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.
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:
Contracture of the collateral ligaments is considered to be an important factor in post-traumatic stiffness of the elbow. We reviewed the results of isolated release of the medial collateral ligament in a series of 14 patients with post-traumatic loss of elbow flexion treated between 1998 and 2002. There were nine women and five men with a mean age of 45 years (17 to 76). They were reviewed at a mean follow-up of 25 months (9 to 48). The operation was performed through a longitudinal posteromedial incision centred over the ulnar nerve. After decompression of the ulnar nerve, release of the medial collateral ligament was done sequentially starting with the posterior bundle and the transverse component of the ligament, with measurement of the arc of movement after each step. If full flexion was not achieved the posterior half of the anterior bundle of the medial collateral ligament was released. At the latest follow-up, the mean flexion of the elbow improved significantly from 96° (85° to 115°) pre-operatively to 130° (110° to 150°) at final follow-up (p = 0.001). The mean extension improved significantly from 43° (5° to 90°) pre-operatively to 22° (5° to 40°) at final follow-up (p = 0.003). There was a significant improvement in the functional outcome. The mean Broberg and Morrey score increased from a mean of 54 points (29.5 to 85) pre-operatively to 87 points (57 to 99) at final follow-up (p <
0.001). All the patients had normal elbow stability. Our results indicate that partial surgical release of the medial collateral ligament is associated with improved range of movement of the elbow in patients with post-traumatic stiffness, but was less effective in controlling pain.
We compared the outcome of peri-operative humeral condylar fractures in patients undergoing a Coonrad-Morrey semiconstrained total elbow replacement with that of patients with rheumatoid arthritis undergoing the same procedure without fractures. In a consecutive series of 40 elbows in 33 patients, 13 elbows had a fracture in either condyle peri-operatively, and 27 elbows were intact. The fractured condyle was either fixed internally or excised. We found no statistical difference in the patients’ background, such as age, length of follow-up, immobilisation period, Larsen’s radiological grade, or Steinbrocker’s stage and functional class. There was also no statistical difference between the groups in relation to the Mayo Elbow Performance Score, muscle strength, range of movement, or radiolucency around the implants at a mean of 4.8 years (1.1 to 8.0) follow-up. We conclude that fractured condyles can be successfully treated with either internal fixation or excision, and cause no harmful effect.
