Objectives

Subtotal or total meniscectomy in the medial or lateral compartment of the knee results in a high risk of future osteoarthritis. Meniscal allograft transplantation has been performed for over thirty years with the scientifically plausible hypothesis that it functions in a similar way to a native meniscus. It is thought that a meniscal allograft transplant has a chondroprotective effect, reducing symptoms and the long-term risk of osteoarthritis. However, this hypothesis has never been tested in a high-quality study on human participants. This study aims to address this shortfall by performing a pilot randomised controlled trial within the context of a comprehensive cohort study design.

Aim

Debate remains over the optimal treatment for severe unstable SCFE. AVN is the principle problem; current thinking suggests this can be minimized by emergent reduction and fixation within 24 hours. If emergent treatment is not possible, open osteotomy with a variable delay of 10–21 days has been advocated. We present our experience of delayed intracapsular cuneiform osteotomy (ICO)

The aim of this retrospective study was to review the outcome of patients treated with Fassier-Duval (FD) rods and highlight some of the complications found during treatment.

Between April 2006 and August 2010 we inserted 24 FD rods in 13 patients. 17 rods for osteogenesis imperfecta (OI), 2 for fractures and deformity associated with cerebral palsy, 1 for fracture associated with muscular dystrophy, 1 for fibrous dysplasia and 3 for centralisation of single bone forearms.

In the upper limb one patient required revision for proximal migration of the male component and another patient is waiting for revision for the same problem.

In the lower limb, a tibial nail was revised because of proximal migration of the male component. A femoral nail was adjusted because of loss of the proximal fixation. One of the OI patients fell, fractured the femur and bent a femoral nail. This awaits revision at a later date. A second OI patient fell on 2 separate occasions bending both a tibial and a femoral nail respectively. These were both revised to trigen intramedullary nails.

In all the other cases there were no complications.

In summary the Fassier Duval system provides a versatile way of providing intramedullary stabilisation for growing bones through a single entry point. However in our experience we have a 33% complication rate most notably bending of the rods. We advocate careful patient selection and using as high a diameter nail as is feasible.

Opinions about the treatment of Perthes' disease vary widely. However there is no disagreement about the need for containment during fragmentation stage to create an optimum biomechanical environment for remodelling of femoral head. Types of containment may vary. Younger children do well irrespective of the method of containment. Older children usually require surgical containment. The present study was aimed at evaluating the results of different methods of surgical containment in different age group and identifying specific factors that alter the final outcome and prognosis.

107 cases were reviewed retrospectively. 21 cases were excluded due to lack of records. 86 hips were available for clinical and radiological evaluation. 31 patients were under 7 years and required Varus osteotomy (VO). 55 patients were above 7 years. VO was performed in 30 hips and Shelf containment was done in 25. Case notes were reviewed for demographic details, surgical details and clinic letters. Radiographs were reviewed for Herring's grading, Stulberg staging, containment indices, centre edge angle, lateral pillar height, Mose index, neck shaft angle and shelf width.

In all patients, there was an improvement in pre-operative symptoms and summated range of motion, especially abduction. Good functional and radiological outcome was seen in age group < 7 years. In older children, outcome was good to satisfactory with Herring grade B. Stulberg grading worsened with advancing age and Herring grade C, irrespective of the method of containment. Persistence of varus neck shaft angle and trochanteric overgrowth were significant problems with VO. Although all containment indices improved with Shelf group, Stulberg grading remained poor in most patients.

The lateral pillar classification and age strongly correlate with final outcome. Herring group C had the least favourable result. Stulberg staging remained poor in older children irrespective of the method of containment.

Purpose: Severe fractures damage blood vessels and disrupt circulation at the fracture site resulting in an increased risk of poor fracture healing. Endothelial progenitor cells (EPCs) are bone-marrow derived cells with the ability to differentiate into endothelial cells and contribute to neovascularization and re-endothelialization after tissue injury and ischemia. We have previously reported that EPC therapy resulted in improved radiographic healing and histological blood vessel formation in a rat fracture model. The purpose of this study was to further quantify the effects of EPC therapy with microCT and biomechanical analyses.

Method: Five-millimeter segmental defects were created and stabilized in the femora of 14 fisher 344 rats. The treatment group (n=7) received 1x106 EPCs within gelfoam locally at the area of the bone defect and control animals (n=7) received only saline-gelfoam with no cells. The formation and healing of bone after 10 weeks were asessed by radiographic, micro-CT and biomechanical analyses.

