Simulated learning is increasingly prevalent in many surgical training programs as medical education moves towards competency based curricula. In orthopaedic surgery, developmental dysplasia of the hip is a commonly treated diagnosis where the standard of care in patients less than six months of age is an orthotic device such as the Pavlik Harness. However, despite widespread use of the Pavlik Harness and the potential complications that may arise from inappropriate application, no formal educational methods exist.

A video and model based simulated learning module for Pavlik Harness application was developed. Two novice groups (residents and allied health professionals) were exposed to the module and at pre-intervention, post-intervention and retention testing were evaluated on their ability to apply a Pavlik Harness to the model. Evaluations were completed using a previously validated Objective Structured Assessment of Technical Skill (OSATS) and a Global Rating Scale (GRS) specific to Pavlik Harness application. A control group who did not undergo the module was also evaluated at two time points to determine if exposure to the Pavlik Harness alone would affect ability. All groups were compared to a group of clinical experts who were used as a competency benchmark. Statistical analysis of skill acquisition and retention was conducted using t-tests and ANOVA.

Exposure to the learning module improved resident and allied health professionals' competency in applying a Pavlik Harness (p<0.05) to the level of expert clinicians and this level of competency was retained one month after exposure to the module. Control subjects who were not exposed to the module did not improve nor did they achieve competency.

The simulated learning module has been shown to be an effective tool for teaching the application of a Pavlik Harness and learners demonstrated retainable skills post intervention. This learning module will form the cornerstone of formal teaching for Pavlik Harness application in developmental dysplasia of the hip.

Background

Primary dislocation of the patella is a common acute knee disorder in children, adolescents and young adults. While primary dislocation of the patella has traditionally been treated non-operatively, primary operative repair of the medial patella-stabilizing soft tissues has been popularized more recently and thought to reduce the risk of dislocation. However, several studies have shown substantial rates of redislocation with longer follow-up time, irrespective of treatment. The purpose of this systematic review was to compare operative and non-operative treatment for primary dislocation of the patella, regarding redislocation rates and symptoms.

A prospective review was undertaken examining referrals from A& E to fracture clinic with the objective to examine diagnosis and timing of fracture clinic appointment made by A& E with that suggested by an Orthopaedic Specialist Registrar (SpR).

Over a 4 week period, xrays of all fracture clinic referrals from A& E were assessed daily by an Orthopaedic SpR. Time to presentation, site of injury, A& E diagnosis, and A& E time to clinic review, were noted alongside the diagnosis and suggested time to review clinic by the Orthopaedic SpR.

A total of 233 patients were referred. Less than 5% were excluded as non-bony injury and were given an A& E review instead. Overall the majority (85%) of cases had no significant difference in time to clinic review requested by that of the A& E staff and of that requested by the orthopaedic staff. In 4.3% of cases, time to review was increased by more than 4 days whereas 11.3% of cases were seen 5 or more days earlier than that initially requested. There was a variance in diagnosis between A& E and Orthopaedic staff in 24 (10.4%) of cases. The actual time to clinic was within 5 days of that requested by the orthopaedic SpR in 84.7% of patients.

A& E appropriately refer cases to fracture clinic, and in a timely fashion. Review of all A& E referrals by Orthopaedic staff would seem not to be a cost efficient use of time.

