Introduction

Although total hip replacement (THR) has been described as the operation of the century, there is still room for improvement. There is therefore continued effort for advanced implants and bearing surfaces, moreover so, for the younger patient with a longer life expectancy and increased needs.

Introduction: There is extensive literature on the effect of vancomycin on the compression strength of plain cements, none however on antibiotic-loaded cements. The addition of vancomycin to antibiotic-loaded bone cement is common practice in revision joint replacement surgery for infection. The scope of this study was to record the effect of vancomycin addition on the compression strength of antibiotic-loaded bone cement and to compare the results with the international standard (ISO 5833–2) in order to evaluate safety in clinical use.

Materials & Methods: The formulations used were Palamed G, containing 0.55g of gentamicin; and Copal, containing 1g of gentamicin and 1g of clindamicin. Vancomycin concentrations of 2.5%, 5% and 10% per powder weight were added. The ISO requirements for the testing procedures were followed. Samples of Palamed G with 5% vancomycin and non-standardised mixing procedures were also tested, as well as samples of both bone cements without vancomycin, as controls.

Results: The mean compression strength of plain Palamed G was 91.08 MPa. With the addition of 2.5%, 5% and 10% vancomycin, the mean compression strengths were 79.82, 82.3 and 74.56 MPa respectively, a reduction of 12.36%, 9.64% and 18.13%. The mean strength of the Palamed G specimens with 5% vancomycin and non-standardised mixing was 72.88 MPa, a 19.9% reduction. The mean compression strength of the plain Copal was 86.27 MPa. With the addition of 2.5%, 5% and 10% vancomycin, the mean compression strengths were 76.59, 78.92 and 71.19 MPa respectively, a reduction of 11.22%, 8.52% and 17.48%. Copal with 10% and Palamed G with 5% vancomycin and non-standardised mixing, were the only cements with compression strengths not significantly exceeding the ISO standard of 70 MPa.

Conclusion: The addition of up to 5% vancomycin per powder weight to the antibiotic-loaded Copal and 10% to Palamed G bone cements can be considered safe. Care should be given to the mixing procedure of the cement, as it significantly affects its compression strength.

Aims: Resurfacing arthroplasty of the hip is increasing in popularity. Recently concerns have been raised about resorbtion of the femoral neck after hip resurfacing, which may increase the risk of femoral neck fracture. We conducted a study to assess the degree of femoral neck resorbtion after using a cemented femoral component at hip resurfacing arthroplasty and to compare this with an uncemented femoral component.

Patients and Methods: We included 130 patients who had undergone a hip resurfacing arthroplasty in our study. Our uncemented group included 70 consecutive patients who had received an uncemented Cormet hip resurfacing arthroplasty (Corin, Cirencester, UK). Our cemented group included 60 patients who had received a cemented Birmingham hip resurfacing arthroplasty (Smith and Nephew, Cambridge, UK). All patients were regularly followed up for a minimum of two years. Clinical outcome was assessed using Harris hip scores. Femoral neck resorbtion was assessed by measuring the cup-neck ratio on post-operative radiographs by two independent observers.

Results: The mean age of the patients was 50.7 years for the cemented resurfacing group and 51.5 years for the uncemented resurfacing group. No difference was found in Harris hip scores between the two groups at any of the follow-up periods. The overall survival rate at two years was 100% for the cemented group and 98.6% for the uncemented group. There was however, a significant increase in femoral neck resorbtion for the cemented resurfacing group compared to the uncemented resurfacing group (median cup-neck ratio 1.11 vs. 1.04), p< 0.0001

Conclusion: We found a significant increase in femoral neck resorbtion with the use of a cemented femoral component at hip resurfacing arthroplasty compared with an uncemented femoral component. This may increase the risk of femoral neck fracture and could affect the long-term outcome if a cemented femoral component is used.

Metal-on-metal hip resurfacing arthroplasty has been reintroduced as an alternative to total hip replacement. Uncemented acetabular fixation is now the gold standard for this procedure. However, uncemented femoral component fixation is less common. We thus report our preliminary results of an uncemented, hydroxyapatite-coated femoral implant at resurfacing arthroplasty. Between June 2001 and July 2002 we undertook 70 uncemented resurfacings in 66 patients. The survival rate of the femoral implants after a minimum of two years’ follow-up was 98.6%. The mean Harris hip scores for pain and function pre-operatively were 12.0 (maximum possible score 44) and 28.3 (maximum possible score 47) respectively. Postoperatively, at final follow-up, these scores were 39.25 and 43.07 respectively (Z= −6.94, p< 0.0001 for function and Z= −7.19, p< 0.0001 for pain). There have been no femoral fractures, aseptic loosening or radiolucencies around the stem. Thinning of the femoral neck at the inferomedial cup-neck rim has been a frequent radiological finding but with no clinical implications so far. The cup-neck ratio immediately after surgery was a mean of 1.05 while at last follow-up was 1.1 and this difference was statistically significant (Z= −4.14, p< 0.0001). Increased height (p=0.02) seemed to protect patients against neck thinning, whereas increased weight (p=0.06) seemed to favour it. Our preliminary results with a hydroxyapatite-coated femoral implant in metal-on-metal hip resurfacing have been promising with excellent survival rates and clinical outcomes. Longer follow-up studies are needed, particularly to interpret the clinical significance of neck thinning

