Absorbable cement restrictors have been in use over the last few years. They have been shown to be as effective as the standard non-absorbable cement restrictors in achieving cement pressurisation and stopping distal cement migration in in vitro studies. The aim of this study is to compare in vivo, the effectiveness of absorbable with non-absorbable cement restrictors. One hundred and thirty-six consecutive patients who had total hip replacement performed using charnley cemented femoral prosthesis were selected and randomly divided in to two groups pre operatively. One group received Hardinge TM non-absorbable cement restrictor and the second group received Biostop TM absorbable cement restrictor. Type of the prosthesis, the surgical approach, the time from start of mixing of the cement to insertion of the cement (measure of viscosity of the cement), the cementing technique and the distance at which the cement restrictor was inserted were noted intraoperatively, the canal diameter was measured from the preoperative AP radiograph of the hip. The distance at which the cement restrictor was inserted was measured on the AP radiograph of the hip taken twenty-four hours postoperatively. All the above factors were statistically assessed as to their effect in the distal migration on cement restrictor using multiple regression analysis. There was no statistical difference between the two types of cement restrictors (P= 0.44). Surgeon, Surgical approach, femoral canal diameter P> 0.2 cementing technique P> 0.1 and Cement viscosity P= 0.082 had no effect on the degree of distal migration of the cement. In conclusion Biostop TM absorbable cement restrictor is as effective as Hardinge TM non-absorbable cement restrictor. We could not show any relationship between femoral canal diameter cementing technique and cement viscosity and distal cement migration which leads us to conclude that in the presence of adequate cement restriction these factors have little effect in distal migration of cement mantle

Background. Cement restrictors are used for maintaining good filling and pressurization of bone cement during hip and knee arthroplasties. The limitations of certain cement restrictors include the inability to accommodate for large medullary canals particularly in revision procedures. We describe a technique using SurgicelTM (Johnson & Johnson) and SPONGOSTAN™ (Johnson & Johnson) (Fig 1) to form a cement restrictor that can accommodate for large canal diameters and provide excellent pressurisation. Technique. The technique involves the application of SPONGOSTAN™ (Johnson & Johnson) foam onto a SurgicelTM (Johnson & Johnson) mesh which is then rolled onto the SPONGOSTAN™ foam forming a uniform cylindrical structure Figs 2,3. The diameter of the restrictor can be adjusted according to the desired femoral canal diameter through increasing the thickness of the SPONGOSTAN™ (Johnson & Johnson) foam. The restrictor is then inserted into the desired position in the medullary canal where it expands uniformly creating an effective restrictor and bone plug Fig 4. Bone cement is then applied and pressurisation commenced prior to the insertion of the implant Fig5. SPONGOSTAN™ is an absorbable haemostatic sponge intended for haemostatic use by applying to a bleeding surface. It consists of a sterile, water-insoluble, malleable, porcine gelatin absorbable sponge. Surgicel ™ is an absorbable hemostatic agent composed of oxidized regenerated cellulose. It is a sterile, absorbable knitted fabric that is flexible and adheres readily to bleeding surfaces. Both products are routinely used for their haemostatic properties in various surgical disciplines. Discussion. The use of intramedullary plugs in cemented total joint arthroplasty is essential in order to achieve good filling and pressurization in hip and knee arthoplasties, traditionally, a small piece of bone or a cement restrictor may be used to plug the shaft. Distal plugs seal the femoral canal, improve fixation and prevent bone cement from leaking during delivery and pressurization. Plugging the intramedullary canal during total hip arthroplasty increases penetration of cement into cancellous bone proximal to the intramedullary plug. Numerous plug designs and materials are available ranging from non-resorbable to resorbable. Regardless of design, all restrictors should avoid intramedullary cement leakage and plug migration during cement and stem insertion to ensure adequate intramedullary pressures. In some instances the diameter of the femoral canal is too wide to accommodate a conventional cement restrictor particularly when crossing the femoral isthmus and even more so in revision procedures requiring the implantation of long stemmed cemented components. The use of the Surgicel-Spongostan haemostatic restrictor overcomes some of the limitations of a standard cement restrictors. These include the ability to bypass a narrow femoral isthmus, accommodate large femoral canals, particularly in revision procedures, and the flexibility of adjusting the restrictor to the desired diameter of the medullary canal and in effect providing a bespoke cement restrictor. This technique was used successfully in over 300 revision hip and knee procedures with no adverse effects and excellent outcomes

