Results of 'two-in-one' single-stage revision total knee arthroplasty for infection with associated bone loss : prospective five-year follow up.

AIMS: Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss. METHODS: Patients were identified from prospective data on all TKA patients with PJI following the primary procedure. Inclusion criteria were: revision for PJI with bone loss requiring reconstruction, and a minimum five years' follow-up. Patients were followed up for recurrent infection and assessment of function. Tools used to assess function were Oxford Knee Score (OKS) and American Knee Society Score (AKSS). RESULTS: A total of 24 patients were included with a mean age of 72.7 years (SD 7.6), mean BMI of 33.3 kg/m2 (SD 5.7), and median ASA grade of 2 (interquartile range 2 to 4). Mean time from primary to revision was 3.0 years (10 months to 8.3 years). At revision, six patients had discharging sinus and three patients had negative cultures from tissue samples or aspirates. Two patients developed recurrence of infection: one was treated successfully with antibiotic suppression and one underwent debridement, antibiotics, and implant retention. Mean AKSS scores at two years showed significant improvement from baseline (27.1 (SD 10.2 ) vs 80.3 (SD 14.8); p < 0.001). There was no significant change in mean AKSS scores between two and five years (80.3 (SD 14.8 ) vs 74.1 (SD 19.8); p = 0.109). Five-year OKS scores were not significantly different compared to two-year scores (36.17 (SD 3.7) vs 33.0 (SD 8.5); p = 0.081). CONCLUSION: 'Two-in-one' single-stage revision is effective for treating PJI following TKA with bone loss, providing patients with sustained improvements in outcomes and infection clearance up to five years post-procedure. Cite this article: Bone Jt Open 2022;3(2):107-113.

Comparison of Existing and New Total Knee Arthroplasty Implant Systems From the Same Manufacturer: A Prospective, Multicenter Study.

INTRODUCTION: This study evaluated total knee arthroplasty (TKA) outcomes for an Existing-TKA versus New-TKA from the same manufacturer. METHODS: TKA outcomes for 752 with Existing-TKA versus 1129 subjects with New-TKA were followed through 2 years using patient-reported outcome measures (PROMs). Responders were assessed per Outcome Measures in Rheumatology-Osteoarthritis Research Society International criteria. Kaplan-Meier implant survivorship was estimated. Radiographs had an independent radiographic review. RESULTS: Two-year follow-up was 84.6% (636/752) for Existing-TKA and 82.5% (931/1129) for New-TKA. Two-year PROMs mean outcomes for New-TKA versus Existing-TKA at 2 years were: Knee Injury and Osteoarthritis Outcome Score (ADL: 89.0 versus 86.8, P = 0.005; pain: 88.9 versus 87.1, P = 0.019; symptoms: 84.1 versus 82.2, P = 0.017; Sport/Rec: 63.9 versus 58.8, P = 0.001; and QOL: 77.0 versus 73.5, P = 0.003), Patient's Knee Implant Performance (overall: 76.5 versus 73.5, P = 0.003; confidence: 8.4 versus 8.1, P = 0.004; stability: 8.6 versus 8.3, P = 0.006; satisfaction: 8.3 versus 8.1, P = 0.042; and modifying activities: 6.6 versus 6.4, P = 0.334), Oxford Knee Score (41.9 versus 41.1, P = 0.027), and EQ5D-3L (0.88 versus 0.88, P = 0.737). Two-year responder rates using WOMAC were 93.9% versus 90.6% (P = 0.018) for New-TKA versus Existing-TKA. Independent radiographic review showed that tibial and femoral radiolucencies ≥2 mm were similar (P ≥ 0.05) or favored New-TKA. Implant survivorship was similar between groups (log-rank P = 0.9994). DISCUSSION: New-TKA versus Existing-TKA demonstrated slightly better PROMs with similar radiographic and implant survivorship outcomes.

Results of Using a "2-in-1" Single-Stage Revision Total Knee Arthroplasty for Infection with Associated Bone Loss: Prospective 2-Year Follow-Up.

