Introduction

We describe our experience with a minimally invasive Chevron and Akin (MICA) technique for hallux valgus correction. This technique adheres to the same principles as open surgical correction but is performed using a specialized high-speed cutting burr under image intensifier guidance via tiny skin portals.

Introduction

Scaphoid fracture is the most common undiagnosed fracture. Occult scaphoid fractures occur in 20-25 percent of cases where the initial X-rays are negative. Currently, there is no consensus as to the most appropriate investigation to diagnose these occult frctures. At our institution MRI has been used for this purpose for over 3 years. We report on our experience and discuss the results.

14.1% of men & 22.8% of women over 45 years show symptoms of osteoarthritis OA of the knee [1]. Knee OA is usually associated with lower limb malalignment [2]; 50 of varus results in 70% −90% increase in compressive loading of the medial tibio-femoral compartment [3] and OA worsening over 18 months [4]. High Tibial Osteotomy (HTO) enables preservation of bone stock and soft tissue structures and could be an attractive option to younger patients who wish to return to high level activity. However, results of HTOs are unpredictable, which could be due to patient selection or surgical techniques. The long-term aim of this work is to develop a predictive tool to aid the surgeon in the selection of optimal HTO geometry for improved and more consistent surgical outcomes. The first step in achieving our longterm goal was to determine whether stress predictions at the tibio-femoral articulation were sensitive to simulated high tibial osteotomy, using finite element (FE) method.

CT and MRI data of a cadaveric knee were used to create geometrically accurate 3D models of the femur, tibia, fibula, menisci and cartilage and tendon of the knee joint, using the Mimics V12.11 commercially-available software (Materialise, Belgium). The Simulation module was used to register the bones and the soft tissues. The resulting STL files were exported to CATIA V5R18 pre-processor to generate surface meshes and create the corresponding 3D solid and FE models of the osseous and soft tissues from the STL cloud of points.

The Young’s moduli for cortical bone, cancellous bone, cartilages, menisci and ligaments were taken from literature as 17 GPa, 500 MPa, 12 MPa, 60 Mpa and 1.72 MPa respectively [5,6,7]. The Poisson’s ratios for osseous and soft tissues were taken as 0.3 and 0.45, respectively [8]. The nodes between the bones and the corresponding cartilages were merged and surface contact was applied between the cartilages. The distal ends of the tibia and fibula were fixed and a load of 2.1 KN, corresponding to 3 x body weight, was applied perpendicularly to the proximal end of the femur. Results of finite element analyses show a reduction of 67 % in principal stresses in the knee joint following an open wedge HTO surgery simulating 100 varus correction.

FE analysis results of this study show that HTO reduces stresses in specific regions of the knee, which are associated with OA progression [4]. Our future works include corroborating our results with controlled cadaveric experiments and implementing optimization techniques to predict optimum HTO geometries for patient-specific FE models.

Introduction: Acetabular fractures are increasing in incidence and no previous published studies have reviewed the factors influencing the outcome of operative stabilization on the neural function and recovery. The incidence, outcome and recovery of operatively managed acetabular fractures with associated neural injuries were studied from a three-year cohort of patients.

Methods: This retrospective case series study of 456 referrals to a tertiary referral unit, from 1st Jan 2004 to 31st Dec 2006, identified 29 (6.3%) acetabular fractures associated with neural injuries. The fractures were classified using the Letournel system, neural injuries classified as either complete or incomplete and the degree of post-operative skeletal displacement quantified using radiographs. A mean clinical and radiographic follow up of 3.5 years was achieved and statistical analysis was performed used chi-squared (SPSS)

Results: Overall, the cohort had a mean age of 34 years, 17 (59%) were male and the mean delay from time of injury to time of acetabular surgery was 16 days (range 4 – 53 days). All fractures involved posterior wall and/or posterior column and 23 (79%) were of the more complex, associated type, Letournel fracture patterns. Full resolution of neural symptoms was observed in 9 (31%) patients with a mean fracture reduction of 1.6mm. Partial neurological improvement was observed in 15 patients. Ongoing complete nerve palsy was observed in 5 patients, associated with a mean fracture reduction of 2.5 mm and a significantly longer delay to surgery of 32 days (p< 0.05).

Discussion: Acetabular fractures involving the posterior wall or column have a high incidence of neural injury. Accurate fracture reduction and stabilization, achieved without a prolonged delay, affords a good neural outcome for these patients. In similiar injuries with complete nerve palsy, delayed and sub-optimal surgical reduction predicts a poor prognosis.

Introduction: The incidence, outcome and recovery of operatively managed pelvic ring fractures were studied from a three-year cohort of patients. No previous published studies have reviewed the factors influencing the outcome of operative stabilization on the neural function and natural recovery in these potentially devastating injuries.

