Aim

The purpose of this study was to quantify the number of children treated with ESIN (elastic stable intra-medullary nails) at our institution and to determine what proportion of these nails have been removed and the time and difficulty taken to do so.

Introduction

Total hip replacements using highly cross-linked polyethylene show excellent clinical outcomes, low wear, and minimal lysis at 5 years follow-up. A recent RSA study reports a significant increase in femoral head penetration between 5 and 7 years. This study is a multi-center radiographic analysis to determine whether the RSA observation is present in a large patient cohort.

Introduction: Leg length inequality (LLI) following arthroplasty, though often asymptomatic, can be cause for considerable morbidity and has increasing medicolegal consequences.

There are various methods of quantifying leg length inequality on plain AP radiograph. The aim of this study is to review the established practice in the measurement of leg length inequality and compare it to two methods used locally.

Methods: This is a retrospective study assessing the radiographs of 35 patients with a mix of native, unilateral and bilateral total hip arthroplasty. Two methods of measuring leg length inequality were prominent in the literature, the Woolson method and the Williamson method. A further two methods are used locally. Measurements for all four techniques were made by two senior consultant radiologist to on the trust PACS to assess inter and intra observer variability. Data analysis was performed using SPS 16 to produce intraclass correlation co-efficient (ICC) and Bland Altman plots.

Results: ICC for all methods in the measurement of LLI is excellent (≥0.90). The repeatability ICC for the four methods is; Woolson 0.65, Williamson 0.87, Direct 0.96 and the Leeds method 0.95.

Discussion: This study demonstrates that all four methods have excellent correlation; however the repeatability is better for the Direct and the Leeds methods than the two that are more widely used in the literature. While the Direct measurement is able to give an overall measurement for the leg length inequality, the Leeds method is able to distinguish between any inequality due to cup malpostion and stem malposition. It is therefore of particular value in the assessment of bilateral or revision arthroplasty and the audit of practice.

Studies of patients having primary THR using highly cross-linked polyethylene show excellent clinical outcomes and very low radiographic wear results at a minimum of 5 years follow-up. Recently, a radiostereometric analysis (RSA) study of a small group of patients reported that after no detectable wear during years 1–5, they found a significant increase in femoral head penetration between 5 and 7 years follow-up. However, this increase in head penetration after 5 years has not been confirmed in a larger patient cohort.

The purpose of this study was to organize a multicenter radiographic study involving leading medical centers in the U.S. having the longest-term follow-up available on this type of highly cross-linked polyethylene in order to determine if the RSA observation can be confirmed in a larger study.

Six academic centers agreed to contribute radiographic data to this study. All patients received primary total hip replacements with Longevity polyethylene liners (Zimmer, Warsaw, IN) coupled with 26, 28, and 32mm cobalt chrome femoral heads. The radiographic inclusion criteria required a minimum of four radiographs per patient: one at 1 year; at least one from 2 to 4.5 years; one 4.5 to 5.5 years; and at least one from 5.5 to 9 years follow-up. The Martell Hip Analysis Suit-eTM software was used for the wear analysis. All wear values were determined by calculating head penetration between the follow-up radiograph and the 1-year radiograph to remove creep, the majority of which has been shown to occur during the first year. Separate linear regressions, representing the wear rates, were computed for the early period from 1 year to 5.5 years and the late period from 5.5 years to 9 years follow-up. The Zar test was used to determine the significance of the difference between these two linear regressions.

We present the completed analysis of 165 hips. When the early and late data points were combined into one data set, the second-order regression indicated an inflection point at 6.3 years with a slightly positive inflection. There were 402 film comparisons in the early time period, and the slope and confidence interval of the regression line was 4.9μm/yr (95% CI of −28μm/yr to 38μm/yr). There were 188 film comparisons in the late period, and slope of the regression line for the late period was 10.8 μm/yr (95% CI of −58μm/yr to 80μm/yr). The Zar test showed no significant difference between the two slopes (Figure 1, p=0.886).

No significant increase in femoral head penetration was found for the late period after 5 years compared to the early period before 5 years follow-up in either analysis. Additionally, no significant late increase in wear was seen within individuals. While we continue to enroll patients, at this time we do not observe the increase in wear seen in the RSA study after 5 years.

Aim: Isotope bone scan has become a part of the routine workup for a painful arthroplasty. A retrospective analysis was performed to analyse the significance of isotope bone scan results in the management of painful arthroplasty.

Methods and Materials: The study group included all the 58 consecutive patients who underwent an isotope bone scan for a painful arthroplasty over a one year period. The data collected included: age, sex, date and nature of primary arthroplasty, inflammatory markers, indication, date and result of the bone scan, and the final outcome.