Prosthetic joint infections provide a complex challenge for management, owing to their often difficult diagnoses, need for multiple surgeries, and increased technical and financial requirements. The '2 in 1' single-stage approaches have been recently advocated in the field of arthroplasty on account of their reduction in risks, costs, and complications. The aim of our study was to investigate the outcomes of this variant of single-stage revision, which is used in the setting of infection following primary total knee replacement (TKR) and associated bone loss. Prospective data were collected from all patients presenting with an infection following primary TKR over an 8-year period (2009-2017). We examined revision procedures that were undertaken as a single-stage procedure and had bone loss present. Patients were followed-up for evidence of recurrent infection. Functional assessments were conducted using range of motion, Oxford Knee Score (OKS), American Knee Society Score (AKSS), and Short Form-12 (SF-12) survey. Twenty-six patients were included in the analysis, two of whom had previously failed 2 stage revision; another three among them had failed debridement, antibiotics, irrigation, and implant retention procedures. The mean age was 72.5 years, mean body mass index was 33.4, and median American Society of Anesthesiologists (ASA) physical status classification was 2. The mean time to revision was 3.5 years (3 months to 12 years). Six patients had actively been discharging sinuses at the time of surgery. Only 4/26 patients possessed no positive microbiological cultures from deep tissue samples or joint aspirates. One patient was afflicted with a recurrence of infection. This patient did not require further surgery and was successfully treated with the help of long-term antibiotic suppression. There were statistically significant improvements in both the pain component of AKSS scores (preoperative 4.3 to postoperative 32.4) and the functional component of AKSS scores (preoperative 10.7 to postoperative 15.7). There was no significant improvement in flexion; however, mean extension (increased from 18.5 to 6.9 postoperative) and total range of motion (increased from 69.2 preoperative to 90.3 postoperative) both showed statistically significant improvements. The use of "2-in-1" single-stage revision can be considered as an effective option for treating infection following TKR and associated bone loss.

Revision total knee arthroplasty versus primary total knee arthroplasty: a matched cohort study.

INTRODUCTION: The primary aim of this study was to describe a baseline comparison of early knee-specific functional outcomes following revision total knee arthroplasty (TKA) using metaphyseal sleeves with a matched cohort of patients undergoing primary TKA. The secondary aim was to compare incidence of complications and length of stay (LOS) between the two groups. METHODS: Patients undergoing revision TKA for all diagnoses between 2009 and 2016 had patient-reported outcome measures (PROMs) collected prospectively. PROMs consisted of the American Knee Society Score (AKSS) and Short-Form 12 (SF-12). The study cohort was identified retrospectively and demographics were collected. The cohort was matched to a control group of patients undergoing primary TKA. RESULTS: Overall, 72 patients underwent revision TKA and were matched with 72 primary TKAs with a mean follow-up of 57 months (standard deviation (SD) 20 months). The only significant difference in postoperative PROMs was a worse AKSS pain score in the revision group (36 vs 44, p = 0.002); however, these patients still produced an improvement in the pain score. There was no significant difference in improvement of AKSS or SF-12 between the two groups. LOS (9.3 days vs 4.6 days) and operation time (1 hour 56 minutes vs 1 hour 7 minutes) were significantly higher in the revision group (p < 0.001). Patients undergoing revision were significantly more likely to require intraoperative lateral release and postoperative urinary catheterisation (p < 0.001). CONCLUSION: This matched-cohort study provides results of revision TKA using modern techniques and implants and outlines what results patients can expect to achieve using primary TKA as a control. This should be useful to clinicians counselling patients for revision TKA.

Ten-Year Results of the Press Fit Condylar Sigma Cobalt-Chrome Total Knee Replacement.

Total knee arthroplasty (TKA) is reliant on safe and effective implants. The Press Fit Condylar Sigma Cobalt-Chrome (PFCSCC) was introduced in 2006, but no reports have examined long-term failure rates and patient-reported outcome measures (PROMs). The primary aim of this study was to assess survival outcomes of the PFCSCC at 10 years after implantation. Prospective data collection was performed on all patients undergoing primary TKA in one orthopaedic department using this prosthesis exclusively from February 1, 2006, to January 31, 2007. Follow-up was at 10 years. Survival analysis was performed using two primary outcome measures: (1) all-cause joint revision and (2) aseptic revision. Secondary outcomes measures included the American Knee Society Score (AKSS) and Oxford Knee Score (OKS). In total, 249 knees of 233 patients underwent primary TKA. Mean patient age was 66.7 years (range 34-80), and mean body mass index (BMI) was 30 kg/m2 (20.7-40.1). Reviewing all causes of revisions, 14 joints (5.6%) of 14 patients required reoperation. Of these, nine were for deep infection, including six in the first year. Four (1.6%) underwent aseptic revision. Mean AKSS changed from 47.6 to 90.4 (n = 140; p < 0.001) at 10 years, and mean OKS changed from 38.3 to 23.2 (n = 149; p < 0.001). Prospective analysis of consecutive TKA cases using this design of prosthesis demonstrated high survival rates of 94.4% (all-cause revision) and 98.4% (aseptic revision) at 10 years. Postoperative gains in PROMs were sustained at 10 years. These real-world data represent a substantial extension to previous reports for the PFCSCC and suggest that it is not prone to late mechanical failure.

