Computer-assisted surgical techniques in knee replacement procedures have been shown to increase the accuracy of implant positioning and reduce the incidence of alignment and soft-tissue balancing “outliers”. The use of this technology as a training tool is less widely reported. However, the recent implementation of the EWTD 48-hour working week for junior doctors has focussed attention on the issues of surgical training and experience. Recent evidence from trainee logbooks has shown a significant downward trend in operative exposure and this is forcing changes in the principles of how training should be delivered. Trainees are actively required to demonstrate operative competence in order to progress but are increasingly faced with limited opportunities to acquire these skills. On the other hand, trainers also face difficulties with the prospect of supervising less accomplished trainees which raises ethical issues of patient protection. We present a trainee’s perspective of experience gained in a unit routinely using computer-assisted technology and highlight the potential to enhance the learning process. Navigation systems provide constant visual and numerical feedback via a computer simulated interpretation. Initially this displays relevant functional anatomy, helps in the identification of anatomical landmarks and demonstrates sagittal and coronal plane deformities which can be difficult to accurately assess “by eye”. Computer-assisted systems have the benefit of displaying only bony anatomy which improves visualisation. This can then be compared to the palpable, clinical deformity on the table. The geometry of the native knee is also made clear with the navigation system leading to a better understand of the objectives of TKR. There are some aspects of the biomechanics of the knee which are difficult to appreciate, such as the changes in varus-valgus alignment during flexion and extension. This may be very subtle and difficult to pick up manually but can look quite dramatic on the computer. The position of cutting jigs which are held to the bone by pins can be altered by inadvertently lifting or hanging on them with the saw, when making the bone cuts. Additionally the cut can be altered by advancing the cutting block closer to the bone, for example if cutting the tibia with a posterior slope. Both these effects can be quantified by using the navigation tools to confirm the cut that has been made. Trainers can have the benefit of seeing the alignment and confirming the cuts made by a trainee without having to get closely involved with the operation. Cementation technique is also open to scrutiny with the ability to compare pre and post cementation alignment. The positive feedback obtained from computer assisted surgery is educational to the trainee, by giving an undisputable computer generated graphic of what they are doing during the different stages of total knee arthroplasty. It also shows what has been achieved at the end of the procedure. This can give both the trainer and trainee more confidence in the procedure and ensures patient safety.
This prospective study assessed the effect of social deprivation on the Oxford hip score at one year after total hip replacement. An analysis of 1312 patients undergoing 1359 primary total hip replacements for symptomatic osteoarthritis was performed over a 35-month period. Social deprivation was assessed using the Carstairs index. Those patients who were most deprived underwent surgery at an earlier age (p = 0.04), had more comorbidities (p = 0.02), increased severity of symptoms at presentation (p = 0.001), and were not as satisfied with their outcome (p = 0.03) compared with more affluent patients. There was a significant improvement in Oxford scores at 12 months relative to pre-operative scores for all socioeconomic categories (p <
0.001). Social deprivation was a significant independent predictor of mean improvement in Oxford scores at 12 months, after adjusting for confounding variables (p = 0.001). Deprivation was also associated with an increased risk of dislocation (odds ratio 5.3, p <
0.001) and mortality at 90 days (odds ratio 3.2, p = 0.02). Outcome, risk of dislocation and early mortality after a total hip replacement are affected by the socioeconomic status of the patient
Infection following hip arthroplasty although uncommon can have devastating outcomes. Obesity, defined as a BMI of ≥ 30, is a risk factor for infection in this population. Coagulase negative staphylococcus aureus (CNS) is the commonest causative organism isolated from infected arthroplasties. This study was performed to determine if there has been a change in the causative organisms isolated from infected hip arthroplasties and to see if there is a difference in obese patients. Data on all deep infection following primary and revision hips was obtained from the surgical site infection register from April 1998 to Nov 2007. Case notes were reviewed retrospectively. There were 49 patients with 51 infected arthroplasties; 25 infected Primary THAs and 26 infected Revision THAs. We found a female preponderance in the infected primary and revision THAs (n=30). 63.2% of all patients had a BMI of ≥ 30, compared to only 34.7% of the non infected population (p<
0.0001). Over the period studied, CNS was the most common organism isolated (56.8%) followed by mixed organisms (37.2%) and staphylococcus aureus (25.4%). Multiple organisms were found exclusively in obese patients. In more than half of cases the causative organisms were resistant to more than two antibiotics. This study shows that over the last 10 years, CNS continues to be the most frequently isolated organism in infected hip arthroplasties. Multiple organisms with multiple antibiotic resistances are common in obese patients. On this basis we recommend that combination antibiotic therapy should be considered in obese patients.
