Introduction

We aim to assess whether radiographic characteristics of the greater tuberosity fragment can predict rotator cuff tears inpatients with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity.

Introduction

Although femoral neck fractures remain a concern in short term failures for hip resurfacing, acetabular component position and fixation are increasingly being recognized as causes of mid term failures for hip resurfacing. This study aimed to evaluate the migration pattern of a cobalt chrome, beaded acetabular component for a metal on metal hip resurfacing.

Introduction

Modern cementless press fit stems rely on early fixation and stability for osteointegration and longterm success with early migration increasing the risk of failure. The Ein Bild Roentegen Analyse Femoral Component Analysis (EBRA-FCA) methods allow accurate measurement of femoral stem subsidence without the need for Tantalum markers. The degree of subsidence of femoral stems in the first two years has been shown to be highly predictive of failure when using the cut off value of 1.5 mm. We aimed to measure the early migration pattern of a titanium alloy, tapered, plasma and hydroxyapatite coated femoral stem and any factors associated with subsidence.

Fractures of the Proximal Femur are a common and disabling injury requiring hospital admission and surgical treatment leading to approximately 86,000 inpatient episodes annually in the UK, with such patients occupying more than 20% of NHS orthopaedic beds. Based on current trends the number of hip fractures may rise to 120,000 per annum by 2015.

As the age of the population increases, so does the prevalence of concomitant medical conditions. Atrial Fibrillation is rising in the general population. Recently, the benefit of treating these patients with warfarin to prevent stroke has been shown; as a consequence, the number of patients being treated with warfarin is on the increase.

We have performed a retrospective study of all patients admitted to our unit with Fractures of the neck of the femur between 2001 and 2006, from the Accident and Emergency department with a primary diagnosis of Proximal Femoral Fracture (1987 patients). 138 patients were on long term warfarin at the time of their admission (6.9% of admissions). 90.4% were being warfarinised for AF, 7.6% for DVT and the rest for other indications. Of these Patients only 12 (8.7%) received active reversal to their warfarin. (All received vitamin K either orally or Intravenously). The average delay to theatre attributable to warfarin therapy was 41.1 hours (p-0.001). Active reversal allowed this delay to be negated (p-0.01), and did not delay the reloading of warfarin post-operatively (p-0.012). It also allowed an average of 10.2 days earlier discharge from the orthopaedic unit (p-0.001).

This study shows that significant delays occur because of Warfarinisation of these patients and that active reversal seems to be beneficial in expediting surgical treatment and discharge from the orthopaedic unit.

In cerebral palsy patients, while upper limb function is acknowledged as being important, it has traditionally taken a back seat to lower limb function. This is partly due to inexperience and partly due to difficulty deciding on the best way of improving upper limb function.

In Swansea since June 2008 we have been offering a multi-disciplinary service for the assessment and treatment of upper limb problems in cerebral palsy. The core team consists of a consultant orthopaedic surgeon, a consultant plastic surgeon with a special interest in CP upper limb problems, a consultant paediatric neurologist, a community paediatric physiotherapist and a community paediatric occupational therapist.

Upon referral, the physiotherapist and occupational therapist carry out initial functional assessment of the patient. This is followed by a joint assessment by the whole team in a special clinic held every 3 months. If required, the child is offered surgery, botox injections or both. Further follow-up is in the special clinic until the child is suitable for follow-up in a normal clinic.

We present our initial experience with this multi-disciplinary approach, the problems encountered in setting up the service and our plans for the future.

Given that there is limited time available to the surgeon in arthroscopic rotator cuff repair, how is the time best spent? Should they place one Modified Mason-Allen, two mattress or four simple sutures? This study reverses current thought. In an in-vitro biomechanical single pull to failure study we compared the ultimate tensile strength of simple, mattress and grasping sutures passed with an arthroscopic suture passer (Surgical Solutions Express-Sew). The aim was to determine which suture configurations would most simply, repeatably and reliably repair the rotator cuff.

The ultimate tensile strength and mode of failure of six different suture configurations was repeatedly tested on a validated porcine rotator cuff tendon model, using a standard suture material (Number 2 Fiberwire) passed with the Surgical Solutions Express-sew, in a Hounsfield type H20K-W digital tensometer.

Standardising the number of suture passes to four, the strongest construct was two mattress sutures (Mean 169N), followed by single Modified Kessler (Mean 161N), four simple sutures (Mean 155N) and finally a single Mason Allen suture (Mean 140N). Suture configurations involving two passes were all weaker than those with four (one way analysis of variance p=0.026), even when Number 2 Fibertape was used to augment strength.