Excellent Survival and Good Outcomes at 15 Years Using the Press-Fit Condylar Sigma Total Knee Arthroplasty.

BACKGROUND: We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty. METHODS: Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained. RESULTS: Of our initial cohort, 99 patients (118 knees) were alive at 15 years, and 31 patients (34 knees) were lost to follow-up. Thirteen knees (5.5%) were revised; 5 (2.1%) for infection, 7 (3%) for instability, and 1 (0.4%) for aseptic loosening. Cumulative survival with the end point of revision for any reason was 92.3% at 15 years and with revision for aseptic failure as the end point was 94.4%. The mean Knee Society Score knee score was 77.4 (33-99) at 15 years, compared with 31.7 (2-62) preoperatively. Of 71 surviving knees for which X-rays were available, 12 (16.9%) had radiolucent lines and 1 (1.4%) demonstrated clear radiographic evidence of loosening. CONCLUSION: The Press-Fit Condylar Sigma total knee arthroplasty represents a durable, effective option for patients undergoing knee arthroplasty, with excellent survival and good clinical and radiographic outcomes at 15 years.

Body mass index, hip function and surgeon volume are independent predictors of dislocation: an analysis of 4334 total hip replacements.

The aim of this study was to identify pre-operative and intra-operative factors that are predictive of dislocation following primary total hip replacement (THR). Data were prospectively collected for a consecutive series of 4334 THRs undertaken over a 14-year period. Ninety-eight (2.3%) of the 4334 patients had one or more dislocation post-operatively. A body mass index (BMI) of ≥ 35 (p < 0.001), a Harris Hip Score (HHS) of ≤ 41 (p < 0.001) and a low-volume surgeon (p < 0.001), which was defined as performing fewer than 43 THRs per annum, were identified as independent predictors of dislocation using logistic regression analysis. Using these three variables in differing combinations the risk of dislocation varied from 0.5 to 10.4%. Patients at high risk of dislocation, with a BMI of ≥ 35 and a pre-operative HHS of ≤ 41, undergoing surgery by a low-volume surgeon had a dislocation rate of 10.5%, but this decreased to 2.3% when operated on by a high-volume surgeon. These risk factors could be used to identify patients at high risk of dislocation, and modification of these factors, such as weight loss to achieve a BMI of ≤ 35 or referral to a high-volume surgeon, may decrease the risk of dislocation and the resulting secondary morbidity.

Changing trends in total knee replacement.

INTRODUCTION: This study evaluates a possible change in the demographics and surgical practice observed in a large cohort of patients undergoing total knee replacement (TKR). PATIENTS AND METHODS: We performed a retrospective analysis of a prospectively collected data on two groups of consecutive patients undergoing primary TKR. Group one consisted of patients who underwent surgery between 1994 and 1998. Group two consisted of patients who had surgery between 2009 and 2012. RESULTS: The mean age of group two was significantly greater than that of group one: 68.9 years (68.1-69.7 years) for group one versus 70.1 years (69.6-70.6 years) for group two (p = 0.009). The mean BMI of group two was significantly greater than that of group one: 29.5 kg/m2 (29.0-29.9 kg/m2) for group one versus 32.0 kg/m2 (31.7-32.3 kg/m2) for group two (p < 0.001). The mean pain component of the AKSS was significantly worse in group one than in group two: 28.6 (27.2-30.0) for group one versus 35.5 (34.6-36.4) for group two (p < 0.001). The mean function component of the AKSS was significantly worse in group one than in group two: 48.6 (47.3-49.9) for group one versus 51.5 (50.7-52.3) for group two (p < 0.001). CONCLUSION: This study describes the change in demographics of patients undergoing TKR in our institution over the last two decades.

Range of movement correlates with the Oxford knee score after total knee replacement: A prediction model and validation.