Methods: This retrospective case series study of 489 referrals to a tertiary referral unit, from 1st Jan 2004 to 31st Dec 2006, identified 42 (8.6%) patients who had sustained pelvic ring injuries with associated neural injuries. Each pelvic injury was classified using the Tile and Burgess & Young classifications, neural injuries were classified as either complete or incomplete and the degree of post-operative skeletal displacement was quantified using radiographs. A mean clinical and radiographic follow up of 3.5 years was achieved and statistical analysis was performed used chi-squared (SPSS)

Results: The mean age of patients with neural injuries was 28 years, 32 (76%) were male and 37 (88%) had unstable, Tile type C, fracture patterns. The mean delay from time of injury to time of pelvic surgery was 11 days (range 3 – 42 days). Full resolution of neural symptoms was observed in 16 (38%) patients, with a mean fracture reduction of < 6mm. Incomplete improvement was observed in 11 patients and 15 patients had ongoing complete lumbosacral palsy. Patients who failed to achieve full resolution of neural function had a mean fracture or sacro-iliac joint reduction of 8.8 mm and the mean delay to surgery was 24 days.

Discussion: Pelvic ring injuries with an unstable fracture pattern are associated with a high incidence of neural injury. Accurate fracture reduction and stabilization, achieved without a prolonged delay, creates a better environment to achieve a good neural outcome. In such injuries with complete nerve palsy, delayed and suboptimal surgical reduction predicts a poor prognosis.

Introduction: Acetabular fractures are increasing in incidence and no previous published studies have reviewed the factors influencing the outcome of operative stabilization on the neural function and recovery. The incidence, outcome and recovery of operatively managed acetabular fractures with associated neural injuries were studied from a three-year cohort of patients.

Methods: This retrospective case series study of 456 referrals to a tertiary referral unit, from 1st Jan 2004 to 31st Dec 2006, identified 29 (6.3%) acetabular fractures associated with neural injuries.

The fractures were classified using the Letournel system, neural injuries classified as either complete or incomplete and the degree of post-operative skeletal displacement quantified using radiographs.

A mean clinical and radiographic follow up of 3.5 years was achieved and statistical analysis was performed used chi-squared (SPSS)

Results: Overall, the cohort had a mean age of 34 years, 17 (59%) were male and the mean delay from time of injury to time of acetabular surgery was 16 days (range 4 – 53 days).

All fractures involved posterior wall and/or posterior column and 23 (79%) were of the more complex, associated type, Letournel fracture patterns.

Full resolution of neural symptoms was observed in 9 (31%) patients with a mean fracture reduction of 1.6mm. Partial neurological improvement was observed in 15 patients.

Ongoing complete nerve palsy was observed in 5 patients, associated with a mean fracture reduction of 2.5 mm and a significantly longer delay to surgery of 32 days (p< 0.05).

Discussion: Acetabular fractures involving the posterior wall or column have a high incidence of neural injury. Accurate fracture reduction and stabilization, achieved without a prolonged delay, affords a good neural outcome for these patients. In similiar injuries with complete nerve palsy, delayed and sub-optimal surgical reduction predicts a poor prognosis.

Purpose: The purpose of this study was to compare the biomechanical behavior of locking plates to conventional plate and allograft constructs for the treatment of periprosthetic femoral fractures.

Methods: Twenty synthetic femora were tested in axial compression, lateral bending and torsion to characterize initial stiffness and stiffness following fixation of an osteotomy created at the tip of a cemented femoral component. Stiffness was tested with and without a 5mm gap. Axial load to failure was also tested. Four constructs were tested: Construct A – Synthes locked plate with unicortical locked screws proximally and bicortical locked screws distally; Construct B – Synthes locked plate with alternate unicortical locked screws and cables proximally and bicortical locked screws distally. Construct C – Zimmer cable plate with alternate unicortical non locked screws and cables proximally and bicortical non locked screws distally. Construct D – Zimmer cable plate in same fashion as construct C plus anterior strut allograft secured with cables proximally and distally.

Results: In axial compression, construct D was significantly stiffer compared with all other constructs in the presence of a gap, with no differences between groups without a gap. For lateral bending stiffness, construct D was significantly stiffer than the other groups with and without a gap. In torsional testing, construct D was significantly stiffer than all other constructs in the presence of a gap. With no gap, construct D was significantly stronger than construct B. There were no significant differences between constructs A and B in all testing modalities. Axial load-to-failure ranged from 5561.5 to 6700.2 N. There were no significant differences in axial load to failure.

Conclusions: This study suggests that a single locked plate does not provide the same initial fixation stiffness as a plate-allograft strut construct in the setting of a gapped osteotomy. This may be particularly important in the setting of a comminuted fracture or with bone loss. In these settings, a construct with a lateral plate and an allograft strut placed anteriorly at 90 degrees to the plate, may be optimal.

