the 7 zones of Gruen on followup review. RESULTS: The mean follow-up period was 7.3 years. Clinical results were excellent with an improvement seen in clinical score from 9.9 preoperatively to 16.5 at last review. A total of 15% of patients recorded some thigh discomfort, which was intermittent and not functionally limiting, except in 2 cases. There were 3 cases of severe acetabular osteolysis and loosening requiring revision surgery, and 4 cases of localised proximal femoral osteolysis around well-ingrown implants. There were few perioperative complications, with the exception of 5 dislocations of which 3 were recurrent and required a revision procedure. CONCLUSION: Clinical and radiological outcomes following cementless hydroxyapatite-coated total hip arthroplasty were seen to be favourable in this medium-term retrospective study.

Changes in proximal femoral bone mineral density around a hydroxyapatite-coated hip joint arthroplasty.

OBJECTIVE: To present the results of a prospective analysis of proximal femoral bone mineral density changes around a hydroxyapatite-coated total hip joint replacement. METHODS: 14 patients with osteoarthritis of the hip were enrolled in the study and treated with an uncemented ABG prosthesis. Dual energy X-ray absorptiometry scanning was performed in 9 patients preoperatively, and at 3, 6, 12, and 24 months postoperatively. An orthopaedic software program was used to determine the bone mineral density in the proximal femur, expressed as a percentage of the preoperative value. RESULTS: The values of Gruen zones 1 to 6 averaged between 96.0% and 113.8% of the preoperative value by 24 months (overall average, 104.1%). In zone 7, however, there was a gradual decline in bone mineral density to an average of 72.1% of the preoperative value by 24 months. This represented ongoing loss of bone from the calcar; although this may not pose a problem to the prosthetic's short-term stability, it may render potential revision surgery more difficult. CONCLUSION: The initial outcome of uncemented total hip replacement appears to be promising. There was excellent maintenance of bone around the femoral component in all regions other than the calcar and lesser trochanter. Further scans are required to see if these trends continue in the long term.

Degradation of hydroxyapatite coating on a well-functioning femoral component.

We carried out a histological study of a proximally hydroxyapatite (HA)-coated femoral component, retrieved after 9.5 years of good function. The HA coating had completely degraded. Bone was in direct contact with the titanium surface in all the areas which had been coated, with no interposing fibrous tissue. There were no signs of particles, third-body wear, adverse tissue reactions or osteolysis. Bone remodelling was evident by the presence of resorption lacunae; tetracycline labelling showed bone laid down six years after implantation. The loss of the HA-coating had no negative effect on the osseo-integration of the stem. We conclude that the HA coating contributes to the fixation of the implant and that its degradation does not adversely affect the long-term fixation.

Severe necrotising soft tissue infections in orthopaedic surgery.

PURPOSE: To review all cases of necrotising infection managed in the Department of Orthopaedic Surgery of Dunedin Hospital in New Zealand between 1989 and 1998. METHODS: Hospital records were analysed for predisposing factors, clinical features, diagnostic results, treatment strategies, and outcomes. RESULTS: 13 cases (9 males and 4 females) of necrotising infection were identified. The mean age was 48 years (range, 8-76 years). Presenting symptoms included painful swelling, erythema, and necrosis. Most patients had predisposing factors and had received nonsteroidal anti-inflammatory drugs before presentation. 12 patients underwent surgical debridement including a total of 4 amputations. Septic shock developed in 9 patients who required dialysis for renal failure. Four patients died. The most common organisms identified were group A beta-haemolytic streptococci. CONCLUSION: Severe necrotising infections require a high index of suspicion and rapid medical and surgical intervention to reduce the mortality and morbidity.

Mycobacterium xenopi infection of the spine: a case report and literature review.

STUDY DESIGN: A case report of Mycobacterium xenopi. OBJECTIVES: To present a case report of a vertebral osteomyelitis caused by M. xenopi and to review the world literature on the subject. SUMMARY OF BACKGROUND DATA: M. xenopi is most commonly a pulmonary pathogen in immunosuppressed patients or those with underlying lung disease. Infection of the spine is very rare, with only four cases reported. Three of these cases occurred in immunosuppressed patients, and the fourth in a patient with previous tuberculosis osteomyelitis of the spine. METHODS: The information was obtained from a review of the patient's clinical notes and follow-up appointments. RESULTS: The patient was a 73-year-old woman with an M. xenopi osteomyelitis of T6-T7, confirmed by magnetic resonance imaging and a computed tomography-guided biopsy. She was treated with surgical decompression and stabilization before a 2-year antibiotic regimen was begun. At follow-up assessment 1 year after the antibiotics were finished, she still had some ongoing back pain, but no evidence of relapse. CONCLUSIONS: This is the first reported case of an M. xenopi infection of the spine in a patient with no predisposing factors. This type of infection can be difficult to treat, with a high relapse rate reported despite prolonged courses of antibiotics.

Acute compartment syndrome due to closed muscle rupture.

Acute compartment syndrome has multiple causes: fractures, crush injury, vascular trauma and burns. Exertional compartment syndrome may be acute (progressive) or chronic (usually reversible). The acute form usually occurs after intensive exercise. Closed muscle rupture is an uncommon cause with few reports. We report two cases, in the peroneal compartment of the leg and the flexor compartment of the forearm, to show that a high index of suspicion, allowing prompt diagnosis and fasciotomy, will enable a full recovery without complications.