Results: Radiographically all the animals in EPC-treated group healed with bridging callus formation, whereas control group animals demonstrated radiographic non-union. Micro-CT assessment demonstrated significantly improved parameters of bone volume (35.34 to 20.68 mm³, p=0.000), bone volume density (0.24 to 0.13%, p=0.001), connectivity density (25.13 to 6.15%, p=0.030), trabecular number (1.14 to 0.51 1/mm, p=0.000), trabecular thickness (0.21 to 0.26 mm, p=0.011), trabecular spacing (0.71 to 1.88 mm, p=0.002), bone surface area (335.85 to 159.43mm, p=0.000), and bone surface to bone volume ratio (9.43 to 7.82 1/mm, p=0.013) in the defect site for the EPC group versus the control group respectively. Biomechanical testing showed that the EPC treatment group had a significantly higher torsional strength compared with the control group (EPC=164.6±27.9 Nmm, Control=29.5±3.8 Nmm; p value = 0.000). Similarly, the EPC treated fractures demonstrated significantly higher torsional stiffness versus controls (EPC=30.3±5.0 Nmm/ deg, Control=0.9±0.1 Nmm/deg; p value = 0.000). When biomechanically compared to contralateral intact limbs, the EPC treated limbs had similar torsional stiffness (p=0.996), but significantly lower torsional strength (p=0.000) and smaller angle of twist (p=0.002).

Conclusion: These results suggest that local EPC therapy significantly enhances fracture healing in an animal model. The biomechanical results show that control animals develop a mechanically unstable non-union. In contrast, EPC therapy results in fracture healing that restores the biomechanical properties of the fractured bone closer to that of intact bone.

Purpose: The distribution of weight bearing area within the acetabulum is of importance in addressing trauma to the acetabulum, hip joint deformities and causes of osteoarthritis. According to Wolf’s law, bone density can indicate loading patterns experienced. The objective of this study was to characterize distributions of acetabular bone density patterns by regions in the normal population.

Method: CT scans of 22 subjects, mean age 70.6 with no evidence to hip joint pathologies were analysed. Bone density distribution maps were generated within AmiraDEV4.1 image analysis software using custom written plugins (Visage Imaging, Carlsbad, USA). Acetabular cup surfaces were semi-automatically segmented from the reconstructed CT volumes with an atlas-based approach. The acetabular cups were expanded 2.5 mm into the acetabular bone, and surface bone densities were calculated as the average bone density within ±2.5mm. The distribution maps were analysed using zones to spatially classify areas of high and low bone density in a healthy population. The acetabular cups were aligned using the acetabular rim plane that was landmarked, and by rotating the cups, such that a 900 abduction angle and a 00 anteversion angle were achieved. The grid used was divided to quadrants, and subdivided into radial thirds of the average rim radius. The correspondence of left and right density maps was investigated by comparing the average bone density in corresponding zones and across the population.

Results: High bone densities were found around the roof of the acetabulum aligning with the femoral mechanical axis during standing. The highest average bone density were found to be the superior and posterior walls of the acetabulum, corresponding to regions 8, 9, and 12 compared to other regions of the acetabuli (P< 0.01). A strong correlation was found between left and right sides within subjects (R=0.91, P< 0.05); and weaker correlation was also found for overall average bone density, (R=0.77, P< 0.05).

Conclusion: The location of the zones with the highest average bone density agrees with cadaveral studies of the maximum contact stress in the acetabulum (zones 9 and 12). [1,2]. It may explain why trauma to these areas carries a higher risk for early arthritic changes.

Introduction: We assessed the correlation between the International Prostate Symptom Score (IPSS), patient age and incidence of post-operative catheterisation for retention in patients undergoing total hip replacement.

Methods And Results: 140 patients, 60 male and 80 female, admitted for total hip replacements between August 2005 and March 2006 were included. Pre-operatively patients were scored by the IPSS (0–35) according to the severity of their urinary symptoms. Patients were categorised into three symptom groups (mild, moderate and severe based on scores of 0–7, 8–18 and > 18 respectively) and four age groups (< 50, 51–60, 61–70 and > 70 years). All patients with post-operatively urinary retention were catheterised per urethra.

Results: 8 (13.3%) males and 7 (8.8%) females were catheterised post-operatively. The average IPSS value in non-catheterised males and females were 8.9 and 9.5 respectively whereas in catheterised males and females were 21 and 19 respectively. 75% of catheterised males had an IPSS > 18. 85.7 % of catheterised females had an IPSS > 18. Statistical analysis showed significant association between high IPSS (> 18) and catheterisation risk in both males (chi square - p< 0.001, sensitivity- 0.75, specificity- 0.92, negative predictive value (NPV) - 0.96) and females (chi square - p< 0.001, sensitivity- 0.86, specificity- 0.90, NPV- 0.99). There was no significant relation between age and incidence of catheterisation.

