In the UK we have many surgeon inventors – surgeons who innovate and create new ways of doing things, who invent operations, who design new instruments to facilitate surgery or design new implants for using in patients. However truly successful surgeon inventors are a rare breed and they need to develop additional knowledge and skills during their career in order to push forward their devices and innovations. This article reviews my own experiences as a surgeon inventor and the highs and lows over the whole of my surgical career.

Objective: To analyse the author’s personal use of shoulder replacements over the past 5 years, to report on his personal experience and to review the published literature on the results from both conventional and inverse Total Shoulder Replacement. Methodology: The author has kept a logbook of all his operations since 1986. Nottingham is a tertiary referral centre for shoulder surgery. The numbers of Shoulder Replacement operations carried out from 2004 to 2008 has been analysed, looking specifically at the proportion of Inverse Shoulder replacements being inserted. The published literature has been reviewed to identify the success and failure rates from conventional and inverse shoulder replacements. Results: The table summarises the number of shoulder arthroplasties inserted over the past 5 years. The proportion of inverse primary arthroplasties has risen from 16% to 33%.

However the complication rates have been noticeably higher for the Inverse shoulder arthroplasties with 2/44 (5%) not being completed at surgery and 5/44 (11%) requiring surgical revision subsequently. This experience mirrors that of other publications which will be summarised.

Conclusion: Inverse shoulder replacement is a good operation for patients over 70 with large and massive rotator cuff tears. For younger patients and other indications the complication rate may be unacceptably high and the “bail out” options at revision surgery are limited and challenging. The take home message is use this prosthesis with caution and you must counsel your patient before surgery about the serious complications which may occur.

Data were collected on patients undergoing subacromial decompression (SAD) in our routine practice from 1998 to 2004. All patients had clinical signs of subacromial pain and had failed conservative treatment. Tears were not repaired. Data on age, gender, arm dominance and presence of cuff tear at operation were recorded. At six months post-operatively, patients were assessed with the Constant Score (CS). Data were analysed using multiple linear regression. Data on 427 patients were collected, 168 having rotator cuff tears. The mean age was 55.41 years (SD 12.00). There were 233 women and 191 men. There were no significant gender differences between the two groups (x2=2.34, df=1, p=0.13). The group with cuff tears were significantly older by 10.24 years (p< 0.001, 8.10 to 12.38). Power of the study was 90% at the 5% significance level. Multiple linear regression showed that gender, age and presence of a cuff tear all had a significant effect on the CS. Gender B = 5.52 (1.99 to 9.06) p = 0.002 Age B = −0.31 (−0.48 to −0.15) p < 0.001 Cuff tear B = −5.51 (−9.48 to −1.55) p = 0.007 Hand dominance and the side operated upon had no significant effect. We found that in patients with symptomatic shoulders, who had failed conservative treatment and undergone an SAD, the CS at six months follow up was lower in those who had a cuff tear. There was increased tear prevalence in slightly older patients, and these scored on average 5.5 (1.5 to 9.5) points less than expected on the CS, p = 0.007, after allowing for age and gender. We believe that the surgeon should discuss with the patient whether a 5.5 points lower score is enough of a difference to warrant a formal rotator cuff repair rather than debridement and SAD alone, and a joint decision should be made.

The NHS Plan (2000) identified the need for change in the way patients are asked to give consent for surgery to make the process more explicit. A new NHS operation consent form was introduced in April 2002 following the Bristol enquiry into deaths associated with Cardiac Surgery.

Methods: We have addressed the obtaining of consent for surgery as an evidence-based exercise. The published literature has been reviewed and we have attempted to accurately quantify the success rates for surgery, complication rates and poor outcomes in order to identify what the likely benefits and risks are for our common operations –

Shoulder – Arthroscopic Sub-Acromial Decompression, Anterior stabilisation, Rotator Cuff repair, excision lateral end of clavicle and Shoulder Arthroplasty.

Evidence was therefore been categorised into 4 levels:

National & International published results

Results: We have taken the standard NHS Consent Form and modified it in a printed format to present to the patient a clearer description of the anticipated outcome from their surgery (with percentages). This evidence based consent form was evaluated in a combined prospective and retrospective survey of 60 patients who attended our pre-operative assessment clinic. We will present the results of the survey and demonstrate the standardised Consent Forms.

Conclusions: The majority of the information the patient wished to know was Level 4 evidence!

Background: Instability of the Sterno-Clavicular Joint (SCJ) can occur due to indirect trauma or ligament laxity. Reconstruction of unstable SCJs has focussed on extra-articular procedures aimed at either holding the medial clavicle downwards or backwards (for anterior subluxation), and often attempting to re-create the Costo-Clavicular CC ligament effect.