These results show little difference in strength for varying complexity of four pass suture passage (one way analysis of variance p=0.61). In simple terms there is no demonstrable difference in the strength of construct whether the surgeon uses four simple, two mattress or one grasping suture. This study allows the surgeon to justify using the simplest configuration of suture passage that works in his hands in order to obtain a reliable and repeatable repair of the rotator cuff arthroscopically.

Purpose: Although femoral neck fractures remain a concern in terms of short term failures for hip resurfacing, acetabular component position and fixation are increasingly being recognized as causes of mid term failures for hip resurfacing. The purpose of our study was to evaluate the migration pattern of a cementless acetabular component for a metal on metal hip resurfacing.

Method: Between January 2006 and June 2007, 130 patients underwent metal on metal hip resurfacing; 66 hips in 60 patients were included in this analysis. Forty-eight patients were male and 12 were female, with a mean age of 50 (range, 32–66). Ninety-five percent of the surgeries were performed for osteoarthritis. All surgeries were performed by two surgeons using the Conserve Plus (Wright Medical Technology, Memphis, TN) hip resurfacing system. The acetabular component is a monoblock cobalt chrome with a porous beaded surface for osteointegration. In all cases acetabular migration was measured both vertically and horizontally, on serial radiographs using the computer-assisted Ein Bild Röntgen Analyse (EBRA) method. A minimum of three comparable radiographs is necessary for calculating the migration curves. We scored medial migration as negative horizontal movement.

Results: At a mean follow up 25.3 months (range, 24–36 months), each hip had an average of 5.1 radiographs for analysis. The software excluded two cases for poor comparability ending finally with 64 cases for the analysis. Eighty-seven point five per cent of the cups showed less than 1 mm migration in the medium-lateral axis and 54.7% less than 1 mm in the vertical axis. Seventy-seven percent of the cups showed a combined migration of less than 2 mm in the observation period, without radiolucencies, leaving 23% of the acetabular components with 2 mm or greater of component migration. One of these cases required revision for aseptic loosening at 34 months.

Conclusion: In our study the majority of the acetabular components were stable with some of the migration observed secondary to lack of complete initial seating due to the rigidity of the shell. Krismer et al did report on the migration of the PCA shell (also a porous beaded cobalt-chrome shell) using EBRA, with 27.5% of the shells demonstrating > 1 mm of migration. Although hip resurfacing has only mid term followup, results have been good to excellent. Caution should still be maintained since the higher frictional torque generated by the larger femoral head size as well as the nanometer size particles could negatively affect long term fixation of the acetabular component.

Purpose: We aimed to measure the early migration pattern of a titanium alloy, tapered, plasma and hydroxyapatite coated femoral stem and any factors associated with subsidence.

Method: Between January 2005–June 2007, 387 Accolade cementless femoral stems (Stryker, Allendale NJ) were implanted at our institution. Seventy-seven had a minimum of two years post operative follow up and a complete set of pre and postoperative radiographs for analysis. Our group inlcuded 45 females with a mean age of 71.4 years, and 32 males with a mean age of 68.5 years. The primary diagnosis was degenerative osteoarthritis in 71 patients, avascular necrosis in two, and post fracture in four patients. The average BMI was 27.1. We measured the canal index to assess bone quality and the canal calcar index to assess the proximal femoral morphology. Immediate postoperative radiographs were assessed for canal fill of the prosthesis and implantation varus/valgus angles. The EBRA-FCA software was used to obtain migration curves for each stem. Best fit curve of subsidence over time was calculated and the data was analysed using a Kaplan Meier survivorship with 1.5 mm of subsidence as an endpoint. We then performed a multivariate and univariate regression analysis for predictors of subsidence.

Results: The mean follow up was 29.3months (24–48). The mean canal index was 0.55 (0.36–0.68) with a mean canal calcar index of 0.54 (0.39–0.79). The average canal fill index at the midpoint of the stem was 80 in 40 stems. A total of 414 radiographs were analysed for the EBRA measurements. Of these 21 (5%) were discarded by the software as they did not meet the criteria for comparability. This led to the exclusion of seven patients, leaving the final study group of 77. All remaining patients had a minimum of four radiographs with an average of 4.6 for analysis. The average subsidence at 24 months was 2 mm and this had risen to 2.4 mm by 36 months postoperatively. When analysed using a Kaplan Meier curve using 1.5 mm as an end point we found a survivorship of 63.4% (52.3–74.5) at 24 months and this had worsened to 41.6% (26.6–56.5) by 36 months. Multivariate and univariate regression analysis of measured variables did not reveal any significant hazard for any factor other than the larger stem sizes doing worse.

Conclusion: Although several cementless tapered stem designs have had an excellent track record, our migration analysis of the Accolade stem is somewhat concerning. Thirty three percent of stems had reached the 1.5 mm subsidence point by two years. This is of concern as work has previously shown this to predict failure of stems with aseptic loosening at ten years with an accuracy of 79%. If these stems go on to fail at the predicted rate this would represent an unacceptably high level of failure. Our data raises serious concerns about the overall clinical performance of this stem design due to poor initial stability and integration.