BACKGROUND: Patient reported outcome measures are widely used in the evaluation of outcomes after Total Knee Replacement (TKR) in joint registries and large studies. The aim of this study was to assess the relationship between the Oxford knee score (OKS) and range of motion (ROM) after TKR, and to construct and validate prediction models of ROM from the measured OKS. METHODS: Eight hundred sixty patients reviewed five years postoperatively and 273 patients reviewed nine to 10 years postoperatively completed an OKS. Of these, 808 (94%) and 226 (83%) patients, respectively, had a complete dataset (knee extension and ROM) and formed the study cohort. RESULTS: Regression analysis demonstrated a significant correlation between the OKS and ROM (r=0.38, p<0.001) after adjusting for other confounding variables (age, sex, body mass index, and knee extension). A prediction model was constructed and validated using a second cohort of 226 patients at nine to 10 years after their TKR. Intraclass correlation demonstrated good reliability (r=0.60, 95% CI 0.47 to 0.69) between predicted and actual measured ROM for this group. However, when the OKS is used in isolation the reliability of the predicted ROM is diminished (intraclass correlation r=0.41, 95% CI 0.24 to 0.55). CONCLUSIONS: The OKS is an independent predictor of ROM after TKR. It is also possible to predict ROM from the OKS, but the reliability of this is improved when other independent predictors such as age, gender, body mass index (BMI) and degree of knee extension are also acknowledged.

Metaphyseal Sleeves for Revision Total Knee Arthroplasty: Good Short-Term Outcomes.

Metaphyseal sleeve prostheses have shown promising results in the management of bone defects at revision TKA. We present a study of their use in aseptic revision TKA. Thirty-five revisions were included in 34 patients with wear or aseptic loosening indicated in 71% of cases. The majority of cases (63%) were AORI grade 2 or greater on the tibia or femur. Knee Society scores were excellent or good in 83% of patients with the same percentage having no or only mild pain. One patient suffered a sleeve-related complication with femoral condylar fractures three years postoperatively; these united with good outcomes. All radiographs were satisfactory; no patient required a further revision. We report good outcomes with the use of metaphyseal sleeves in revision TKA.

Longer hospital stay, more complications, and increased mortality but substantially improved function after knee replacement in older patients.

BACKGROUND AND PURPOSE: Total knee replacement (TKR) is being increasingly performed in elderly patients, yet there is little information on specific requirements and complication rates encountered by this group. We assessed whether elderly patients undergoing TKR had different length of stay, requirements, complication rates, and functional outcomes compared to younger counterparts. PATIENTS AND METHODS: We analyzed prospectively gathered data on 3,144 consecutive primary TKRs (in 2,092 patients aged less than 75 years, 694 patients aged between 75 and 80 years, and 358 patients aged over 80 years at the time of surgery). RESULTS: Incidence of blood transfusion, urinary catheterization, postoperative confusion, cardiac arrhythmia, and 1-year mortality increased with age, even after adjusting for confounding factors, whereas the incidences of chest infection and mortality at 1 month were highest in those aged 75-80. Rates of thromboembolism, prosthetic infection, and revision were similar in the 3 age groups. All groups showed similar substantial improvements in American Knee Society (AKS) knee scores, which were maintained at 5 years. Older patients had smaller improvements in AKS function score, which deteriorated between 3 and 5 years postoperatively, in contrast to the younger group. INTERPRETATION: Elderly people stand to gain considerably from TKR, particularly in terms of pain relief, and they should not be denied surgery based solely on age. However, they should be warned that they can expect a longer length of stay, a higher requirement for blood transfusion and/or urinary catheterization, and more medical complications postoperatively. Mortality was also higher in the older age groups. The risks have been quantified to assist in perioperative counselling, informed consent, and healthcare planning.

Estimating the transfusion risk following total knee arthroplasty.