Methods: Experience of clinical traumatic injuries where the intra-articular meniscus of the SCJ was disrupted has highlighted the importance of this structure in stabilising the SCJ. This meniscus, through its attachments to the sternum medially and the clavicle laterally, may have a greater effect on the stability of the joint than previously realised – much greater than the stabilising effect of the CC ligament. Anatomical studies of the intra-articular disc, its attachments and the effect of dividing the CC ligament have been carried out on anatomical and fresh frozen cadaver specimens.

Results: Division of the CC ligament alone has only a small effect on SCJ stability. However division of the SCJ disc with the CC still intact has a significant effect on SCJ stability. It is now suspected that patients with joint laxity associated with SCJ anterior subluxation have pathology affecting the SCJ disc and this will be described. An embroidered polyester SCJ augmentation device has been designed to re-create the stabilising forces initially generated by the SCJ disc before stretching or tearing has occurred. This device has been designed to be inserted within the SCJ disc (if present) and anchored to the sternum and clavicle using screws with a technique that recreates stability to the joint. The biomechanics of this reconstruction with pictorial demonstrations of the effect of this stabiliser will be described.

Discussion: Our understanding of the stabilising structures of the SCJ is only now becoming clearer. With this knowledge, improved methods of managing SCJ problems may now be developed.

Background: The Delta Inverse Shoulder Arthroplasty, has gained considerable popularity in France and Europe for Rotator Cuff (RC) deficient patients. However complications related to surgical difficulties with insertion, mechanical loosening, and polyethylene (PE) wear are now being reported. The increasing numbers of complications are alarming.

Methods: A computerised analysis of the kinematics associated with inverse shoulder replacements has been developed. Different glenoid dome sizes and humeral cup dimensions have been tested. This has highlighted the deficiencies associated with the design of the inverse shoulder prostheses currently available on the market. Modifications of the prosthesis geometry and the inclusion of a mobile bearing have also been subjected to computer analysis and have demonstrated improved kinematics and a reduction in the risk of bone/prosthesis contact. A medium term follow-up of 9 patients with a mobile bearing Inverse shoulder design has been carried out. Compression tests have been carried out on the PE bearing to identify the risk of plastic deformity of the PE.

Results: The results of the computerised analysis and the clinical results from the first 9 patients will be reported. One patient suffered an operative complication with failure of reduction of the prosthesis which was rectified at an immediate re-operation. The early clinical results are similar to the good results obtained with the Delta prosthesis. However polyethylene bearing failure has occurred in one case, highlighting the importance of optimising the geometry of the inverse shoulder. Both Radio-Stereometric Analyses (RSA) and prospective randomised studies comparing this Inverse prosthesis with either a Cuff Tear Arthropathy (CTA) hemiarthroplasty designes (when Gleno-Humeral(GH) OA is present) or with cuff reconstruction using augmentation (when no GH OA is present) have been designed and will be discussed.

We report the results of a method of reconstructing massive rotator cuff (RC) tears and reinforcing the repaired RC tendons with re-tensioning of the cuff to effect reconstruction of tears which were previously considered non-repairable.

Methods A consecutive series of 37 patients (19 men) with a mean age of 61 years (range 45–80) are reported. Mean duration of pre-op symptoms was 19 (4–36) months and the mean pre-op Constant Score (CS) was 41. Insertion involved anchoring the device to the undersurface of the retracted RC tendon with Ethibond sutures, passing the other end of the device through a tunnel under the greater tuberosity and anchoring the device, under tension, to the proximal humerus with 1 or 2 screws. The proximal fixation is similar to “spot-welding” while the distal fixation is a “flexible plate” fixation.

Results The follow-up mean CS (minimum 10/12 post-op) was 54. There has been one deep infection. Two had MRI confirmed re-rupture of the RC. One case of a stiff shoulder required manipulation. This embroidered polyester augmentation device is resistant to re-tears and integrates well with medium term re-centering of the humeral head which had been superiorly displaced pre-op.

This study investigates the survival (with gross radiological loosening) rates of prostheses following uncemented Total Shoulder Arthroplasties (TSAs) focusing on the glenoid baseplate fixation.

All uncemented TSAs inserted in one shoulder unit from 1989 to 2001 were entered onto a database prospectively and the patients monitored to death or failure of the implant, resulting in revision surgery. Over 80% of the surviving implants were monitored on sequential radiographs and the radiological loosening rate was observed. 273 TSAs have been monitored – 193 with a porous coated glenoid baseplate and 80 with a hydroxyapatite coating on top of the porous coating.