NSAIDs inhibit fracture repair, yet the mechanism behind this effect is unknown. It is recognised that NSAIDs impede tumour growth via an inhibition of angiogenesis, primarily via a COX-2 pathway. We propose that the inhibition of fracture repair is via a similar mechanism and have investigated this hypothesis using a murine fracture model. 225 animals were randomised into either treatment (rofecoxib) or control groups and underwent a standard open femoral fracture treated using an external fixator. Outcomes measures involved assessment of healing using radiographic, histolological and biomechanical means; and measurement of blood flow across the fracture gap using Laser Doppler Flowmetry. X-ray analysis showed a similar healing pattern in both groups, however at days 16 and 32 the NSAID group had significantly poorer healing. Histological analysis showed that controls healed quicker (significant at days 24 and 32); and had more bone but less cartilage at day 8. Biomechanical testing showed controls were statistically stronger and stiffer at day 32, while NSAID animals had a significantly greater rate of fixation failure, leading to loss of pin-bone osseointegration; this occurred primarily before day 16. There was no difference in blood flow between the groups on the day of surgery, and both groups exhibited a similar flow pattern; NSAID animals however, exhibited a lower median flow from day 4 onwards, which was significantly poorer at days 4, 16 and 24. Positive correlations were demonstrated between a higher blood flow and both the histological and radiographic results. While NSAIDs were seen to inhibit fracture repair in all outcome measures; and were also noted to decrease blood flow at the fracture, with strong negative correlations being noted between NSAID prescription and fracture repair; multiple regression analysis suggest that this negative effect of NSAIDs on healing is independent of its inhibitory action on blood flow. COX-2 inhibitors are marketed as having cleaner side effect profiles and prescribing is on the rise. Recently however some of the newer COX-2 specific inhibitors have been removed from the market as their seemingly clean side effect profile has come under scrutiny. We have demonstrated that the COX-2 specific inhibitor rofecoxib does has a significant negative effect on fracture repair; and as hypothesised that it also has a significant negative effect on blood flow at the fracture site. While these outcomes strongly correlate, the mechanism behind the effect remains to be elucidated, as we have also demonstrated that these modalities are independent of each other.

The potential importance of bone morphogenic proteins (BMPs) to improve fracture healing is of great interest to orthopaedic surgeons. Although the complex mechanisms leading from the presence of local BMP (either endogenous or exogenous) to form bone is increasingly understood, however most appropriate time to administer exogenous BMP has yet to be elucidated. The purpose of this study was to investigate when BMP may be administered to a fracture arena in order to best improve fracture healing. Forty mice were randomised into 4 groups; (group I) control, treated at day 0 with placebo; (groups II, III and IV) treated with BMP at days 0, 4 and 8, respectively. All animals underwent a previously validated surgical procedure involving the creation of an open femoral fracture which is stabilised using a 4 pin external fixator. Thirty microlitres of bovine serum albumin (BSA) alone was used in group I, and the other groups (II, III and IV) were treated with a combination of the BSA and 2.5 microgrames of rhBMP-2. The BSA and rhBMP were injected through a lateral approach immediately after operation, or at 4, or 8 days postoperatively. At days 0, 8, 16 and 22, sequential radiographs were taken using a digital x-ray machine and at day 22 all animals were sacrificed. Both femora were harvested and assessed biomechanically in 3-point bending prior to fixation for histological evaluation. All data were analysed using Mann-Whitney U tests (SPSS, Version 9, Chicago, Illinois) and differences were considered significant at p < 0.05. X-ray analysis indicated that healing of fractures treated with BMP at day 0(group II) or day 4(group III) was significantly greater than that at both days 16 and 22 (p < 0.05) than those animals in placebo (group I) and BMP day 8(group V) treatment groups. Although the administration of BMP at day 4 seemed to cause more bone formation than treatment at day 0, no significant difference were observed. There were no differences between group IV and group I. Biomechanically, group III exhibited ultimate load values closest to the contralateral unoperated femora followed by group II, then IV and finally the control group I. Significant differences (p < 0.05) were observed between the control animals (group I) and both groups II and III. Qualitative histology suggested that at 22 days after surgery, only groups II and III had healed with woven bone. Group I and group IV had considerable amounts of fibrous tissue and cartilage at the fracture gap. This study suggests that a single percutaneous injection of BMP has a positive effect on fracture healing in this model, when prescribed between the time of injury (day 0) and 4 days. Data suggests that the most effective timing of delivery of BMP may not be at the time of surgery but actually in the early healing phase. The day 4 time point in the mouse model is likely to equate to that of 7–10 days in larger animals or humans. This suggests that current human treatment practices may require further investigation in order to elucidate the most appropriate time of delivery for these important proteins. This work may negate the current requirements for carrier products and large doses of these expensive drugs.

