Metal and ceramic humeral head bearing surfaces are available choices in anatomical shoulder arthroplasties. Wear studies have shown superior performance of ceramic heads, however comparison of clinical outcomes according to bearing surface in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) is limited. This study aimed to compare the rates of revision and reoperation following metal and ceramic humeral head TSA and HA using data from the National Joint Registry (NJR), which collects data from England, Wales, Northern Ireland, Isle of Man and the States of Guernsey. NJR shoulder arthroplasty records were linked to Hospital Episode Statistics and the National Mortality Register. TSA and HA performed for osteoarthritis (OA) in patients with an intact rotator cuff were included. Metal and ceramic humeral head prostheses were matched within separate TSA and HA groups using propensity scores based on 12 and 11 characteristics, respectively. The primary outcome was time to first revision and the secondary outcome was non-revision reoperation.Aims
Methods
The purpose of this study was to evaluate the cost of reverse shoulder arthroplasty (RSA) for patients with a proximal humerus fracture, using time-driven activity based costing (TDABC), and to compare treatment costs with reimbursement under the Healthcare Resource Groups (HRGs). TDABC analysis based on the principles outlined by Kaplan and a clinical pathway that has previously been validated for this institution was used. Staffing cost, consumables, implants, and overheads were updated to reflect 2019/2020 costs. This was compared with the HRG reimbursements.Aims
Methods
Patients with recurrent anterior dislocation of the shoulder commonly have an anterior osseous defect of the glenoid. Once the defect reaches a critical size, stability may be restored by bone grafting. The critical size of this defect under non-physiological loading conditions has previously been identified as 20% of the length of the glenoid. As the stability of the shoulder is load-dependent, with higher joint forces leading to a loss of stability, the aim of this study was to determine the critical size of an osseous defect that leads to further anterior instability of the shoulder under physiological loading despite a Bankart repair. Two finite element (FE) models were used to determine the risk of dislocation of the shoulder during 30 activities of daily living (ADLs) for the intact glenoid and after creating anterior osseous defects of increasing magnitudes. A Bankart repair was simulated for each size of defect, and the shoulder was tested under loading conditions that replicate Aims
Patients and Methods
We present a case series of patients who underwent 3 or 4 part proximal humerus fracture fixation using an intra-osseous suture technique. 18 patients are included in the study with follow up data obtained ranging from 1 to 4 years. Oxford Shoulder Scores (OSS) and range of movement measurements were taken for all patients. The mean OSS for the group was 50/60 with a mean forward flexion of 140°, abduction of 132°, external rotation of 48° and internal rotation to the level 10th thoracic vertebra. Three patients developed adhesive capsulitis, 2 requiring subsequent arthroscopic release. This data compares favourably to outcomes reported in the literature with hemiarthroplasty or locking plate fixation. An activity based costing analysis estimated that the treatment costs for proximal humerus fractures was approximately £2,055 when performing a soft tissue reconstruction, £3,114 when using a locking plate and £4,679 when performing a hemiarthroplasty. This demonstrates a significant financial saving when using intra-osseous fixation compared to other fixation techniques. We advocate the use of the intra-osseous suture fixation technique for certain 3 and 4 part fractures. It gives good functional outcomes, significant cost savings and potentially makes revision procedures easier when compared to other fixation techniques.
The objective of this study was to perform a meta-analysis of all randomised controlled trials (RCTs) comparing surgical and non-surgical management of fractures of the proximal humerus, and to determine whether further analyses based on complexity of fracture, or the type of surgical intervention, produced disparate findings on patient outcomes. A systematic review of the literature was performed identifying all RCTs that compared surgical and non-surgical management of fractures of the proximal humerus. Meta-analysis of clinical outcomes was performed where possible. Subgroup analysis based on the type of fracture, and a sensitivity analysis based on the type of surgical intervention, were also performed.Objectives
Methods
Optimal orthopaedic implant placement is a major contributing factor to the long term success of all common joint arthroplasty procedures. Devices such as 3D printed bespoke guides and orthopaedic robots are extensively described in the literature and have been shown to enhance prosthesis placement accuracy. These technologies have significant drawbacks such as logistical and temporal inefficiency, high cost, cumbersome nature and difficult theatre integration. A radically new disruptive technology for the rapid intraoperative production of patient specific instrumentation that obviates all disadvantages of current technologies is presented. An ex-vivo validation and accuracy study was carried out using the example of placing the glenoid component in a shoulder arthroplasty procedure. The technology comprises a re-usable table side machine, bespoke software and a disposable element comprising a region of standard geometry and a body of mouldable material. Anatomical data from 10 human scapulae CT scans was collected and in each case the optimal glenoid guidewire position was digitally planned and recorded. The glenoids were isolated and concurrently 3D printed. In our control group, guide wires were manually inserted into 1 of each pair of unique glenoid models according to a surgeon's interpretation of the optimal position from the anatomy. The same surgeon used the guidance system and associated method to insert a guide wire into the second glenoid model of the pair. Achieved accuracy compared to the pre-operative bespoke plan was measured in all glenoids in both the conventional group and the guided group.Introduction
Methods
The aims of this study were to estimate the cost of surgical
treatment of fractures of the proximal humerus using a micro-costing
methodology, contrast this cost with the national reimbursement
tariff and establish the major determinants of cost. A detailed inpatient treatment pathway was constructed using
semi-structured interviews with 32 members of hospital staff. Its
content validity was established through a Delphi panel evaluation.