Results: The primary arthroplasty was a TKR (29 patients) and THR (29 patients). The average duration between primary arthroplasty and the bone scan was 44.3 months (Range 5 – 195 months). The duration was less than 1 year for 6 patients. The average age of the patients was 62 years. The male: female ratio was 31:27. 4 of the arthroplasties were uncemented and 54 were cemented. The bone scan results were normal in 32 patients, unclear in 17 patients and abnormal in 9 patients. There was no statistical correlation found between the inflammatory markers and the results of the bone scan.

Discussion: The results of the bone scan made a significant contribution in the management decision of the patient in 8 of the patients and served to reassure the patient/surgeon in most of the rest 50. In 6 patients it was performed within a year of the primary arthroplasty, during which period the results are not very specific. An isotope bone scan involves a significant radiation exposure to the patient as well utilization of time and resources, hence always ask the million dollar question: “Is it going to alter my management plan”

Purpose: Bone grafting of subchondral voids during ORIF of tibial plateau fractures is commonly performed. The efficacy of various graft materials to resist post-operative articular displacement and stimulate bone regeneration in the grafted zone, remains largely unstudied. Studies in animals with a new composite material have shown that this composite material leads to greater bone formation and stronger bone versus autograft at 13 and 26 weeks. This study was designed to determine whether this material helps resist articular fragment displacement and leads to stronger bone regeneration and better functional outcome in the treatment of tibial plateau fractures.

Methods: Thirty four patients with unilateral tibial plateau fractures (OTA 41A-B), were enrolled in a prospective multicenter single cohort study. The treatment protocol included ORIF and defect augmentation with a composite bone graft substitute (PRODENSE®, Wright Medical Technology). Reduction and bone formation was evaluated and followed with both plain radiographs and CT scans obtained immediately postop and at 12 and 24 weeks. Functional outcome was assessed using the SMFA scores. CT analysis was performed by an independent musculoskeletal radiologist who quantified maintenance of reduction of the articular surface and bone density within the grafted area.

Results: Eighteen of the 34 enrolled patients were eligible for follow-up at 24 weeks (sixteen were not yet eligible for the 24 week time point). Mean change in articular reduction was 0.75mm, Density measures in the region of the initial subchondral void decreased from a mean of 1400 Hounsfield units at baseline (immediately post-op) to 600 at 24 weeks, suggesting bone regeneration and normal remodeling. Short form Musculoskeletal Function Assessment activity scores improved from 55.15 (SD=42.8) at baseline to 20.92 (SD=18.09) at 24 weeks. Complications include 1 DVT, 3 infections and 1 cellulitis, all of which resolved. There was an additional infection that required revision of the ORIF.

Conclusions and Significance: Serial CT evaluations revealed maintenance of post-operative reduction with displacement of less than 1mm. Bone density, in the region of the grafted area was near normal and confirms that the composite graft material promotes strong bone regeneration. Functional outcomes improved with time from surgery and approached that of uninjured cohorts.

Background: A common complication of lumbar spine surgery is incidental tear of the dural sac and subsequent leakage of the cerebrospinal fluid intraoperatively. Studies have reported a wide variation in the rates of dural tears in spine surgery (1%–17%). The rates were higher after revision surgery.

Objective: To establish a baseline rate of incidence of dural tears after lumbar surgery in Morriston Hospital Neurosurgical Unit and to compare it with the results reported in the literature.

Methods and Results: A prospective review of the operation notes of 65 consecutive patients who had undergone lumbar surgery (Primary lumbar discectomy, primary lumbar laminectomy and revision lumbar discectomy) over a period of 3 months from Jan 2008. Patients were operated on by different neurosurgical consultants.

40 patients had primary lumbar discectomy of which 2 (5%) had dural tears. 20 patients had primary lumbar laminectomy of which 1 (5%) had a dural tear and 5 patients had revision lumbar discectomy of which 1 (20%) had a dural tear. All dural tears were repaired intraoperatively.

Conclusion: This study shows that the highest percentage of incidental durotomy was in revision lumbar surgery which was also slightly higher than the reported rates (8.1%–17.4%). The percentage of dural tears after primary discectomy and primary laminectomy was within range of the percentages reported in the literature (1%–7.1%) and (3.1%–13%) respectively. A multicentre prospective larger study which includes all different surgical procedures performed on the lumbar spine is needed to establish a more accurate incidence rate for this common complication.

Purpose of study: To evaluate the clinical outcome of operative intervention for chronic patellar instability for patients treated by a single paediatric orthopaedic surgeon over a 74-month period

Method: There were 11 patients (16 knees) with a mean age at operation of 11.9 years (5 to 17 years). Patients were treated with combined proximal and distal patellar realignment. Mean follow-up was 44.6 months (11–86 months). All patients were assessed post-operatively with satisfaction scores, the Trillat grading system and the Activity Scale for Kids (ASK). They were also questioned specifically for patellofemoral symptoms and examined for signs of mal-tracking.