Introduction: Ten percent of fractures end in delayed or non-union. NSAIDs have been linked to an inhibitory action on fracture repair for three decades yet the mechanism of action remains to be elucidated. Cancer research has identified that NSAIDs impede cell proliferation by inhibiting angiogenesis. It is proposed that a similar mechanism occurs in the induction of NSAID induced non-unions. We have investigated this hypothesis in a randomized placebo control trial of the NSAID rofecoxib using a murine femoral fracture model.

Material and Methods: All animals had an open femoral fracture treated using an external fixator. Outcomes measures included x-ray, histology, and biomechanical testing, with laser Doppler used to assess blood flow across the fracture gap.

Results: Radiology showed similar healing patterns in both groups, however at the later stages (day 32) the NSAID group had significantly poorer healing. Histological analysis showed that controls healed quicker (days 24 and 32), with more callus (day 8) and less fibrous tissue (day 32). Biomechanical testing showed that controls were stronger at day 32. Both groups exhibited a similar pattern of blood flow; however NSAIDs exhibited a lower median flow from day 4 onwards (significant at days 4, 16 and 24).

Discussion: Positive correlations were demonstrated between both histological and radiographic assessments of healing, with increasing blood flow. NSAID animals exhibited lower flows, and poorer healing by all outcomes. Regression analysis demonstrates however that the negative effect of NSAIDs on fracture repair is independent of its inhibitory action on blood flow. In conclusion, COX-2 inhibitors are marketed as having cleaner side effect profiles and are widely used in trauma patients. Following development of a novel method of analyzing functional vascularity across a fracture gap, we have demonstrated that the COX-2 inhibitor rofecoxib has a significant negative effect on blood flow at the fracture gap as well as inhibiting fracture repair.

Introduction: Historically, it has been accepted that the pain associated with arthritis of the hip is usually located in the groin, anterior and lateral thigh with occasional radiation to the anterior knee. Patients complaining of thigh pain that extends below the knee are often considered to have a degenerative lumbar spine as the cause for their lower limb symptoms and total hip replacement (THR) may not be offered.

Following review of data regarding the preoperative distribution of pain in 2000 patients attending for hip replacement, it was noted that 40% of these patients had complained of pain at or below the knee.

We proposed to prospectively investigate the severity and location of pain in patients attending for THR and assessed how this distribution of pain altered following surgery. We also proposed to examine the distribution of radiological wear preoperatively and assess if there is any relationship between localisation of pain, and the severity or distribution of the radiological wear pattern.

Methods: 200 consecutive patients undergoing primary THR completed a questionnaire regarding the location and severity of their pain. Pain was localised to one or more of nine areas extending from low back to the foot. The localisation of pain was quantified as to severity using a visual analogue score. Questionnaires were completed both 4 weeks preoperatively and subsequently at a 3-month review clinic.

All patients underwent a standardised preoperative AP and Lateral x-ray. The AP film was divided into three areas, and the lateral film was divided into 5 areas. Each zone was assessed as to the severity of wear pattern and graded from 1–3 (no change in joint space, decreased joint space, femoral or acetabular destruction).

Results: The 200 patients complained of pain in a total of 980 areas preoperatively and 105 areas postoperative. 70% of the patients had complete relief of all pain at 3 months. The most common area of pain identified by patients was to the anterior aspect of the knee (82%), followed by pain at the greater trochanter and groin. 55% patients complained of pain extending to below the knee, mostly over the anterolateral aspect of the leg. Only 7% of these patients continued to complain of any below knee pain postoperatively, and all of these patients still had some relief of their below knee pain at review.

With regard to the frequencies and severity of x-ray changes, zone-1 (34%) was most commonly severely damaged with femoral and/or acetabular destruction in the AP film, with the anterior and anterolateral areas being most commonly affected areas in the lateral film (20% and 19% respectively).