Introduction: Following the introduction of a hip hemiarthroplasty monobloc a number of unusual problems occurred in our unit. These included the need for narrow stem prostheses, on table revision for excessive anteversion and intra-operative fracture, revision for irreducible dislocation and excision arthroplasty. It was noted that the trial component fitted easily whereas there were problems with insertion of the actual prostheses. Methods: To investigate the issue of differences in the trial component versus the actual prosthesis the following methods were employed. Digital micrometer measurements were taken from the trial and real components. Differences in the antero-posterior and medial-lateral dimensions of the components were analysed. Cross-sectional area analysis was also performed. The effect of femoral canal diameter on the insertion depth of trial and component was investigated using a canal model with digital image processing. The changes in cross-sectional geometry were investigated with respect to canal width, insertion depth and the consequential effect of component version. Results: It was shown that the trial was smaller than the actual prosthesis, particularly in the medial-lateral plane. No significant difference was observed between real components. A critical region of the component was identified which corresponded to a canal width of 10mm. Components not fully seated at this point drifted in to excessive anteversion with impaction. Discussion: This study identified that an unacceptable difference existed between the trial and real prosthesis. The study explained the effect of a narrow canal in terms of increased complications which resulted in increased morbidity for patients. Consequently the use of this implant was abandoned in narrow femoral canal cases and an alternative implant has been selected for use in fracture patients requiring hemiarthroplasty in our unit

Introduction: The anatomy of the proximal femur is an important factor in the design of uncemented femoral prostheses for which the quality of fixation and the associated bony remodelling depend on the primary stability and optimal transmission of forces to the proximal femur. This study looks at the variation in the diameter of the proximal femur with age and sex in a homogeneous population. Materials and Methods: We studied standardised pre-operative antero-posterior radiographs of the proximal femur of 2,777 patients who have undergone total hip arthroplasty using a custom implant over a 10 year period. The radiographs were corrected for magnification and a measurement made of the endosteal diameter at the narrowest point of the proximal femur. These measurements were used in the design and manufacture of the custom femoral implant. Results: Of 2777 patients, 1588 were female and 1189 male. The mean age for females was 69.9 years (Range 30–92) and for males 67.2 years (Range 34–92). The mean proximal femoral canal diameter was 12.67mm for females and 13.36mm for males. The mean diameter of the proximal femur increased from 12.99mm in males less than 60 years to 13.47mm in those of over 60. This increase was not statistically significant (p-value 0.064, 95% CI). In females there was a statistically significant increase in the mean diameter from 11.38mm in the under 60 age group to 12.90mm in those over 60 ( p-value 0.000, 95% CI). Conclusions: The increase in the diameter of the proximal femur with age especially in females presents a significant challenge to the design and long-term survivability of uncemented femoral components. This is more so when viewed against the already good long term results available for cemented femoral implants

Introduction: Intramedullary nailing is an acceptable method of treatment for femoral shaft fractures today. We present our experience from the use-of four different nails. Patients and Methods: Thirty fractures of the femoral shaft were treated by intramedullary nailing from Jan98–DecOl in our department. The patients’ age ranged from 19 to 87 (avg 36 ys). Twelve fractures were in poly-trauma patients. In 6 patients, due to an intense comminution, an external fixation was initially applied and a delayed intramedullary nailing was performed. Four different types of nails were used 8 Grosse & .Kempf, 1 Orthofix ,2 ZMS (Zimmer), and 19 Marchetti Vicenzi. Results: All patients were followed up until complete union of the fracture. A 1.5 cm shortening was found in one patient and two patients presented a valgus 7° at the fracture site. One pseudarthosis with broken implant (Marchetti) was seen and treated with a new nail of the same type. The Orthofix nail was used only once due to its lack of anatomic curvature. The mean surgical time of the GK and ZMS nails was 30 minutes more than that of Marchetti nails, due to the distal locking screws required. Conclusions: In our own experience, GK and ZMS nails provide a larger contact area in the endosteum as well as the best conditions for biomechanically sound distribution of loading. The placement of distal locking screws constitutes a major problem, as it requires extended surgical time and increased exposure to irradiation. The important advantage of the Marchetti nail is that no distal screws are required, so the operation and fluoroscopy time are much shorter. The main disadvantages of the Marchetti nail are the absence of quidewire during nail insertion, the minimal 13mm femoral canal diameter required proximally, the contraindication for very distal fractures and the inability to fully weightbear early

Aims

When performing revision total hip arthroplasty using diaphyseal-engaging titanium tapered stems (TTS), the recommended 3 to 4 cm of stem-cortical diaphyseal contact may not be available. In challenging cases such as these with only 2 cm of contact, can sufficient axial stability be achieved and what is the benefit of a prophylactic cable? This study sought to determine, first, whether a prophylactic cable allows for sufficient axial stability when the contact length is 2 cm, and second, if differing TTS taper angles (2° vs 3.5°) impact these results.