Discussion: IPSS is a widely accepted, simple and easy to use tool to predict patients at risk of post-op catheterisation. It is a simple pre-assessment tool even in female patients. Patients with IPSS > 18 are most at risk of post-op retention.

Introduction: Fractures of the femoral stem component in total hip Arthroplasty have been a well documented complication. The incidence over recent years has decreased due to improvements in surgical technique and implant design and manufacture.

Methods/Results: We report two cases of femoral stem fracture. Both occurred in CDH stems from the C-stem system (Depuy International, Leeds, UK). These are the first reported fractures in this stem. Both patients were women weighing 83kgs and 98kgs at the time of fracture giving them BMI’s of 31 and 41 respectively. In both cases the BMI had increased since the time of operation.

Discussion: The design of the CDH stem is fundamentally different from the rest of the standard stems with absence of the medial strut. In addition to this factor, both stems fractured through the insertion hole which acted as a stress raiser. Finally both patients BMI’s were above 25. At the time of operation no weight limit was imposed on this prosthesis.

We conclude that if possible, a standard C-stem should be inserted but if a CDH stem is used attention to patients’ weight is paramount.

Introduction: The Opera Acetabular cup (Smith and nephew) was designed in North Manchester General and has been in use since 1997. The initial results were with multiple surgeons, different approaches and 2 different stems. We report the early results of the opera cup in primary hip replacements using the C-Stem.

Methods: This is a prospective radiological follow up of patients operated on between June 2000 and November 2004. 202 consecutive primary hip replacements were carried out using the Opera cup and a standard C-stem. All operations were performed by a single surgeon using the posterior approach. Initial and annual x-rays were studied and the following measurements taken: cup angle; radiolucent lines in the bone-cement interface of the acetabulum; heterotopic ossification; radiolucent lines or osteolysis in the femoral component and stem orientation.

Results: Full data is available in 166 hips performed on 149 patients. Average follow up is 37 months (12–65). 84 patients were female and 65 male. There were 56 left hip replacements, 76 right hip replacements and 17 were bilateral. 162 hips had an elite head whereas 4 had a ceramic head. Average cup angle was 44.6 degrees. 20 Cups had 0.5mm lucency in zone 1 of the acetabulum and 1 cup had 1mm lucency in zone 1. None were progressive. 14 patients had grade 1 heterotopic ossification 3 patients had grade 2. 1 stem was in valgus and 13 stems were in varus.

Complications were 1 calcar fracture and 1 greater trochanter fracture (both of which required circlage wires). There was also 1 temporary femoral nerve palsy which resolved in 3 months. There were no fatal PE’s, deep infections or dislocations. No hips have required revision.

Discussion: We conclude that in the short term the Opera cup is performing to the standard required by NICE.

Introduction: The C-stem total hip replacement system was devised in Wrightington in 1993 and represented the first triple tapered stem. There is little literature about the follow up outside of Wrightington and therefore we present our data on the C-Stem at a district general hospital.

Methods: This is a prospective radiological follow up of patients between March 2000 and November 2004, 250 primary hips were performed by a single surgeon using a posterior approach. Cemented all polyethylene cups were used. Initial and annual x-rays were reviewed and the following measurements were recorded: cup angle; radiolucent lines in the bone-cement interface of the acetabulum; heterotopic ossification; stem subsidence, radiolucent lines or osteolysis in the femoral component and stem orientation.

Results: Data is available on 206 hips performed on 185 patients. 107 patients were female and 78 patients were male. 72 were left sided, 92 were right sided and 21 were bilateral. The average age was 66yrs (25–89). Average follow up was 41 months (12–68). The average cup angle was 44.7 degrees. 24 patients had 0.5 mm lucencies in zone 1 of the acetabulum and 1 patient had 1mm lucency in zone 1. No lucencies were progressive. There were no lucencies in any of Gruens’s zones. 18 patients had Grade 1 heterotopic ossification, 2 Grade 2 and 1 Grade 4. 17 stems were in varus and 1 stem in valgus. Average stem subsidence was 0.83mm.

Complications were 1 fractured greater trochanter wired intra-operatively and 1 femoral nerve palsy which resolved in 3 months. There were no PE’s, dislocations or deep infections. No hip replacement has required revision.

Discussion: We conclude that at a maximum follow up of 5.5 years the C-Stem is performing to standards required by NICE and is on course to achieve the benchmark of 10% revision at 10 years.