Introduction

Problematic bone defects are encountered regularly in orthopaedic practice particularly in fracture non-union, revision hip and knee arthroplasty, following bone tumour excision and in spinal fusion surgery. At present the optimal source of graft to ‘fill’ these defects is autologous bone but this has significant drawbacks including harvest site morbidity and limited quantities.

Bone marrow has been proposed as the main source of osteogenic stem cells for the tissue-engineered cell therapy approach to bone defect management. Such cells constitute a minute proportion of the total marrow cell population and their isolation and expansion is a time consuming and expensive strategy.

In this study we investigated human bone marrow stem cells as a potential treatment of bone defect by looking at variability in patient osteogenic cell populations as a function of patient differences. We produced a model to predict which patients would be more suited to cell based therapies and propose possible methods for improving the quality of grafts.

Purpose

To study the initial presentation and subsequent investigation and management of acute knee dislocations at a regional trauma centre.

Introduction: Intracapsular femoral neck fractures in adults under 65 years old are associated with significant complications such as avascular necrosis of the femoral head and non-union. Timing of surgery remains controversial, with some studies suggesting that early surgical fixation reduces the rate of these complications. Presently the policy in this Fracture Unit remains early fixation (target less than twelve hours). The purpose of this study is to determine if this twelve hour target is being achieved and if not, where the delays are occurring.

Methods: A retrospective case-note and data analysis was performed on all patients aged under 65 who underwent internal fixation of displaced intracapsular femoral neck fractures (Garden III/IV) between 31/12/06 and 31/12/07. The following data was collected; time of injury to presentation at health service, time from presentation at health service to admission at treating hospital, time of admission at treating hospital to time of surgery and overall time from injury to surgery. The main causes of delay were also determined.

Results: In the one year period, there were 37 young adults with displaced intracapsular femoral neck fractures, with a mean age of 52.57 years. There were 23 females (62.2%) and 14 males (37.8%).

We also present the reasons for delay at each stage including transfer delays, medical delays and limited emergency theatre availability.

Discussion: Early operative fixation of young femoral neck fractures remains controversial. In this unit where it is advocated, the median time from injury to fixation is 22.18 hours. By reducing transfer times, increasing emergency theatre availability and improving efficiency of patient preparation for theatre at ward level, the twelve hour targets will be much more attainable.

Introduction: Intracapsular femoral neck fractures in adults under 65 years old are associated with significant complications such as avascular necrosis of the femoral head and non-union. Timing of surgery remains controversial, with some studies suggesting that early surgical fixation reduces the rate of these complications. Presently the policy in this Fracture Unit remains early fixation (target less than twelve hours). The purpose of this study is to determine if this twelve hour target is being achieved and if not, where the delays are occurring.

Methods: A retrospective case-note and data analysis was performed on all patients aged under 65 who underwent internal fixation of displaced intracapsular femoral neck fractures (Garden III/IV) between 31/12/06 and 31/12/07. The following data was collected; time of injury to presentation at health service, time from presentation at health service to admission at treating hospital, time of admission at treating hospital to time of surgery and overall time from injury to surgery. The main causes of delay were also determined.

Results: In the one year period, there were 37 young adults with displaced intracapsular femoral neck fractures, with a mean age of 52.57 years. There were 23 females (62.2%) and 14 males (37.8%).

We also present the reasons for delay at each stage including transfer delays, medical delays and limited emergency theatre availability.

Discussion: Early operative fixation of young femoral neck fractures remains controversial. In this unit where it is advocated, the median time from injury to fixation is 22.18 hours. By reducing transfer times, increasing emergency theatre availability and improving efficiency of patient preparation for theatre at ward level, the twelve hour targets will be much more attainable.

Thrombin related peptide (TP 508) is a 23 amino-acid synthetic peptide that mimics a portion of the receptor-binding domain of the human thrombin molecule.

Thrombin triggers both proteolytic activated receptors and non proteolytic activated receptors to bring about a mixture of responses ranging from tissue breakdown and clot formation, to new vessel formation and tissue repair. TP 508 stimulates only the non proteolytic activated receptors, and this initiates repair and angiogenesis but not clot formation or tissue breakdown Previous studies have shown that TP508 can stimulate repair in the dermal and musculoskeletal tissues by promoting angiogenesis and enhancing the proliferation and migration of cells.

High energy fractures are associated with a delay in healing. We hypothesized that high energy fracture healing would be improved with the use of TP508, and that the dose and site of application would have importance.

Methods: 80 CD 1 Mice were randomised into four groups; all underwent a high energy quadriceps muscle crush and a femoral fracture on the left hind limb. In each case the fracture was reduced and held with an external fixator. At the time of operation Group I received a dose of 100ìg TP 508 into the fracture, Group II 100ìg into the surrounding damaged soft tissue, Group III a dose of 10ìg into the fracture, and group IV (the control group) received PBS carrier into the fracture.

