The sternoclavicular joint (SCJ) is a pivotal articulation in the linked system of the upper limb girdle, providing load-bearing in compression while resisting displacement in tension or distraction at the manubrium sterni. The SCJ and acromioclavicular joint (ACJ) both have a small surface area of contact protected by an intra-articular fibrocartilaginous disc and are supported by strong extrinsic and intrinsic capsular ligaments. The function of load-sharing in the upper limb by bulky periscapular and thoracobrachial muscles is extremely important to the longevity of both joints. Ligamentous and capsular laxity changes with age, exposing both joints to greater strain, which may explain the rising incidence of arthritis in both with age. The incidence of arthritis in the SCJ is less than that in the ACJ, suggesting that the extrinsic ligaments of the SCJ provide greater stability than the coracoclavicular ligaments of the ACJ.

Instability of the SCJ is rare and can be difficult to distinguish from medial clavicular physeal or metaphyseal fracture-separation: cross-sectional imaging is often required. The distinction is important because the treatment options and outcomes of treatment are dissimilar, whereas the treatment and outcomes of ACJ separation and fracture of the lateral clavicle can be similar. Proper recognition and treatment of traumatic instability is vital as these injuries may be life-threatening. Instability of the SCJ does not always require surgical intervention. An accurate diagnosis is required before surgery can be considered, and we recommend the use of the Stanmore instability triangle. Most poor outcomes result from a failure to recognise the underlying pathology.

There is a natural reluctance for orthopaedic surgeons to operate in this area owing to unfamiliarity with, and the close proximity of, the related vascular structures, but the interposed sternohyoid and sternothyroid muscles are rarely injured and provide a clear boundary to the medial retroclavicular space, as well as an anatomical barrier to unsafe intervention.

This review presents current concepts of instability of the SCJ, describes the relevant surgical anatomy, provides a framework for diagnosis and management, including physiotherapy, and discusses the technical challenges of operative intervention.

Cite this article: Bone Joint J 2013;95-B:721–31.

We assessed the short- to mid-term survival of metallic press-fit radial head prostheses in patients with radial head fractures and acute traumatic instability of the elbow.

The medical records of 42 patients (16 males, 26 females) with a mean age of 56 years (23 to 85) with acute unstable elbow injuries, including a fracture of the radial head requiring metallic replacement of the radial head, were reviewed retrospectively. Survival of the prosthesis was assessed from the radiographs of 37 patients after a mean follow-up of 50 months (12 to 107). The functional results of 31 patients were assessed using range-of-movement, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH) score and the RAND 36-item health survey.

At the most recent follow-up 25 prostheses were still well fixed, nine had been removed because of loosening, and three remained implanted but were loose. The mean time from implantation to loosening was 11 months (2 to 24). Radiolucent lines that developed around the prosthesis before removal were mild in three patients, moderate in one and severe in five. Range of movement parameters and mass grip strength were significantly lower in the affected elbow than in the unaffected side. The mean MEPS score was 86 (40 to 100) and the mean DASH score was 23 (0 to 81). According to RAND-36 scores, patients had more pain and lower physical function scores than normal population values.

Loosening of press-fit radial head prostheses is common, occurs early, often leads to severe osteolysis of the proximal radius, and commonly requires removal of the prosthesis.

The zona conoidea comprises the area of the lateral trochlear ridge of the humerus. The purpose of this study is to reintroduce this term ‘zona conoidea’ to the discussion of the human elbow and to investigate its significance in the development of osteoarthritis of the elbow.

The upper extremities of 12 cadavers were prepared. With the forearm in neutral, pronation and supination, the distance between the bevel of the radial head and zona conoidea was inspected. A total of 12 healthy volunteers had a CT scan. The distance between the zona conoidea and the bevelled rim of the radial head was measured in these positions.

In the anatomical specimens, early osteo-arthritic changes were identified in the posteromedial bevelled rim of the radial head, and the corresponding zona conoidea in supination. Measurement in the CT study showed that in full supination, the distance between the bevel of the radial head and the zona conoidea was at a minimum.

This study suggests that the significant contact between the bevel of the radial head and the zona conoidea in supination is associated with the initiation of osteoarthritis of the elbow in this area.

We investigated the clinical response to arthroscopic synovectomy in patients with undifferentiated chronic monoarthritis (UCMA) of the wrist. Arthroscopic synovectomy was performed on 20 wrists in 20 patients with UCMA of the wrist who had not responded to non-steroidal anti-inflammatory drugs. The mean duration of symptoms at the time of surgery was 4.3 months (3 to 7) and the mean follow-up was 51.8 months (24 to 94). Inflamed synovium was completely removed from the radiocarpal, midcarpal and distal radioulnar joints using more portals than normal. After surgery, nine patients had early remission of synovitis and 11 with uncontrolled synovitis received antirheumatic medication. Overall, there was significant improvement in terms of pain relief, range of movement and Mayo score. Radiological deterioration was seen in five patients who were diagnosed as having rheumatoid arthritis during the follow-up period. Lymphoid follicles and severe lymphocyte infiltration were seen more often in synovial biopsies from patients with uncontrolled synovitis.