When the distributions and severities of x-ray changes were correlated with the distribution of pain localised pre and postoperatively we were unable to show any association between the degree of radiological wear in any one zone and the locatin of pain identified by the patient. In fact, there was a normal distribution to the severity of radiological damage between each of the zones and localisation of pain in any of the 9 areas.

Conclusions: A significant number of patients who require hip arthroplasty have pain extending below the knee. This pain is frequently relieved following THR. The commonest area of sever hip joint wear with loss of femoral or acetabular bone is antero-superiorly. It is important to recognise this during surgery, such that action can be taken to ensure appropriate reaming such that subsequent correct tissue tension and leg lengths are achieved. We are unable to show any relationship between area of pain and area of radiological degeneration. We believe that patients who complain of pain in their back, buttock or thigh, which extends below the knee, can still benefit from total hip replacement. Patients who attend complaining of low back pain with radiation of pain down their leg should have their hips as well as their lumbar spine examined and imaged. Careful consideration should be taken before labelling the paid as being referred from degenerative back disease.

Introduction: The potential of Bone Morphogenic Protein (BMP) to improve fracture healing is of great interest to orthopaedic surgeons. Although the complex mechanisms leading from the presence of local BMP to the fracture scenario has yet to be elucidated. The purpose of this study was to investigate whether introducing rhBMP-2 to the fracture arena, some days after fixation could be more beneficial to fracture repair.

Methods: 40 animals were randomised into 4 groups; namely control treatment at day 0 or rhBMP-2 treatment at days 0, 4 or 8 post-surgery. All animals underwent a previously validated surgical procedure involving creation of an open femoral fracture fixed using a 4-pin external fixator. 30 μl of bovine serum albumin (BSA) alone (control) or mixed with 2.5 μg of rhBMP-2 (treatments) was injected via a lateral approach directly into the fracture gap, either following closure of the wounds (day 0) or at 4 or 8 days postoperatively. Animals were assessed as to the outcome of surgery by digital sequential x-ray at days 0, 8, 16 and 22 using a Faxitron MX-20 camera; and y either biomechanical testing under a 3-point bending technique (Lloyd Instruments Ltd, UK) or histological examination following sacrifice at day 22. Data were analysed using Mann-Whitney U and Wilcoxon Tests for statistical differences (SPSS, Version 9). Differences were considered significant when p< 0.05.

Results: X-ray analysis indicated that healing of fractures treated with rhBMP-2 at day 0 or day 4 was significantly greater than the two other groups at days 16 and 22. BMP given at day 4 tended to a greater effect than when given at day 0, though the range was too great to show a statistical difference. There were no differences between the BMP-8 and the BSA control groups. Mechanical testing showed that only animals that had received rhBMP-2 at day 4 had attained similar peak loads to failure to those of their contralateral unoperated leg. Bones from animals receiving rhBMP-2 at day 0 had attained the next greatest strength, which was followed by rhBMP-2 administration at day 8 animals, whereas the animals receiving BSA attaining the least strength. There was a statistical difference (p< 0.05) between both rhBMP-2 day 4 and day 0 groups compared to the BSA control group. Qualitative histology suggested that the rhBMP-2 day 0 and day 4 groups had almost fully healed with new bone whereas the BSA and rhBMP-2 day 8 groups still had considerable mounts of fibrous tissue and cartilage at the fracture gap 22 days following surgery.

Conclusions: The study demonstrates that a single percutaneous injection of rhBMP-2 has a positive effect on fracture healing, when prescribed at the time of injury or during the early period of fracture repair. Data suggests that the most effective timing of delivery of BMP may not be at the time of surgery but in the early healing phase. The day 4 time point in the mouse model is likely to equate to that of 7–10 days in larger animals or humans. Further investigation as to the most appropriate time for intervention using these proteins is warranted and may negate the current requirement for carried products and large doses of these expensive drugs.

