Principles of managing Vancouver type B periprosthetic fractures around cemented polished tapered femoral stems.

The management of periprosthetic fractures around total hip replacements is a complex and challenging problem. Getting it right first time is an important factor in reducing the morbidity, mortality and financial burden associated with these injuries. Understanding and applying the basic principles of fracture management helps increase the chance of successful treatment. Based on these principles, we suggest a treatment algorithm for managing periprosthetic fractures around polished tapered femoral stems.

Revision hip arthroplasty using impacted cancellous bone and cement: a long-term follow-up study.

Acetabular bone deficiency is one of the many challenging problems encountered in revision hip arthroplasty. A variety of surgical options and techniques are available including impaction bone grafting. We present our long-term experience of 68 consecutive cups in 64 patients, using impacted cancellous bone grafting with bone cement. With a mean follow-up of 10.5 year (IQR 7.5-12.9) after revision surgery, three implants had undergone further revision. Three patients had subsequent femoral peri-prosthetic fractures, and none of these three required further acetabular revision. Survival of the acetabular components was 95.5 % for all causes and 100 % for aseptic loosening as the end point, with a further four patients showing radiographic, but asymptomatic loosening. A significant correlation was found between previous revision and re-revision (early failure) (p = 0.01) as well as progression of lytic lesion and re-revision (p = 0.01). The median Harris hip score at final follow-up was 79.5 (IQR 67.9-80.4). The use of impacted morcellised allograft bone with a cemented cup is an effective technique to achieve longevity and restoration of bone stock in acetabular revision arthroplasty. Our series has shown good clinical and radiological outcome with survivorship of the prosthesis exceeding 95 % at 10 years.

Strategies for fixation of periprosthetic fragility fractures of the neck of femur below a well-functioning hip resurfacing arthroplasty: A case-series.

Introduction: Metal-on-metal Hip Resurfacing (HR) was performed in many young individuals as it conserved bone stock and had low wear rates, before it became less popular due to the detection of Adverse Reactions to Metal Debris. As such, many patients in the community have well-functioning HRs and as they age, the incidence of fragility fractures of the neck of femur around the existing implant is expected to increase. These fractures are amenable to surgical fixation as adequate bone stock remains in the head of the femur and the implants are well fixed. Case-series: We present a series of six cases which were treated by fixation using locked plates (3), dynamic hip screws (2) and cephalo-medullary nail (1). Four cases achieved clinical and radiographic union with good function. One case had a delayed union, though union was finally achieved at 23 months. One case had an early failure necessitating revision to a Total Hip Replacement after 6 weeks. Discussion: We highlight the geometrical principles of placing fixation devices under an HR femoral component. We have also conducted a literature search and present details of all case reports to date. Conclusion: Fragility per-trochanteric fractures under a well-fixed HR with good baseline function are amenable to fixation using a variety of methods including large screw devices that are commonly used in this location. Locked plates including variable angle locking designs should be kept available if needed.

The Bicontact cementless primary total hip arthroplasty: long-term results.

We report on a prospective series of 201 primary uncemented total hip arthroplasties with a Bicontact prosthesis at a mean follow-up of 12.9 years. The mean Harris hip score improved from 41 before surgery to 89 at final follow-up. Two femoral stems, one each for infection and fracture, and 12 cups were revised. The mean number of years to revision post-primary surgery was 8.7 years (six months to 16 years). The cumulative survival of the prosthesis was 95.42% for any cause at ten years and 93.57% at 12 years. Survivorship for aseptic loosening of the femoral stem was 100%. In our series, the Bicontact uncemented total hip arthroplasty stem without hydroxyapatite coating showed excellent survival and the cup survival was comparable to other leading series.

Aspirin monotherapy is a suitable standard thromboprophylactic agent following total hip arthroplasty.