These results suggest that arthroscopic synovectomy provides pain relief and functional improvement, and allows rapid resolution of synovitis in about half of patients with UCMA of the wrist.

Radiological changes and differences between cemented and uncemented components of Grammont reverse shoulder arthroplasties (DePuy) were analysed at a mean follow-up of 9.6 years (8 to 12). Of 122 reverse shoulder arthroplasties implanted in five shoulder centres between 1993 and 2000, a total of 68 (65 patients) were available for study. The indications for reversed shoulder arthroplasty were cuff tear arthropathy in 48 shoulders, revision of shoulder prostheses of various types in 11 and massive cuff tear in nine. The development of scapular notching, bony scapular spur formation, heterotopic ossification, glenoid and humeral radiolucencies, stem subsidence, radiological signs of stress shielding and resorption of the tuberosities were assessed on standardised true anteroposterior and axillary radiographs.

A scapular notch was observed in 60 shoulders (88%) and was associated with the superolateral approach (p = 0.009). Glenoid radiolucency was present in 11 (16%), bony scapular spur and/or ossifications in 51 (75%), and subsidence of the stem and humeral radiolucency in more than three zones were present in three (8.8%) and in four (11.8%) of 34 cemented components, respectively, and in one (2.9%) and two (5.9%) of 34 uncemented components, respectively. Radiological signs of stress shielding were significantly more frequent with uncemented components (p < 0.001), as was resorption of the greater (p < 0.001) and lesser tuberosities (p = 0.009).

The combination of an irreparable tear of the rotator cuff and destructive arthritis of the shoulder joint may cause severe pain, disability and loss of independence in the aged. Standard anatomical shoulder replacements depend on a functioning rotator cuff, and hence may fail in the presence of tears in the cuff. Many designs of non-anatomical constrained or semi-constrained prostheses have been developed for cuff tear arthropathy, but have proved unsatisfactory and were abandoned. The DePuy Delta III reverse prosthesis, designed by Grammont, medialises and stabilises the centre of rotation of the shoulder joint and has shown early promise. This study evaluated the mid-term clinical and radiological results of this arthroplasty in a consecutive series of 50 shoulders in 43 patients with a painful pseudoparalysis due to an irreparable cuff tear and destructive arthritis, performed over a period of seven years by a single surgeon. A follow-up of 98% was achieved, with a mean duration of 39 months (8 to 81). The mean age of the patients at the time of surgery was 81 years (59 to 95). The female to male ratio was 5:1. During the seven years, six patients died of natural causes. The clinical outcome was assessed using the American Shoulder and Elbow score, the Oxford Shoulder Score and the Short-form 36 score. A radiological review was performed using the Sirveaux score for scapular notching.

The mean American Shoulder and Elbow score was 19 (95% confidence interval (CI) 14 to 23) pre-operatively, and 65 (95% CI 48 to 82) (paired t-test, p < 0.001) at final follow-up. The mean Oxford score was 44 (95% CI 40 to 51) pre-operatively and 23 (95% CI 18 to 28) (paired t-test, p < 0.001) at final follow-up.

The mean maximum elevation improved from 55° pre-operatively to 105° at final follow-up. There were seven complications during the whole series, although only four patients required further surgery.

We have previously described the short-term outcome of the use of reverse shoulder arthroplasty in the treatment of acute complex proximal humeral fractures in the elderly. We now report the clinical and radiological outcome of 36 fractures at a mean of 6.6 years (1 to 16). Previously, at a mean follow-up of 6 years (1 to 12) the mean Constant score was 58.5; this was reduced to 53 points with the further follow-up. A total of 23 patients (63%) had radiological evidence of loosening of the glenoid component. Nevertheless, only one patient had aseptic loosening of the baseplate at 12 years’ follow-up.

The reduction in the mean Constant score with longer follow-up and the further development of scapular notching is worrying.

New developments in design, bearing surfaces and surgical technique, and further follow-up, will determine whether reverse shoulder arthroplasty has a place in the management of complex proximal humeral fractures in the elderly.