Patients undergoing total knee arthroplasty (TKA) are likely to receive a blood transfusion, which may increase the risk of complications and prolong hospital stay. Considerable variation exists in transfusion practice among orthopedic surgeons following elective TKA. Previous studies have investigated the relationship between preoperative risk factors and the requirement for blood transfusions in patients undergoing a total hip or knee arthroplasty, but few have focused on transfusion risk in those specifically undergoing TKA.The authors performed a retrospective review of a prospectively collected database of 2281 patients undergoing unilateral TKA in a district general hospital over a 10-year period. Multiple regression analysis models were used to identify risk factors associated with postoperative blood transfusion. A predictive model was created based on the regression coefficients and factor levels. The risk of transfusion was independently predicted by the patients' age at surgery (P<.001), preoperative hemoglobin (P<.001), weight (P=.009) and lateral retinacular release (P<.001). The preoperative variables of age, hemoglobin, and weight were incorporated into a model to provide an estimation of the transfusion risk. The area under the receiver operating characteristic curve was 74% (95% confidence interval, 70%-77.5%). This study identifies risk factors independently associated with the risk of requiring a blood transfusion following TKA. The predictive model stratifies the risk according to the individual patient in the preoperative setting, allowing preventative measures to take place preoperatively. It also helps in the counseling of patients at high risk of requiring a postoperative blood transfusion.

Predictors of excellent early outcome after total hip arthroplasty.

BACKGROUND: Not all patients gain the same degree of improvement from total hip replacement and the reasons for this are not clear. Many investigators have assessed predictors of general outcome after hip surgery. This study is unique in its quest for the predictors of the best possible early outcome. METHODS: We prospectively collected data on 1318 total hip replacements. Prior to surgery patient characteristics, demographics and co-morbidities were documented. Hip function and general health was assessed using the Harris Hip score (HHS) and the Short-Form 36 respectively. The HHS was repeated at three years. We took a maximal HHS of 100 to represent an excellent outcome (102 patients). Multiple logistic regression analysis was used to identify independent predictors of excellent outcome. RESULTS: The two strongest predictive factors in achieving an excellent result were young age and a high pre-operative HHS (p = 0.001). CONCLUSIONS: It was the young and those less disabled from their arthritis that excelled at three years. When making a decision about the timing of hip arthroplasty surgery it is important to take into account the age and pre-operative function of the patient. Whether these patients continue to excel however will be the basis of future research.

Predictors and outcomes of lateral release in total knee arthroplasty: a cohort study of 1859 knees.

The use of lateral retinacular release (LR) to improve patellar tracking during total knee arthroplasty (TKR) remains contentious. This cohort study explored which pre-operative factors predicted LR, and analysed the effect of LR on short term complications and long term outcomes. One thousand eight hundred fifty-nine TKR patients were followed up for a mean of 5.49 years. One hundred fifty-four (8.3%) underwent LR. After regression analysis only, valgus deformity, year of surgery, maximal flexion and the operative surgeon predicted LR. LR patients stayed longer in hospital (10.8 vs 8.6 days) and had higher transfusion rates (20.3% vs 10.1%) than non-LR patients, but patellar fracture and infection rates were the same. Range of motion was poorer in the LR patients, but AKS Knee and functional scores were unaffected long term.

Unipolar versus bipolar uncemented hemiarthroplasty for elderly patients with displaced intracapsular femoral neck fractures.

PURPOSE: To compare outcomes of unipolar versus bipolar uncemented hemiarthroplasty and determine factors affecting outcomes. METHODS: 433 and 274 elderly patients with displaced intracapsular femoral neck fractures underwent uncemented unipolar hemiarthroplasty and uncemented bipolar hydroxyapatite-coated hemiarthroplasty, respectively. Surgical options were based on the patient's general condition and preinjury mobility status. In the respective groups, the mortality of 377 and 242 patients and the mobility of 270 and 217 patients were reviewed at the 4-month follow-up. Patient age, sex, American Society of Anesthesiologists [ASA] score, mobility, and mortality of the 2 groups were compared. RESULTS: Patients who underwent unipolar hemiarthroplasty were significantly older, less fit, and less mobile (p<0.001). Patients who underwent bipolar hemiarthroplasty achieved better outcomes for mortality and mobility (p<0.001). Among patients who were able to walk unaided before injury, more of those having bipolar hemiarthroplasty were able to do so at month 4 than those having unipolar hemiarthroplasty (13% vs. 33%, p<0.001). Mortality within 4 months was associated with age, male gender, and ASA score. When patients were stratified according to age groups, mortality within 4 months was lower in patients having bipolar hemiarthroplasty. CONCLUSION: In elderly patients with femoral neck fractures who were fit and physiologically young, uncemented bipolar hemiarthroplasty seemed to achieve better functional outcome.

Outlier analysis in orthopaedics: use of CUSUM: the Scottish Arthroplasty Project: shouldering the burden of improvement.