Results: Subjective patient rating of all procedures revealed 10 (62.5%) responses of excellent or very good, 4 (25%) good, 1 (6.25%) fair and 1 poor (6.25%). Formal Trillat grading revealed 9 (56.3%) excellent, 6 (37.5%) good, 1 (6.2%) fair and no poor outcomes. The mean ASK score was 82% (39–100%). All except one patient felt that they would choose to undergo the surgery again. There was one complication of a superficial wound infection.

Conclusions: These results show improvement in symptoms and function as judged by Trillat grading and a majority of patients satisfied with the results of the procedure. We feel that the advantage of appropriate surgical intervention at a young age is not only the improvement in symptoms, but also that successful realignment of patellar tracking may reduce subsequent degenerative problems associated with chronic instability and allow better rehabilitation of the dynamic stabilisers of the patellofemoral joint.

Cementless total hip replacements (THR) have a theoretical advantage over cemented designs in that bone lysis and probably aseptic loosening are less common complications. NICE guidelines suggest that prosthesis should have an aseptic loosening rate of < 10% at 10 years. Long-term follow-up of the Joint Replacement Instrumentation (JRI) Hydroxyapatite coated (HAC) Furlong system is gradually emerging following its first clinical application in 1985.

A retrospective study was performed to identify all patients having undergone a primary JRI HAC THR under a single Consultant at Barnsley Foundation Hospital NHS Trust between 1985 and 1995. This identified 124 joints in 106 patients (52% males). All living patients were sent a modified Oxford Hip Score questionnaire; case notes were also reviewed to identify any revision surgeries.

Median age at operation was 54.0 years. 17 patients (16%) had died at the time of this study. Median follow-up was 13.7 years (range 9.4–18.5 years). For 30 patients (24.2%) it was impossible to gather data on the survival of the hip.

Mean survival of all hips followed up was 16.2 years. Twenty-four hips (19.4%) required revision surgery; the median time to this surgery was 10.2 years, mean 8.2 years. Reasons included aseptic loosening of the stem in one patient at 12.7 years, aseptic loosening of the cup in 7 patients (range 10.2–17.4 years), worn polythene insert in 4 patients, infective loosening in 3 patients and recurrent dislocations in 2 patients. The remainder of revisions were for unknown reasons.

The Oxford Hip Score postal questionnaire was returned by 79% of patients. Mean score was 12.6/45 but 88% of patients reported overall satisfaction with the hip.

In summary, there were no revision surgeries at ten-year follow-up for aseptic loosening.

Total hip arthroplasty (THA) patients often require peri-operative blood transfusion. Variables that predict transfusion requirement may allow us to target cross-matching of individual patients.

153 patients underwent primary unilateral THA for osteoarthritis or rheumatoid arthritis during 2002 in our institution. 75 casenotes from these subjects were reviewed. Age, sex, diagnosis, weight, height, pre-operative haemoglobin (Hb) and haematocrit (Hct), anticoagulation type and timing were recorded, along with post-operative Hb and timing and quantity of any blood transfusion. Potential predictors of transfusion were examined using logistic regression analysis. ROC analysis was used to compare the relative predictive value of significant variables.

Mean (±SD) age at surgery was 67±11 years (53% females). Mean pre-operative Hb was 13.8±1.4g/dl, mean post-operative Hb was 10.2±1.0g/dl. 27 patients (36%) needed a transfusion; the most frequently given volume was 2 units and the mean number of units given was 0.85. The most common reason for transfusion was an asymptomatic low Hb (< 8.0g/dl). Pre-operative Hb and Hct were predictive of post-operative transfusion (logistic regression analysis P< 0.01). Age, gender, diagnosis and anticoagulation were not predictive. Using ROC analysis the optimal ‘cut-off’ value of pre-op Hb as a predictor was 12.7 g/dl, giving a sensitivity of 41% and a specificity of 88% for blood transfusion requirement. The optimal ‘cut-off’ for Hct was 0.41, sensitivity 74% and specificity 61%. There was no significant difference in the overall predictive value between these variables (comparison of area under ROC curves, P> 0.05).

In summary, subjects with a pre-operative Hb< 12.7 or Hct < 0.41 are more likely to require a blood transfusion after unilateral primary THA than those with an Hb or Hct above these values. In treatment centres where cross-matched blood is not available at short notice on demand, pre-operative cross-match of patients with blood counts below these values may be appropriate.