Given that there is limited time available to the surgeon in arthroscopic rotator cuff repair, how is the time best spent? Should he place one Modified Mason-Allen, two mattress or four simple sutures? This study reverses current thought. In an in-vitro biomechanical single pull to failure study we compared the ultimate tensile strength of simple, mattress and grasping sutures passed with an arthroscopic suture passer (Surgical Solutions Express-Sew). The aim was to determine which suture configurations would most simply, repeatably and reliably repair the rotator cuff. The ultimate tensile strength and mode of failure of six different suture configurations was repeatedly tested on a validated porcine rotator cuff tendon model, using a standard suture material (Number 2 Fiberwire) passed with the Surgical Solutions Express-sew, in a Hounsfield type H20K-W digital tensometer. Standardising the number of suture passes to four, the strongest construct was two mattress sutures (Mean 169N), followed by single Modified Kessler (Mean 161N), four simple sutures (Mean 155N) and finally a single Mason Allen suture (Mean 140N). Suture configurations involving two passes were all weaker than those with four (one way analysis of variance p=0.026), even when Number 2 Fibertape was used to augment strength. These results show little difference in strength for varying complexity of four pass suture passage (one way analysis of variance p=0.61). In simple terms there is no demonstrable difference in the strength of construct whether the surgeon uses four simple, two mattress or one grasping suture. This study allows the surgeon to justify using the simplest configuration of suture passage that works in his hands in order to obtain a reliable and repeatable repair of the rotator cuff arthroscopically.

The aim of this study was to determine the incidence of second hip fracture.

A prospective cohort study include 2682 patients aged 50 years or more admitted with a hip fracture over a 4 year period. Mortality data were available for all patients and survival analysis was performed to determine the incidence of second hip fracture. The mean age-specific incidence rates of primary hip fracture in the population were calculated to serve as a baseline.

95 patients (3.5%) sustained a sequential, contralateral hip fracture within the study period. The mean age at first hip fracture was 82 years and the mean interval between fractures was 316 days. Fracture morphology was similar on both sides in 69% of cases. Survival analysis demonstrated that the incidence of second hip fracture at 1 year was 2.8% (95% CI: 2.0–3.6), 2 years was 5.7% (95% CI: 4.3–7.1) and 3 years was 7.3% (95% CI: 5.4–9.2). The relative risk of hip fracture in patients who had already sustained one hip fracture was 2.4 times above that of matched controls. Assistance with activities of daily living was identified as a risk for second hip fracture (p=0.026, 95% CI: 1.058, 2.466). The odds ratio for sustaining a second hip fracture compared with the incidence of primary hip fracture in the normal population aged 55–64 years was 47.5 xs; 65–74 years was 15 xs; 75–84 years was 3.7x and 85+ years was 1x.

The risk of sustaining a second contralateral hip fracture is substantial. In younger patients preventative measures can be targeted at the individual who has sustained a fracture whereas in more elderly patients, preventative measures need to address the population as a whole.

In 1997 the “step-less” SL Plus (Endoprothetik, Rotkreuz, Switzerland) cementless total hip arthroplasty was introduced to our unit. During the passed 12 months, a retrospective study has been performed in order to evaluate the clinical and radiographic results of this arthroplasty. The preliminary results of the first 50 patients to have completed the clinical and radiographic follow-up have been evaluated. Of the 50 patients, 56 primary total hip arthroplasties were performed, in all cases the SL Plus stem was used. In 52 cases the cementless Doetz acetabular cup, made by the same manufacturer, was used. The other 4 acetabular components were: 2 long stemmed cementless components for developmental dysplasia, 1 standard cementless cup and 1 cemented cup, made by other manufacturers. All patients were reviewed clinically and radiographically. The mean follow-up time was 3 years, range 2 – 5 years. The mean Harris Hip Score was 90 (37 – 100). Patient satisfaction was: 98% satisfied, 2% dissatisfied (p < 0.001). Radiographic assessment demonstrated that all 52 (100%) Doetz acetabular cups osseointegrated, with 53 (95%) acetabular cups osseointegrating in total (p < 0.002). Of the SL Plus stems, 44 (79%) osseointegrated (p < 0.002). The following post-operative complications were observed: 2 dislocations, 2 superficial wound infections, 1 myocardial infarction, 1 sciatic nerve palsy and 1 deep vein thrombosis. The overall complication rate is high at 13%, but with no implant related failures. Nevertheless, the preliminary clinical and radiographic results of the SL Plus stem and Doetz acetabu-lar cup total hip arthroplasty are encouraging.