It has been suggested that smaller skin incisions may be associated with a better short-term outcome after total hip replacement, including a more rapid rehabilitation. The definition of mini-incision is still unclear as publications with incisions ranging from five to 20 cms appear in the literature. We therefore prospectively studied 42 consecutive patients who had undergone 44 total hip replacements using a posterolateral approach, through skin incisions of between 10 and 21 cm. The patients were assessed for their speed of post-operative rehabilitation and their length of hospital stay. Age, body mass index, length of incision, duration of procedure, muscles detached and repaired, and blood loss were also recorded. We found no evidence of a correlation between incision size and blood loss, post-operative rehabilitation, or the length of hospital stay. Similarly, the degree of surgical muscle trauma showed no evidence of a correlation with the speed of post-operative rehabilitation or the length of hospital stay. In contrast, the age of the patient did significantly correlate with the length of hospital stay and rehabilitation scores. Our study showed no evidence that the size of the incision, or the muscles detached or repaired at surgery, influenced the immediate post-operative rehabilitation after total hip replacement performed through a posterior approach. Only the patient’s age showed a correlation with the speed of rehabilitation.

Hip resurfacing arthroplasty (RS) is said to be an operation that is suitable for the younger osteoarthritic population, allowing them to rehabilitate more rapidly. We wished to establish whether this was true and compared 35 consecutive RS (33 patients) with 41 consecutive total hip replacements (THR) (40 patients) and looked specifically at post-operative pain, speed of rehabilitation and length of hospital stay. A rehabilitation score was used. RS patients were significantly younger than THR patients (mean 53.0 years for RS, 64.7 years for THR; p< 0.0001). However, no significant difference was found in the mean rehabilitation score at any stage after surgery or in the speed of rehabilitation between the two groups. The mean pain score for group RS was 1.98 and 2.18 for group THR. The mean length of hospital stay was 5.18 days for resurfacing arthroplasties and 5.45 days for total hip replacements. Neither of these differences was significant. The male-female ratio in the two groups was significantly different. However, when the subgroups of the same gender were compared, the results were essentially the same: no statistical difference was found for the post-operative pain, speed of rehabilitation or length of hospital stay. We conclude that resurfacing arthroplasty has no evidence of an advantage over total hip replacement in the speed of post-operative rehabilitation.

Purpose: The report of a case o f a patient, who underwent a total hip arthroplasty and sustained cerebral hemorrhage due to low molecular weight heparin.

Case report: A 46-years-old woman had a total hip replacement due to secondary osteoarthritis after a congenital hip dislocation. She had a free medical record. Treatment with LMWH started the day of the surgery. The patient was dismissed from the hospital the sixth postoperative day, being well, and came back the ninth postoperative day, complaining of hypertension, headache and motor disturbances of her left upper limb. Neurological examination did not revealed any particular findings except reduced strength of her left upper limb. A brain CT scanning showed no significant findings, while her blood platelet count was126000 while immediately postoperatively was 180000 and preoperatively 220000. The following day the patient established a paresis of her left arm and the platelet count fell to 35000, while a new CT scan, revealed small hemorrhages in both parietal cortexes of the brain. LMWH was discontinued. The patient deceased the 11th postoperative day.

Conclusion: Heparin Induced Thrombocytopenia type II and hemorrhage due to LMWH is very rare but should be bared in mind from the orthopaedic surgeon who uses LMWH for DVT prophylaxis. Clinical suspicion mandates immediate discontinuation of the agent and consideration of an alternative anticoagulation therapy along with general support of the patient.

Purpose: The correlation of surgical wounds for total hip and knee replacements with the presentation or recurrence of skin disorders.

Materials-method: In 9 patients, 5 men and 4 women, operated for total knee replacement and 1 patient, a female, operated for total hip replacement, skin disorders appeared around their surgical wounds. The female patient with the THR sustained a herpes zoster in the operated buttock 8 months after surgery. 1 patient with leuke had an exaltation of symptoms the wounds of both operated knees. 6 patients, 2 men and 4 women, had increased growth of hair on both sides of the wound some months after the TKR, in contrast with the rest of their skin. 1 patient with psoriasis had increased local symptoms after a TKR compared with the non-operated side. Finally, 1 patient, 25 days after a TKR, sustained an exanthema around his wound.

Conclusion: Total joint replacement may rarely be the cause for the presentation or recurrence of skin disorders around the surgical wounds.

The aim of this study is the presentation of the results in 48 cases of revision THA with excessive proximal bone loss with the use of the Wagner cementless femoral stem

The bone loss classified with the AAOS system for proximal femoral bone deficiency in type I (17 patients), II (27 patients), and III (4 patients). We used the titanium alloy Wagner stem trying to achieve primary distal stabilisation because of its conical shape and its longitudinal ridges while we expected secondary proximal stabilization due to the osseointegration properties of the material. We didn’t use grafts.

The mean follow- up is 9, 6 years. The results are very satisfactory to excellent with marked pain relief, improvement of the walking ability and excessive bone restoration in the proximal part of the femur.

7 of the patients had a symptomless stem subsidence up to 16mm the first year with subsequent stabilization thereafter. One of the patients required a new revision the 7th postoperative year due to stem’s fracture in its distal part.

We conclude that the Wagner stem in these difficult THA revisions offers firm primary distal fixation, impressive proximal bone regeneration and satisfactory clinical outcomes without using grafts.