We hypothesised that a large acromial cover with an upwardly tilted glenoid fossa would be associated with degenerative rotator cuff tears (RCTs), and conversely, that a short acromion with an inferiorly inclined glenoid would be associated with glenohumeral osteoarthritis (OA). This hypothesis was tested using a new radiological parameter, the critical shoulder angle (CSA), which combines the measurements of inclination of the glenoid and the lateral extension of the acromion (the acromion index).

The CSA was measured on standardised radiographs of three groups: 1) a control group of 94 asymptomatic shoulders with normal rotator cuffs and no OA; 2) a group of 102 shoulders with MRI-documented full-thickness RCTs without OA; and 3) a group of 102 shoulders with primary OA and no RCTs noted during total shoulder replacement. The mean CSA was 33.1° (26.8° to 38.6°) in the control group, 38.0° (29.5° to 43.5°) in the RCT group and 28.1° (18.6° to 35.8°) in the OA group. Of patients with a CSA > 35°, 84% were in the RCT group and of those with a CSA < 30°, 93% were in the OA group.

We therefore concluded that primary glenohumeral OA is associated with significantly smaller degenerative RCTs with significantly larger CSAs than asymptomatic shoulders without these pathologies. These findings suggest that individual quantitative anatomy may imply biomechanics that are likely to induce specific types of degenerative joint disorders.

Cite this article: Bone Joint J 2013;95-B:935–41.

Objectives

Cadaveric models of the shoulder evaluate discrete motion segments using the glenohumeral joint in isolation over a defined trajectory. The aim of this study was to design, manufacture and validate a robotic system to accurately create three-dimensional movement of the upper body and capture it using high-speed motion cameras.

The results of proximal humeral replacement following trauma are substantially worse than for osteoarthritis or rheumatoid arthritis. The stable reattachment of the lesser and greater tuberosity fragments to the rotator cuff and the restoration of shoulder biomechanics are difficult. In 1992 we developed a prosthesis designed to improve fixation of the tuberosity fragments in comminuted fractures of the proximal humerus. The implant enables fixation of the fragments to the shaft of the prosthesis and the diaphyseal fragment using screws, washers and a special toothed plate. Between 1992 and 2003 we used this technique in 50 of 76 patients referred to our institution for shoulder reconstruction after trauma. In the remaining 26, reconstruction with a prosthesis and nonabsorbable sutures was performed, as the tuberosity fragments were too small and too severely damaged to allow the use of screws and the toothed plate. The Constant score two years post-operatively was a mean of 12 points better in the acute trauma group and 11 points better in the late post-traumatic group than in the classical suture group. We recommend this technique in patients where the tuberosity fragments are large enough to allow fixation with screws, washers and a toothed plate

Objectives

The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration.

Aims

In patients with a rotator cuff tear, tear pattern and tendon involvement are known risk factors for the development of pseudoparalysis of the shoulder. It remains unclear, however, why similar tears often have very different functional consequences. The present study hypothesizes that individual shoulder anatomy, specifically the moment arms (MAs) of the rotator cuff (RC) and the deltoid muscle, as well as their relative recruitment during shoulder abduction, plays a central role in pseudoparalysis.

The August 2015 Trauma Roundup³⁶⁰ looks at: Thromboprophylaxis not required in lower limb fractures; Subclinical thyroid dysfunction and fracture risk: moving the boundaries in fracture; Posterior wall fractures refined; Neurological injury and acetabular fracture surgery; Posterior tibial plateau fixation; Tibial plateau fractures in the longer term; Comprehensive orthogeriatric care and hip fracture; Compartment syndrome: in the eye of the beholder?

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.