We reviewed the outcome of 28 patients who had been treated using the Aequalis fracture prosthesis for an acute fracture of the proximal humerus at a mean follow-up of 39.3 months (24 to 63). The mean age of the patients at the time of the fracture was 66.3 years (38 to 80). The mean Constant score was 68.2 (37 to 84) for the operated shoulder, which represented 89.5% of the mean score for the uninjured side (p < 0.001). The quality of the reconstruction as shown on the immediate post-operative radiographs was categorised into three types, anatomical, acceptable, and unacceptable, depending on the position of the tuberosities relative to the prosthetic head and the humeral shaft. Anatomical reconstruction was associated with a higher mean Constant score as well as higher mean values of anterior forward elevation, abduction and external rotation than the other types, but the differences were not statistically significant (p > 0.231).

A total of 18 patients had active anterior elevation ≥150°. Their mean active abduction and external rotation were 163.6° and 31.3°, respectively. In seven of the 28 patients, the mean active anterior elevation, abduction and external rotation were 130.7°, 129.2° and 22.8°, respectively. In all, 12 patients were very satisfied with the results, 12 were satisfied, two were dissatisfied and two were disappointed; 26 reported no or only mild pain while only two had moderate pain. In five patients proximal migration of the humeral head was shown on the anteroposterior radiographs of the shoulder. No evidence of loosening was found in any prosthesis.

In a prospective study between 2000 and 2005, 22 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with a standard five-pegged glenoid component, 12 with non-offset humeral head and ten with offset humeral head components. Over a period of 24 months the relative movement of the glenoid component with respect to the scapula was measured using radiostereometric analysis.

Nine glenoids needed reaming for erosion. There was a significant increase in rotation about all three axes with time (p < 0.001), the largest occurring about the longitudinal axis (anteversion-retroversion), with mean values of 3.8° and 1.9° for the non-offset and offset humeral head eroded subgroups, respectively. There was also a significant difference in rotation about the anteversion-retroversion axis (p = 0.01) and the varus-valgus (p < 0.001) z-axis between the two groups. The offset humeral head group reached a plateau at early follow-up with rotation about the z-axis, whereas the mean of the non-offset humeral head group at 24 months was three times greater than that of the offset group accounting for the highly significant difference between them.

Reversed shoulder prostheses are increasingly being used for the treatment of glenohumeral arthropathy associated with a deficient rotator cuff. These non-anatomical implants attempt to balance the joint forces by means of a semi-constrained articular surface and a medialised centre of rotation. A finite element model was used to compare a reversed prosthesis with an anatomical implant. Active abduction was simulated from 0° to 150° of elevation. With the anatomical prosthesis, the joint force almost reached the equivalence of body weight. The joint force was half this for the reversed prosthesis. The direction of force was much more vertically aligned for the reverse prosthesis, in the first 90° of abduction. With the reversed prosthesis, abduction was possible without rotator cuff muscles and required 20% less deltoid force to achieve it.

This force analysis confirms the potential mechanical advantage of reversed prostheses when rotator cuff muscles are deficient.

We have undertaken a prospective clinical and radiological analysis of 124 shoulder arthroplasties (113 patients) carried out for osteoarthritis. The clinical results showed improvement in the absolute Constant score and the American Shoulder and Elbow Surgeons score of 22 and 43, respectively. Both were statistically significant (p < 0.001). There was no significant difference in the scores after hemiarthroplasty and total arthroplasty in those patients with an intact rotator cuff.

When revision was used as the end-point for survival at ten years, survival of 86%, or 90% if glenoid components made of Hylamer sterilised in air were omitted, was obtained in primary osteoarthritis. The most common cause for revision in the hemiarthroplasty group was glenoid pain at a mean of 1.5 years; in the total arthroplasty group it was loosening of the glenoid at a mean of 4.5 years. Analysis of pre-operative factors showed that the risk of gross loosening of the glenoid increased threefold when there was evidence of erosion of the glenoid at operation. Shoulder arthroplasty should not be delayed once symptomatic osteoarthritis has been established and should be undertaken before failure of the cuff or erosion of the glenoid are present.

Replacement of the shoulder in juvenile idiopathic arthritis is not often performed and there have been no published series to date.

We present nine glenohumeral hemiarthroplasties in eight patients with systemic or polyarticular juvenile idiopathic arthritis. The mean follow-up was six years (59 to 89 months). The mean age at the time of surgery was 32 years. Surgery took place at a mean of 27 years after diagnosis. The results indicated excellent relief from pain. There was restoration of useful function which deteriorated with time, in part because of progression of the systemic disease in this severely affected group. No patient has required revision to date and there has been no radiological evidence of loosening or osteolysis around the implants.

We discuss the pathoanatomical challenges unique to this group. There was very little space for a prosthetic joint and, in some cases, bony deformity and the small size necessitated the use of custom-made implants.