INTRODUCTION: Aspirin is increasingly recognised as an efficacious thromboprophylactic agent with a superior safety profile compared to alternatives. Following our institution's previously published experience we implemented a risk-stratified protocol utilising aspirin as standard. We now present retrospective review of standard use of aspirin on fatal pulmonary embolism, all-cause mortality, and venous thromboembolism (VTE) following total hip arthroplasty (THA). METHODS: A consecutive series of elective THAs was identified. Prospectively maintained databases were analysed to yield demographic data and identify deaths or readmission data. Patients who died within 90 postoperative days underwent review of the complete medical record. RESULTS: 4204 THAs were included in the study cohort. VTE prophylaxis prescription was available in 3805. 2560 received aspirin (67.3%), 1049 enoxaparin (27.6%) and 193 warfarin (5.1%); there were no differences in 90-day all-cause mortality (p = 0.780) or VTE (p = 1) between groups. CONCLUSION: Our large series continues to demonstrate that aspirin for thromboprophylaxis following THA is effective in risk-stratified patients. Furthermore, we demonstrate that introduction of a departmental protocol establishing aspirin as standard practice was not associated with increased mortality or incidence of thromboembolism. Taken in conjunction with our previous cohort our series encompasses 11,420 consecutive THAs. There has been a single death following fatal PE in the aspirin group (0.02%) compared to 5 in the LMWH group (0.2%) and 1 in the warfarin group (0.06%). We join calls for large-scale randomised controlled trials to elucidate the place of aspirin in VTE prevention following hip arthroplasty.

Computed tomography to detect accessory spleens before laparoscopic splenectomy: is it necessary?

BACKGROUND: Some one-fifth of patients may have accessory spleens (AcS) and require their removal at the time of splenectomy to achieve and maintain hematological response. The purpose of this study was to evaluate the benefit of computed tomography (CT) in patients undergoing laparoscopic splenectomy (LS). METHODS: All patients who required splenectomy were offered LS and underwent preoperative contrast-enhanced CT scan to detect and locate AcS. The surgeon was not blinded to the result of the CT scan. Patients were followed up to determine if there was recurrent disease. RESULTS: Between 2000 and 2007, 58 consecutive patients (31 men) were referred for splenectomy and all underwent LS. Preoperative CT scan detected 11 AcS in 11 patients (19%), of which 9 were confirmed during LS; the remaining 2 patients suffered with ITP preoperatively and had a good hematologic response to LS. At LS, 14 AcS were found in 13 patients (22%), of which 4 patients had negative preoperative CT scan; those additional AcS were readily found and were located close to the lower pole or hilum of the spleen. All removed AcS were confirmed histologically. In one patient who had LS and removal of AcS for ITP a further AcS within the tail of the pancreas was detected 1 year postoperatively on CT after thrombocytopenia relapsed. The sensitivity and specificity of CT scan for the detection of AcS were 60% and 95.6%, and the corresponding values for laparoscopy were 93.3% and 100%, respectively. Pairwise comparison of the ROC curves identified laparoscopy to be associated with a significantly higher area under the curve compared with CT scan (0.967 vs. 0.673; P = 0.004). CONCLUSIONS: Accessory spleens can be readily detected at laparoscopy in the vicinity of the spleen; preoperative CT scan for their detection and localization may not be necessary.

Review of evolution of tunnel position in anterior cruciate ligament reconstruction.

Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established.

Surgical management of a completely avulsed adductor longus muscle in a professional equestrian rider.

Avulsion injuries of the adductor longus muscle tendon are rare and a challenge to manage especially in athletes. There has been little published literature on the outcome of conservative and operative treatment for these injuries. We report the first case of an acute adductor longus avulsion injury which was surgically repaired in a professional equestrian rider. Return to full preinjury function was achieved at 3 months with surgical repair using 3 suture anchors.

Nontraumatic fracture of the femoral condylar prosthesis in a total knee arthroplasty leading to mechanical failure.