National joint registries have become well established across the world. Most registries track implant survival so that poorly performing implants can be removed from the market. The Scottish Arthroplasty Project was established in 1999 with the aim of encouraging continual improvement in the quality of care provided to joint replacement patients in Scotland. This aim has been achieved by using statistics to engage surgeons in the process of audit. We monitor easily identifiable end points of public concern and inform surgeons if they breach our statistical limits and become "outliers." Outlier status is often associated with poor implants, and our methods are therefore applicable for indirect implant surveillance. The present report describes the evolution of our statistical methodology, the processes that we use to promote positive changes in practice, and the improvements in patient outcomes that we have achieved. Failure need not be fatal, but failure to change almost always is. We describe the journey of both the Scottish Arthroplasty Project and the orthopaedic surgeons of Scotland to this realization.

Abnormal human chondrocyte morphology is related to increased levels of cell-associated IL-1ß and disruption to pericellular collagen type VI.

Early osteoarthritis (OA) is poorly understood, but abnormal chondrocyte morphology might be important. We studied IL-1ß and pericellular collagen type VI in morphologically normal and abnormal chondrocytes. In situ chondrocytes within explants from nondegenerate (grade 0/1) areas of human tibial plateaus (n = 21) were fluorescently labeled and visualized [2-photon laser scanning microscopy (2PLSM)]. Normal chondrocytes exhibited a "smooth" membrane surface, whereas abnormal cells were defined as demonstrating ≥1 cytoplasmic process. Abnormal chondrocytes were further classified by number and average length of cytoplasmic processes/cell. IL-1ß or collagen type VI associated with single chondrocytes were visualized by fluorescence immuno-histochemistry and confocal laser scanning microscopy (CLSM). Fluorescence was quantified as the number of positive voxels (i.e., 3D pixels with fluorescence above baseline)/cell. IL-1ß-associated fluorescence increased between normal and all abnormal cells in the superficial (99.7 ± 29.8 [11 (72)] vs. 784 ± 382 [15 (132)]; p = 0.04, positive voxels/cell) and deep zones (66.5 ± 29.4 [9 (64)] vs. 795 ± 224 [9 (56)]; p = 0.006). There was a correlation (r(2) = 0.988) between the number of processes/cell (0-5) and IL-1ß, and an increase particularly with short processes (≤5 µm; p = 0.022). Collagen type VI coverage and thickness decreased (p < 0.001 and p = 0.005, respectively) with development of processes. Abnormal chondrocytes in macroscopically nondegenerate cartilage demonstrated a marked increase in IL-1ß and loss of pericellular type VI collagen, changes that could lead to cartilage degeneration.

Incidence of knee arthroscopy in patients over 60 years of age in Scotland.

Arthroscopy has been utilised in the management of knee osteoarthritis for over 70 years but in recent years there has been growing debate about the efficacy of such treatment. We reviewed data from a national register, the Scottish Arthroplasty Project. We analysed 8897 knee arthroscopies performed in patients aged over 60 in Scotland between 1997 and 2006. Marked regional differences were noted for the rate of arthroscopy, with an upper rate of 230 arthroscopies per 100,000 age corrected population and a low of 80 per 100,000. No apparent reasons could be identified for this disparity. Regions with the highest rate of arthroscopy also had the highest rate of conversion to knee arthroplasty within 2 years, indicating a high level of ineffective and inappropriate arthroscopic surgery being performed in many areas of Scotland.

Unusual mode of mechanical failure of an AO cannulated self drilling screw. A case report.

Cannulated AO screws are commonly used for fracture fixation. Mechanical failure of screws has been well reported but this was mainly breakage of the screw head during removal. We report an unusual mode of failure of an AO self drilling cannulated screw which we have not previously experienced, where the screw threads were found to be unravelled during insertion. We also suggest the way to recognise this complication early and how to prevent or deal with it.

The complication rate and medium-term functional outcome after total hip replacement in smokers.

We aimed to study the effect of smoking on the complication rate and medium-term functional outcome after total hip replacement. 1767 patients undergoing a cemented THR in one hospital were followed up prospectively at 6, 18, 36, and 60 months. Harris Hip Scores, SF-36 scores and complications were recorded. There was no statistically significant difference in early complications and length of hospital stay between smokers and those patients who had never smoked. Smokers were less likely to require a blood transfusion and showed a statistically lower Harris Hip Score at six months but there was no difference seen at the subsequent time-points to five years after surgery. Smoking did not influence the complication rate or medium-term functional outcome at five years after total hip replacement.