Introduction: 5–10% of all fractures end in delayed or non-union. It has been reported for 3 decades that NSAIDs have an inhibitory action on fracture repair, yet GPs still prescribe these drugs in up to 50% of fracture patients. Not all fracture patients who are treated with this class of medication go on to develop non-union, yet a strong correlation has been shown in clinical studies between long bone fractures and development of delayed and non-union. The mechanism behind this effect has yet to be elucidated. In cancer research it has been shown that NSAIDs, primarily by a COX-2 pathway, can exert an inhibitory action on cell proliferation by inhibiting angiogenesis. It is proposed that a similar mechanism occurs in the induction of NSAID induced delayed fracture repair. We have investigated this hypothesis using an externally fixated murine model of femoral fracture.

Methods: 158 animals were randomised into either treatment (Rofecoxib 5mg/kg/day in a 0.5% methylcellulose carrier) or control (carrier alone). All had a standard surgical regimen involving creating of an open femoral fracture with treatment using a 4-pin external fixator under the isoflurane inhalational anaesthesia. Outcome measures included standardised x-rays (Faxitron MX-20) and Laser Doppler Flow (Oxford Optronics) measurements taken at days 0, 4, 8, 16, 24 and 32, along with biomechanical testing (Lloyd Instruments Ltd) at days 24 and 32. Data was entered into a spreadsheet and analysed using Mann-Whitney U and Wilcoxon Tests for statistical differences (SPSS, Version 9), with statistical significance being attained when p< 0.05.

Results: A greater number of animals in the NSAID group had a failure of treatment with loss fixation due to pin pullout from poor osseointegration (53% NSAID compared to 26% controls). Of those animals that completed the studies, x-ray analysis showed a change in pixel density at the fracture gap suggesting poorer healing of the NSAID animals that was statistically different at days 16, 24 and 32. Biomechanical testing suggested treatment animals had attained statistically less peak loads and stiffness at day 32. Laser Doppler Flow measurements across the fracture gap showed generally less flow at all time points in the NSAID group. This was statistically significant at days 4 and 24.

Conclusions: The new selective and specific COX-2 inhibitors are marketed as having a cleaner side effect profile and are being widely used by primary care practitioners in trauma patients. Not all animals that are treated with NSAIDs go on to develop a delayed union and some are able to heal with similar mechanical properties to animals in a control group. However, we have illustrated that the highly specific COX-2 inhibitor rofexcoxib has a significant negative effect on maintenance of fracture fixation and fracture repair in this model, both in terms of x-ray and biomechanical analysis. We have also shown that the inhibition of fracture healing is associated with a decrease in blood flow at the fracture site leading to the hypothesis that the mechanism behind the effect is via an inhibition of angiogenesis.

Introduction: Historically, it has been accepted that pain associated with arthritis of the hip is usually located in the groin and thigh with radiation to the anterior knee. However pain below the knee, and into the foot was not believed to be associated with arthritis of the hip. Patients complaining of thigh pain that extends below the knee are often considered to have a degenerative lumbar spine as the cause for their lower limb symptoms, and hip arthroplasty may not be offered. We examined the severity and location of pain in patients attending for arthroplasty and assessed how this altered following surgery.

Methods: 200 consecutive patients undergoing primary total hip arthroplasty completed a questionnaire regarding the location and severity of pain in the leg and also an Oxford hip score to assess functionality. These were completed approximately 4 weeks preoperatively and again at a 3-month review clinic.

Results: 57% (114/200) of patients complained of pain below their knee preoperatively. Only 9% (10/114) of these patients continued to complain of pain postoperatively, and of these patients their mean pain score decreased by 44% (9 to 5). Only 1% (2/200) of all patients complained solely of pain in the knee or more distally, and both of these had complete relief of pain 3 months postoperatively.

Conclusion: A significant number of patients with degenerative hip disease have pain below the knee. Patients who complain of pain in their back, buttock or thigh, which extends below the knee, may still benefit from total hip replacement. Careful consideration should be taken before labelling the pain as being referred from degenerative back disease.