This paper reports a case of fatigue fracture of the femoral component in a cruciate-retaining cemented total knee arthroplasty (TKA). A 64-year-old man had undergone a primary TKA for osteoarthritis 10 years previously at another institution using the PFC-Sigma prosthesis. The patient recovered fully and was back to his regular activities. He presented with a history of sudden onset pain and locking of the left knee since the preceding three months. There was no history of trauma, and the patient was mobilizing with difficulty using crutches. Radiographs revealed fracture of the posterior condyle of the femoral prosthesis. Revision surgery was performed as an elective procedure revealing the broken prosthesis. The TC3RP-PFC revision prosthesis was used with a medial parapatellar approach. The patient recovered fully without any squeal. Mechanical failure of the knee arthroplasty prosthesis is rare, and nontraumatic fracture of the femoral metallic component has not been reported before.

Finite element investigation of the effect of a bifid arch on loading of the vertebral isthmus.

BACKGROUND: The biomechanical effect of a bifid arch as seen in spina bifida occulta and following a midline laminectomy is poorly understood. PURPOSE: To test the hypothesis that fatigue failure limits will be exceeded in the case of a bifid arch, but not in the intact case, when the segment is subjected to complex loading corresponding to normal sporting activities. STUDY DESIGN: Finite element analysis. METHODS: Finite element model of an intact L4-S1 human lumbar motion segment including ligaments was used. A section of the L5 vertebral arch and spinous process was removed to create the model with a midline defect. The models were loaded axially to 1 kN and then combined with axial rotation of 3°. Bilateral stresses, alternating stresses, and shear fatigue failure on both models were assessed and compared. RESULTS: Under 1 kN axial load, the von Mises stresses observed in midline defect case and in the intact case were very similar (differences <5 MPa) having a maximum at the ventral end of the isthmus that decreases monotonically to the dorsal end. However, under 1 kN axial load and rotation, the maximum von Mises stresses observed in the ipsilateral L5 isthmus in the midline defect case (31 MPa) was much higher than the intact case (24.2 MPa), indicating a lack of load sharing across the vertebral arch in the midline defect case. When assessing the equivalent alternating shear stress amplitude, this was found to be 22.6 MPa for the midline defect case and 13.6 MPa for the intact case. From this, it is estimated that shear fatigue failure will occur in less than 70,000 cycles, under repetitive axial load and rotation conditions in the midline defect case, whereas for the intact case, fatigue failure will occur only after more than 10 million cycles. CONCLUSIONS: A bifid arch predisposes the isthmus to early fatigue fracture by generating increased stresses across the inferior isthmus of the inferior articular process, specifically in combined axial rotation and anteroposterior shear.

Fixed flexion deformity following total knee arthroplasty. A prospective study of the natural history.

INTRODUCTION: Stiffness following total knee arthroplasty (TKA) is a disabling problem resulting in pain and reduced function. OBJECTIVE: The aim of our study was to evaluate the natural course of fixed flexion deformity (FFD ) following primary total knee arthroplasty. METHODS: Prospective review of 1626 patients undergoing primary TKA from 2001 to 2006 with a minimum of 4 year follow up. Demographic data included post-operative range of motion; type of prosthesis used, treatment modalities for stiffness and the final range of motion were recorded. FFD was defined as class 1(5-15 degrees) and Class 2 (> 15 degrees). Patients with a pre-operative FFD of >15, infection, stiffness treated with manipulation or revision surgery were excluded from the study. RESULTS: Of the 1626 patients evaluated, 170 (10.5%) presented with a FFD. 18 patients were excluded from the study and 16 were lost to follow up. 124 (91.2%) were class 1 and 12 (8.8%) were class 2. FFD improved from a mean of 8.8 degrees to 0.4 degrees (p<0.0001) in 11.4 months. In 94.1% patients the FFD completely resolved (i.e. < 5 degrees) at a mean of 10.8 months (p<0.0001). In the remaining 5.9% of patients, FFD improved from a mean of 16.4 to 6.9 degrees at a mean follow up of 21.5 months (p<0.0001). CONCLUSION: A gradual improvement in the FFD can be expected up to 2 years and a small residual flexion contracture does not cause functional deficit. LEVEL OF EVIDENCE: Prospective cohort study, level 3.