Up to 20% of patients are not satisfied with the outcome following total knee replacement (TKR). This study investigated the pre- and post-operative predictors of dissatisfaction in a large cohort of patients undergoing TKR. We assessed 1217 consecutive patients between 2006 and 2008 both before operation and six months after, using the Short-form (SF)-12 health questionnaire and the Oxford Knee Score. Detailed information concerning comorbidity was also gathered. Satisfaction was measured at one year when 18.6% (226 of 1217) of patients were unsure or dissatisfied with their replacement and 81.4% (911 of 1217) were satisfied or very satisfied. Multivariate regression analysis was performed to identify independent predictors of dissatisfaction. Significant (p <
0.001) predictors at one year included the pre-operative SF-12 mental component score, depression and pain in other joints, the six-month SF-12 score and poorer improvement in the pain element of the Oxford Knee Score. Patient expectations were highly correlated with satisfaction. Satisfaction following TKR is multifactorial. Managing the expectations and mental health of the patients may reduce dissatisfaction. However, the most significant predictor of dissatisfaction is a painful total knee replacement.
We compared the outcome of arthroscopic repair of the rotator cuff in 32 diabetic patients with the outcome in 32 non-diabetic patients matched for age, gender, size of tear and comorbidities. The Constant-Murley score improved from a mean of 49.2 (24 to 80) pre-operatively to 60.8 (34 to 95) post-operatively (p = 0.0006) in the diabetic patients, and from 46.4 (23 to 90) pre-operatively to 65.2 (25 to 100) post-operatively (p = 0.0003) in the non-diabetic patients at six months. This was significantly greater (p = 0.0002) in non-diabetic patients (18.8) than in diabetics (11.6). There was no significant change in the mean mental component of the Short-Form 12, but the mean physical component increased from 35 to 41 in non-diabetics (p = 0.0001), and from 37 to 39 (p = 0.15) in diabetics. These trends were observed at one year. Patients with diabetes showed improvement of pain and function following arthroscopic rotator cuff repair in the short term, but less than their non-diabetic counterparts.
Lumps of the foot present relatively infrequently to the orthopaedic service. There have been very few published studies looking at presenting characteristics or the differential diagnosis of such lesions. We report our experience of foot lumps treated surgically looking at the patient demographics, presenting characteristics, diagnoses encountered and the diagnostic accuracy of the surgeon. All patients who underwent excision or biopsy of a foot lump over a period of 4 years were studied; 101 patients were identified. Average age was 47.3 years (range 14–79); there was a significant female preponderance with 73 females and 28 males (p<
0.0001). Pain was the single most common presenting complaint followed by footwear problems. Only three patients attended because of cosmetic reasons and neurological symptoms were very rare with only one patient complaining of paraesthesia. Certain lesions were more commonly encountered in specific zones of the foot. 32 different histological types were identified, ganglion cysts were the most commonly encountered lesions and there was only one malignant lesion encountered in this study. Only 58 out of the l01 lumps were correctly diagnosed prior to surgery. We have shown that there are a wide variety of potential diagnoses, which have to be considered when examining a patient with a foot lump. There is a low diagnostic accuracy for foot lumps and therefore surgical excision and histological diagnosis should be sought if there is any uncertainty.
Despite the increase in numbers of the extreme elderly, little data is available regarding their outcome after surgery for fracture of the hip. We performed a prospective study of 50 patients aged 95 years and over who underwent this procedure. Outcome measures included morbidity, mortality, hospital stay, residential and walking status. Comparison was made with a control group of 200 consecutive patients aged less than 95 years who had a similar operation. The mortality at 28 and 120 days was higher (p = 0.005, p = 0.001) in the patients over 95 years. However, the one-year cumulative post-operative mortality was neither significantly different between the two groups (p = 0.229) nor from the standardised mortality rate for the age-matched population (p = 0.445). Predictors of mortality included the ASA grade, the number of comorbid medical conditions and active medical problems on admission. Patients over 95 were unlikely to recover their independence and at a mean follow-up of 29.3 months (12.1 to 48) 96% required permanent institutional care.