Purpose: The purpose of this study was to examine how the “ideal” tibial nail insertion point varies with tibial rotation and to determine what radiographic landmarks can be used to identify the most suitable rotational view for insertion of a tibial intramedullary nail.

Methods: Twelve cadaveric lower limb specimens with intact soft tissues around the knee and ankle joints were used. A 2.0mm Kirschner wire was placed in the center of the anatomic safe zone and centered on the tibial shaft. The leg was rotated and imaged using a fluoroscopic C-arm until the K-wire was positioned just medial to the lateral tibial spine (defined as the neutral anteroposterior radiograph). The leg was then fixed and radiographs were taken in 5 degree increments by rotating the fluoroscope internally and externally (in total, a 50 degree arc). Following this a second K-wire was placed in 5 mm increments both medially and laterally and the fluoroscope rotated until this second K-wire was positioned just medial to the lateral tibial spine. Radiographs were digitized for measurements.

Results: Given the presence of a 30 degree rotational arc through which the radiograph appeared anteroposterior, it was possible to improperly translate the start point up to 15 mm. Relative external rotation of the image used for nail placement led to a medial insertion site when using the lateral tibial spine as the landmark. A line drawn at the lateral edge of the tibial plateau to bisect the fibula head correlated with an entry point that was central or up to 5 mm lateral to the ideal entry point. The use of a fibula head bisector line avoided a medial insertion point.

Conclusions: Rotation of the tibia may result in up to 15 mm of translation of the start point that may be unrecognized. Relative external rotation of the film used for nail placement leads to medial insertion sites when using the lateral tibial spine as a landmark. The fibula head bisector line can be used to avoid choosing external rotation views and thus avoid medial insertion points.

Purpose: This cadaveric study examines how changes in femoral entry point for intramedullary instrumentation of total knee replacements affects femoral component positioning.

Methods: Twelve cadaveric lower limb specimens with intact hip, knee and ankle joints were obtained. Total knee navigation instrumentation was secured. Anatomical landmarks required for axes generation were obtained. An initial entry point was made at the center of the distal femur. An intramedullary rod was the introduced into the femur. Five and seven degree cutting blocks were placed onto the rod and positioned against the distal femur with the rotation parallel to the epicondylar axis. The navigation system was then used to generate a varus/valgus angle and flexion/extension angle with respect to the previously generated femoral mechanical axes. This allowed determination of an angle at which the distal femoral cutting block would need to be set to make a neutral distal femoral cut. The guide rod was removed and reinserted five times and measurements recalculated. Data was then collected with entry points 5mm medial, 5mm anterior and 5mm medial and anterior to the initial entry point.

Results: There was no significant difference in varus/ valgus angle with a central compared with 5mm anterior entry point and no difference with a 5mm medial versus 5 mm medial and anterior entry point. The valgus angle required to give a neutral distal femoral cut with a central entry point was 4.98o (SD 0.91o; range 3.5o–6.0o). The valgus angle for a 5mm medial entry point was 6.92o (SD 0.97o, range 5.5o–8.0o). With regards to the sagittal plane a 5mm anterior translation of the entry point changed the flexion/extension angle by 1.58o (SD 0.52o, range 0.5o–2.5o).

Conclusions: Small changes in the entry point can significantly affect component alignment. When moving more medial with the entry point a more valgus angle is required for the cutting block. An entry point at the deepest point of the trochlea may be more reproducible than an anteromedial one but requires a valgus cutting block closer to 5 degrees.

Funding : Commerical funding

Funding Parties : Stryker

The purpose of this study was to determine which activities are important to patients and to determine the severity of those problems. The five most important activities were walking outside, driving, walking indoors, stair climbing and daytime pain. Importance of these did not change postoperatively. The five most severe problems causing limitation were a limp, stiffness, loss of energy, daytime pain and locking. All these activities become statistically less severe over twenty-four months. Activities that are important to patients are different than the problems that are ranked by severity. Surgeons can educate patients that the severity of problems do improve over time following TKA.

The objectives of this study were:

to determine the five most important activities and five most severe problems for patients prior to total knee arthroplasty (TKA) using the Patient Specific Index (PASI) and

Activities that are most important to patients are different than problems that patients find severe. Important activities remain important over time. Severe problems become less severe over time.

Functional activities and PASI scores improve after TKA. Surgeons can educate patients that the problems they find most severe preoperatively do improve over time following TKA. Important activities remain important.

Patients scheduled for elective primary (or revision) TKA at two tertiary care teaching hospitals were enrolled in the study, excluding those not fluent in English and those undergoing TKA for a tumour, acute fracture, or an infection of the prosthesis. Patients completed the PASI pre-operatively, six, twelve and twenty-four months post-operatively.