Costs were calculated using time-driven activity-based costing (TDABC)
and sensitivity analysis was performed to evaluate the determinants
of costAims
Methods
The reliability of currently available proximal humeral fracture classi?cation systems has been shown to be poor, giving rise to the question whether a more objective measure entails improved predictability of surgical outcome. This study aims to apply a novel software system to predict the functional range of motion of the glenohumeral joint after proximal humeral fracture. Using a validated system that simulates bone-determined range of motion of spheroidal joints such as the shoulder joint, we categorically analysed a consecutive series of 79 proximal humeral fractures. Morphological properties of the proximal humerus fractures were related to simulated bone-determined range of motion.Introduction
Method
Tears of the rotator cuff are a common pathology and poorly understood. Achieving a good functional outcome for patients may be difficult, and the degree of fat infiltration into the muscle is known to be a major determining factor to surgical repair and post operative function. It is the hypothesis of this study that the degree of retraction of the common central tendon as seen on MRI corresponds to the amount of fat infiltration classified according to the Goutallier grading System. MRI scans of the supraspinatus were reviewed and two groups identified: no tear (NT) and full thickness tear (FTT). The following measures were taken: central tendon retraction (CTR) and the Goutallier Grade according to MRI. The difference between Goutallier grade between NT and FTT were measured using the Mann-Whitney test. The relationship between Goutallier grade and increasing amount of CTR was described using Spearman's rank correlation and differences assessed using Mann-Whitney tests.Background
Methods
There is no non-invasive gold standard for measuring gap formation following rotator cuff repair; re-tears are reported both on MRI and Ultrasound. Roentgen Stereophotogrammetric Analysis (RSA) has previously been used to monitor microscopic migration of markers in rigid bodies. We present a novel RSA technique using a combination of 1mm tantalum beads and metal sutures to allow accurate monitoring of gap formation following rotator cuff repair. The RSA system combines a commercially made calibration cage with software developed at Imperial College. We verified the RSA system by analysing a movable glass phantom and comparing the data with precise physical measurements of the same object: it identified a 2mm distraction of the phantom to within 0.05mm. In vitro work involved cadaveric human shoulders. We placed three 1mm RSA tantalum beads in the greater tuberosity and three metal sutures in supraspinatus tendon. We then created a tear in supraspinatus at its insertion into the greater tuberosity. We were able to show that RSA images taken before and after the tear correlated closely with direct measurements. The processed data demonstrated movement associated with gap formation. We have performed two open rotator cuff repairs using trans-osseous sutures. During surgery RSA markers were inserted into the shoulder to allow post-operative monitoring of the repair (guided by the in vitro work). Direct measurements of the distance between markers each side of the repair were taken intra-operatively (T=O). RSA images were taken immediately post-operatively (T=1 hours), day 3, day 14, and day 84. The RSA data suggests gapping of typically 3mm may have occurred at the repair sites in both patients. Ultrasound imaging was performed at the same intervals by consultant musculoskeletal radiologists blinded to the RSA data. Preliminary results correlating the two modalities suggest that ultrasound can visualise gap formation accurately even immediately post-operatively.
The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device. The video scores were significantly different for the three groups in all three procedures (p <
0.05), with excellent inter-rater reliability (α = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p <
0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p >
0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment. This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.