24 animals were sacrificed on day 21 and the remaining 56 mice on day 35. Of the 35 day old animals 8 in each group had both femora harvested and the biomechanical properties were tested using the 3-point bending technique. Specimens from the 21 day old animals and remaining 35 day old animals were used for histological analysis.

All 80 animals had digital radiographs taken each week. Using image analysis software five pixel density graphs were generated across each fracture gap. A validated semi quantitative analysis was used to score each graph and the total accumulated for each radiograph. The width of the fracture calus was measured and expressed as a ratio of the femur diameter.

Results: Mechanical testing showed significantly greater stiffness in group I when compared to control (p < 0.05), and a dose dependent trend of increasing strength.

Radiographic analysis showed greater healing of fracture and callus formation in Group I compared to Groups II, III, and IV, at both three and five weeks post-fracture (P< 0.05).

Histological analysis showed an increase in bone formation in group I compared to the other groups.

Conclusion: This data from this model, suggests that TP508 enhances healing in high energy fractures. The results also suggest that the effects of TP508 are dose dependant, and are greater when delivered into the fracture site.

Purpose: There are numerous papers from specialist arthroplasty centres outlining results of total knee arthroplasties but little information from outside these major centres. We carried out a review of a fixed bearing total condylar knee replacement used in Dunedin by a variety of surgeons for over 10 years.

Method: All patients who received a Duracon/PCA fixed bearing total knee replacement between 1992 and 1996 were assessed clinically, fluoroscopically and completed an SF12, WOMAC and IKSS questionnaire.

Results: At a mean 9.7 (8–12) years follow up, 126 (69.6%) patients were available for review and 46 (25%) were deceased. The average age was 72 years (52–88) and the primary diagnosis was osteoarthritis in 95% of the cases. There were 34% Charnley Grade A, 37% Grade B and 29% Grade C respectively.

The average IKS Knee score was 72 (23–97) and the functional score was 68 (0–100) with 74% experiencing none or only mild pain. The SF12 assessment revealed a mean physical score of 55 (14–99). Ninety per cent of patients were satisfied with their knee and 89% would have the operation again if required.

There was one operative death (PE), one deep infection, 3 PE’s, 3 DVT’s and 5 superficial infections. An MUA was required in 9 cases.

Eight knees were revised. Using ‘all revisions’ as an end point. The survival rate was 95.3% at 10 years.

Conclusion: These results suggest that knee replacements carried out outside specialist arthroplasty centres perform very well with a survival rate of the implant of 95% at 10 years.

Aim: To assess the functional and radiological outcome of AO wrist Arthrodesis using the AO wrist fusion plate.

Method: An 8 year, independent, retrospective, radiological and functional review was performed using The DASH (Disabilities of the Arm, Shoulder and Hand questionnaire) and the Buck-Gramcko/Lohmann outcome scores.

Results: Twenty-eight patients were reviewed. The two scoring systems correlated consistently in regards to the functional outcome. However, patients with systemic disease experienced problems completing the DASH questionnaire. Mono-articular arthritis was associated with an excellent/good outcome in 95% of cases. Results for patients with systemic disease were markedly worse. There was one case of plate breakage associated with a delayed union of the second MCP joint. There was a 100% union rate, no significant post-operative infections and no tendon ruptures.

Conclusion: The short to mid term clinical outcomes for the AO wrist fusion plate are encouraging and its use can be recommended in a variety of wrist pathologies.

There are numerous papers from specialist arthroplasty centres outlining results of total knee replacement. This review was performed as there is little information on results in general orthopaedic centres. All patients received a Duracon/PCA replacement between 1992 and 1996. Patients were assessed clinically, fluoroscopically and completed SF12, WOMAC and IKSS questionnaires. At a mean of 6.7 (5–9) years follow up 93 (78%) were available for review. The average age was 70 years (52–88) with 58% being male. The primary diagnosis was osteoarthritis in 94.3%, with 41 %, 38% and 21 % being Charnley grades A, B and C respectively.

The average IKS knee score was 71.4 (23–96) and functional score 70 (0–100), with 72.7% experiencing none or only mild pain. The SF12 assessment revealed a mean physical score of 38 (14–63) and mental score of 53 (25–67). There were 88.6% of patients satisfied with their knee and 92% would have the operation again if required. There were no deep infections or PE’s but there were 7 superficial infections and 2 DVT’s. A MUA was required in 8 patients. One patient retains a radiologically loose prosthesis at 8 years but had mild pain with stairs only, a WOMAC functional score of 85 and was happy. There was a best-case survival of 94.4% at 5 years. There were 5 knees revised in 5 patients and no revisions of the deceased patients, all surviving greater than 5 years from surgery. These results suggest that those in general orthopaedic centres are a little less reliable than those in specialist centres. However they are acceptable and patient satisfaction remains high.