One hundred and nineteen subjects were enrolled, nineteen were excluded. The five most important activities (ten- point scale, ten is most important) preoperatively were (mean; 95% CI): walking outside (6.25; 6.23–6.27), driving (6.17; 6.12–6.22), walking indoors (6.14; 6.12–6.16), climbing stairs (6.12; 6.10–6.14), and daytime pain (5.84; 5.81–5.87). These activities were not statistically less important over time. The most severe problems were limping (4.81; 4.77–4.85), stiffness (4.59; 4.56–4.62), lack of energy (4.51; 4.47–4.55), daytime pain (4.46; 4.43–3.39) and locking (4.38; 4.27–4.49). These were significantly less severe at twenty-four months (p < .001).

Introduction and Aims: Pectoralis major tendon rupture is a relatively rare injury, resulting from violent, eccentric contraction of the muscle. Over 50percent of these injuries occur in athletes, classically in weight-lifters during bench press.

Method: In this study, 13 cases of rupture of the pectoralis major muscle in athletes are presented. All patients underwent surgical repair. Physical findings and surgical technique are described. Magnetic resonance imaging was used in the diagnosis of all patients. Intra-operative findings correlated with the reported scans in 11 patients with minor differences in two patients.

Results: During follow-up examination, six patients had excellent results, six had good results and one had a fair result. Eleven patients could return to sports activity at their pre-operative level.

Among our patients we emphasise that of an orthopaedic resident who suffered a rupture of his pectoralis major tendon as an unusual complication of closed manipulation of an anterior shoulder dislocation.

Conclusion: According to the literature and our experience, we suggest that only surgical repair of the pectoralis major rupture will result in complete recovery and restoration of the full strength of the muscle, which is essential for the active athlete.

External fixation of distal radius fractures usually involves the use of a bridging fixator. However, immobilisation of the wrist can be associated with various complications and therefore dynamic external fixators were developed to allow wrist mobilisation with the fixator in place. But dynamic fixators themselves are not without complications and more recently interest has been rekindled in non-bridging external fixators (otherwise called metaphyseal or radial-radial fixators).

Following a pilot study using a non-bridging external fixator (Delta frame) in the treatment of intra-articular distal radius fractures, our aim in this study was to compare the functional and radiological outcome of the Delta frame and a standard wrist-bridging static external fixator in the treatment of such fractures. Sixty patients with intra-articular distal radius fractures were randomly allocated to receive either a static bridging Hoffman external fixator or a non-bridging Delta frame. All patients had the fixator removed at six weeks. Clinical and radiographic assessment was performed regularly up to a maximum of twelve months with the clinical results being expressed in terms of range of movement, pain, grip strength and ability to perform certain activities of daily living. Radiological assessment was performed by an independent radiologist. Mean follow-up was ten months.

The only sustained significant difference in function was a greater range of flexion in the Hoffman group. No significant difference could be detected between the two groups in terms of the radiological outcome. Complications included pin-site infection, paraesthesia, extensor pollicis longus tendon rupture and chronic regional pain syndrome. Three patients underwent further surgery. We did not demonstrate any advantage in the use of a non-bridging fixator in the treatment of intra-articular distal radius fractures.

Introduction: Current fixation methods for distal radial fractures usually involve immobilisation, which has been suggested to have adverse effects on wrist function. The aims of this study were to compare the clinical, functional and radiological outcomes of a bridging, and a non-bridging external fixator that did not cross the wrist joint, in the management of intra-articular fractures of the distal radius.

Methods: Sixty subjects were randomly allocated to receive a bridging Hoffman frame and limited wrist range of movement (ROM) exercises for 6 weeks, or a non-bridging Delta frame and full active wrist ROM exercises commencing at 2 weeks. All frames were removed at 6 weeks. Radiographic and clinical assessments were made at regular postoperative time intervals for 12 months with clinical outcomes including measures of pain, ROM, grip strength, function and quality of life.

Results: Preliminary clinical results analysing pain, grip strength and ROM including flexion, extension, pronation and supination at 1–6, 26 and 52 weeks postoperatively indicated that no statistically significant difference could be detected between the two groups at any time frame. Complication rates were similar for both groups. Preliminary radiographic analysis of dorsal angle, radial angle and radial length at 6, 26 and 52 weeks postoperatively also indicated that no statistically significant difference could be detected between the two groups.

Conclusion: Preliminary results of this trial suggest that no difference can be detected in the clinical and radiographic outcomes of subjects receiving a bridging external fixator with limited early wrist ROM exercises, or a non-bridging external fixator with early full active ROM exercises in the management of intra-articular fractures of the distal radius.