This study aimed to quantify the relationship between passive tension of rotator cuff repair and arm position intraoperatively and to examine the effect of the passive tension on gap formation in cadaveric rotator cuff repairs. Five patients undergoing open surgical reconstruction of the rotator cuff were recruited. The operations were performed by a single surgeon using a standardised technique, which was acromioplasty, minimal debridement, mobilisation of tissue, bone troughs and transosseous suture tunnels. A Differential Variable Reluctance Transducer (DVRT) was placed at the apex of the debrided tendon. An in situ calibration was performed to relate the output from the DVRT to actual tension in the tendon. The tension generated was recorded as the supraspinatus tendon was advanced into a bone trough and secured. The relationship between arm position and repair tension was measured, by simultaneously collecting data from the DVRT and a calibrated goniometer. Particular attention was paid to the three standard positions of post-operative immobilisation; full adduction with internal rotation, neutral rotation with a 30° abduction wedge and ninety degrees of abduction. Five cadaveric shoulders were used for the creation of standardised rotator cuff tears which were then repaired using the technique described above. The difference in tension measured between full adduction and 30° abduction was statically applied for twenty four hours and the gap formation measured. Repair tension increased with advancement of the supraspinatus tendon into the bone trough. Abduction reduced the repair load, this was observed mainly in the first 30° of abduction. The mean reduction in load by 30° of abduction was 34 N. Twenty four hours of 34N static loading caused gap formation in each cadaveric rotator cuff repairs, the mean was 9.2 mm. Rotator cuff repairs tension can be reduced by postoperative immobilisation in 30° abduction. The change in tension with full adduction was caused gap formation in cadaveric rotator cuff repairs.
Differential strain has been proposed to be a causative factor in failure of the supraspinatus tendon. We quantified the strains on the joint and bursal sides of the supraspinatus tendon with increasing load (20 to 200 N) and during 120° of glenohumeral abduction with a constant tensile load (20 to 100 N). We tested ten fresh frozen cadaver shoulders on a purpose-built rig. Differential variable reluctance extensometers allowed calculation of the strain. Static loading to 100 N or more increased strains on the joint side significantly more than on the bursal side. During glenohumeral abduction an increasing and significant difference in strain was measured between the joint and bursal sides of the supraspinatus tendon, which reached a maximum of 10.6% at abduction of 120°. The joint side strain of 7.5% reached values which were previously reported to cause failure. Differential strain causes shearing between the layers of the supraspinatus tendon, which may contribute to the propagation of intratendinous defects that are initiated by high joint side strains.
In vivo loading data for the rotator cuff would be of value to scientists and clinicians interested in the shoulder in the testing of surgical repairs, design of rehabilitation programs and for finite element models. A technique for insertion and retrieval of the Arthroscopically Insertable Force Probe (AIFP - Microstrain Inc. Burlington, Vermont, USA) from the subscapularis is described was initially established in a cadaveric model. Ethical approval was obtained for AIFP insertion into the subscapularis tendon of volunteers during diagnostic shoulder arthroscopy. An in situ calibration was carried out using a modified arthroscopic grasper ( Smith and Nephew, Huntingdon, UK). After motor effects of interscalene block had worn off dynamic data relating to subscapularis tendon loading was collected. The AIFPs were removed through a port site by traction on an O (3.5 metric) nylon suture without complication. Maximum loading of the subscapularis tendon was measured during internal rotation from neutral with the arm fully adducted. Forces measured exceeded 200N. This paper describes a novel technique for the insertion, calibration and retrieval of AIFPs from the rotator cuff. In vivo tendon loading data was obtained. The techniques described may be applied to other structures of interest to orthopaedic surgeons.
To quantify the variation in strain between the deep and superficial layers of the supraspinatus tendon, ten cadaveric shoulders were tested on a purpose built rig. Differential Variable Reluctance Transducers (DVRTs) were inserted into the superficial and deep aspects of the tendon spanning the critical zone. DVRTs accurately measured linear displacement and from this strain was calculated. The strain was measured for two aspects of supraspinatus action, abduction from 0 to 120 degrees with a tensile load (100 Newtons) and static load increases at zero abduction (20, 50, 100, 150 and 200 Newtons). After preconditioning, ten sets of results were recorded for each load/position. The hypothesis, there is a statistically significant difference in strain between the superficial/deep supraspinatus tendon during abduction and with static loading, was tested using a one way ANOVA. During abduction a statistically significant difference in strain was measured between the layers of the supraspinatus tendon at thirty degrees (p=0.000428) and this increased with further abduction. Tensile loading increased tendon strain more in the deep layer of the tendon. This was statistically significant at loads greater than 150N (p= 0.007). The variation in properties between the superficial and deep layers of the supraspinatus tendon has been proposed as a cause of differential strain (1). This study confirms statistically different strains between the superficial and deep tendon layers. It is proposed that the resulting shearing effect initiates intratendinous defects and ultimately tears.