The Survival rates (%) of the non-HA coated base-plates at 1 to 12 years using the Life Table Method were:- 97, 93, 89, 83, 83, 81, 79, 79, 77, 75, 75 & 75% respectively. The Survival rates for the HA coated glenoid baseplates at 1 to 4 years were 100, 97, 93, & 93% respectively. Failures were predominantly due to mechanical loosening and glenoid disassembly with only 3 cases of infection documented. Thus by 4 years there was a statistically significant improvement in survival of the glenoids. Survival rates were further reduced when radiological loosening was taken into account. The earlier series was analysed to assess the survival of prostheses inserted for RA and OA. The survival rates at 5 & 10 years were 78% & 70% for OA and 96% & 88% for RA.

This Life Table analysis confirms the early benefit from the use of hydroxyapatite coating of the glenoid implant of a TSA. Further improvements, particularly in relation to reducing further the small risk of disassembly are underway.

The ACL-deficient knee demonstrates an increase in both tibial rotation and translation that can lead to progressive degeneration within the knee joint. Functional Knee Braces (FKBs) have often been prescribed as an integral part of treatment programmes for such patients. However, the ability of a FKB to increase the stability of the ACL-deficient knee by controlling tibial translation has yet to be confirmed. In addition the athlete with ACL deficiency frequently asks if he/she can use a treadmill as a safe indoor exercise tool.

A prospective study was carried out on 15 pre-operative ACL-deficient patients and 15 fully matched subjects as controls. A gait analysis study was designed using the CODA mpx30 gait analysis system with electromyography (EMGs). The study was carried out using 3 gait situations - simple level walking and treadmill walking (3.6 km/h) both representing low physical activity and treadmill running (10 km/h) representing high physical activity. The tempero-spatial parameters, total range of motion (ROM), joint positions and EMGs were recorded with and without the FKB and the results were compared with the baseline data of both the patients and the data derived from the control subjects.

ACL-deficient subjects had significantly lower speed, shorter stride length and consequently longer double support time while walking on level ground (p< 0.05). None of these variables changed following bracing. The ACL-deficient subjects showed more knee flexion at heel strike and mid-stance which was assumed to be a compensatory reaction to the ligament deficient knee. The FKB significantly reduced ROM in the ACL-deficient subjects at all gait activity levels (p< 0.05). It also reduced peak knee flexion during swing while walking on level ground, but increased maximum knee flexion in swing while walking on the treadmill. Walking on the treadmill reduced hip ROM but running on the treadmill increased ankle ROM in both groups of subjects. No significant angulatory kinematic changes were found during running on the treadmill either before or after bracing. The ACL-deficient subjects showed more knee rotation than the controls during all the trials. Neither the quadriceps nor hamstring muscles showed significant differences between the ACL-deficient and control subjects. The gastrocnemius muscle however was found to have a principal role in the ACL-deficient subjects. FKBs caused the gastrocnemius to be activated earlier (P=0.0001) and showed a positive effect during low force activities. As treadmill walking or running was always accompanied by an increased ankle plantar flexion, it always decreased the gastrocnemius onset activation time that may be a compensatory reaction to stabilise the injured knee. No significant differences were found between the ACL-deficient and the control subjects in terms of kinematics or EMG findings during running on the treadmill.

We have identified beneficial biomechanical changes following the use of FKBs on ACL-deficient knees but only during walking trials. The brace was as effective for walking on the treadmill as walking on the ground. The FKBs led the deficient knees into a safer kinematics and EMG pattern. The ACL-deficient subjects ran as normally as the control subjects and no effects of the FKBs were found during running in our studies.

The aimof this study was to assess proprioception in multi-directional instability of the shoulder before and after a new surgical treatment.

A cross-sectional pilot study assessing shoulder proprioception in asymptomatic controls (n=6), pre-operative patients (n=7) awaiting surgery for atraumatic, multidirectional instability having failed a comprehensive rehabilitation programme and post-operative patients (n=7) having undergone thermo-capsular shrinkage of the shoulder and post-operative rehabilitation. Data were obtained using the Proprioception Assessment System developed at this centre following a standardised protocol to record both threshold to detection of passive movement (TTDPM) and reproduction of passive position (RPP) in three positions of rotation. Means and standard deviations are presented.

There were no differences between shoulders in controls and post-operative patients. Despite the small numbers, pre-operative patients showed significant differences (p< 0.05) between shoulders in 2 of the 6 test protocols. Post-operative shoulders had means similar to controls suggesting thermo-capsular shrinkage may help regain shoulder proprioception after injury.