In-vitro evidence suggests that wear debris can alter osteoblast function resulting in decreased bone matrix production and negative remodelling balance. FRZB encodes for Secreted Frizzled-Related Protein 3 which may play a role in bone formation and osteoarthritis. This study was undertaken to investigate whether the recently described single nucleotide polymorphisms (SNPs) at positions [+6] and [+109] of the FRZB gene are associated with osteolysis after THA. Genomic DNA was extracted from 481 North European Caucasians at a mean of 12 years following cemented THA for idiopathic osteoarthritis. The control group consisted of 267 subjects and the osteolysis group 214 subjects. The [+6] and [+109] FRZB SNPs were genotyped using standard techniques. For the FRZB [+6] SNP, the rare T allele was significantly over-represented in control versus the osteolysis group (χ2 test for trend, p=0.02,). The odds ratio for osteolysis associated with carriage of the [+6] T-allele versus the [+6] C-allele was 0.58 (95%CI 0.36 to 0.94), p=0.03. The odds ratio for osteolysis associated with carriage of the [+109] G-allele versus the [+109] C-allele was 0.66 (0.38 to 1.12), p=0.15. A number of covariates have previously been described in this cohort and after adjustment for the effects of these covariates, the odds ratio for osteolysis with carriage of the [+6] T-allele was 0.69 (0.42–1.16). We found that the FRZB [+6] T-allele is less common in subjects with osteolysis after THA versus controls, suggesting that allelic variants of genes associated with bone formation pathways may have a role in modulating the risk of osteolysis. However its loss of significance after correction for other factors suggests an interaction between this allele and other risk factors in osteolysis.
We performed a prospective audit to assess radiological and clinical sequelae of using injectable calcium sulphate in the management of distal radial fractures. All patients in a 4-month period who were treated with injectable calcium sulphate for distal radial fracture were included in the audit. Initial data was collected on demographics; AO classification and degree of deformity; method of fixation and surgical complications. Follow up consisted of clinical and radiological assessment of fracture healing at standard fracture clinic intervals with a final assessment of subjective functional recovery. 16 patients were included in the audit, all of whom were followed up for a minimum of 8 weeks. We observed a low incidence of secondary displacement, and did not observe the problem of increased pain and erythema that has been observed with other bone graft substitutes. We conclude that injectable calcium sulphate is a useful adjunct to conventional management of these fractures that is safe, helps maintain fracture reduction and is not associated with product specific complications.
The purpose of this study was to investigate the validity of exchange intramedullary nailing for the treatment of infected tibial non-union. 14 (10 male) patients with tibial fractures were treated in our institution with exchange nailing for infected tibial non-union. The mean age of the patients was 34.3 years (range 18–60) and the mean ISS was 17.5 (range 9–57). Seven fractures were originally open (grade IIIb). All patients had clinical and radiological evidence of non-union and in each case there was clinical and microbiological evidence of intramedullary infection. Following initial stabilisation, all the patients subsequently had an exchange intramedullary nail performed together with debridement and antibiotics. The mean time between original nailing and exchange nailing was 28 weeks. Antibiotics were then continued for a minimal period of 6 weeks, or longer as the clinical situation warranted. The average length of follow-up was 24 months following exchange nailing. There were 7 positive cultures of MRSA, 4 of staph. aureus and in 3 cases multiple bacteria were grown from the samples. No further treatment was required following exchange nailing in 5/14 (35.7%) cases. 4 patients required further soft tissue debridement and a free flap to secure union. Of the remaining 5 patients, 1 required dynamisation, another required incision and drainage of peri-fracture abscess, the third patient needed iliac crest bone grafting which eventually resulted in union. The penultimate patient had numerous operations after the exchange nailing before finally uniting with bone morphogenic protein. Unfortunately the last patient developed overwhelming sepsis which necessitated below knee amputation. Overall, the mean time to union was 11.3 months (4–24). In this series of patients the success rate of exchange nailing for septic tibial pseudarthrosis was 78.5% (11/14). We believe that exchange tibial nailing remains an effective method of treatment in the presence of deep bone sepsis.
We assessed patellofemoral joint function by combining the measurement of maximal isometric extensor torque at the knee with clinical and radiological measurements in order to calculate the patellofemoral contact force. Eighteen volunteers established the normal ranges of results and the reliability of the system. Of the 39 patients with a variety of knee problems, 29 had anterior knee pain, and all had a subsequent arthroscopy. Patients with anterior knee pain and lesions in the patellar cartilage had significantly reduced isometric contact forces, but those with normal patellofemoral cartilage had normal contact forces. Our method may be useful in providing an objective assessment of anterior knee pain and a quantitative means of monitoring its treatment.
The use of an osteocutaneous free fibular graft as a single-stage reconstructive procedure for composite tissue loss is increasingly common. Detailed anatomical study in cadavers of the blood supply to the graft demonstrates cutaneous arteries arising from the peroneal artery and then passing along the posterior surface of the lateral intermuscular septum. These vessels pierce the crural fascia and then ramify to supply the skin. Knowledge of the vascular anatomy of the skin overlying the fibula is essential to the success of the graft.