Scapulothoracic fusion (STF) for painful winging
of the scapula in neuromuscular disorders can provide effective pain
relief and functional improvement, but there is little information
comparing outcomes between patients with dystrophic and non-dystrophic
conditions. We performed a retrospective review of 42 STFs in 34
patients with dystrophic and non-dystrophic conditions using a multifilament
trans-scapular, subcostal cable technique supported by a dorsal
one-third semi-tubular plate. There were 16 males and 18 females
with a mean age of 30 years (15 to 75) and a mean follow-up of 5.0
years (2.0 to 10.6). The mean Oxford shoulder score improved from
20 (4 to 39) to 31 (4 to 48). Patients with non-dystrophic conditions
had lower overall functional scores but achieved greater improvements
following STF. The mean active forward elevation increased from
59° (20° to 90°) to 97° (30° to 150°), and abduction from 51° (10°
to 90°) to 83° (30° to 130°) with a greater range of movement achieved
in the dystrophic group. Revision fusion for nonunion was undertaken
in five patients at a mean time of 17 months (7 to 31) and two required
revision for fracture. There were three pneumothoraces, two rib
fractures, three pleural effusions and six nonunions. The main risk
factors for nonunion were smoking, age and previous shoulder girdle surgery. STF is a salvage procedure that can provide good patient satisfaction
in 82% of patients with both dystrophic and non-dystrophic pathologies,
but there was a relatively high failure rate (26%) when poor outcomes
were analysed. Overall function was better in patients with dystrophic
conditions which correlated with better range of movement; however,
patients with non-dystrophic conditions achieved greater functional
improvement.
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 compared the quantitative electromyographic activity of the elbow flexors during four exercises (forced inspiration, forced expiration, trunk flexion and attempted elbow flexion), following intercostal nerve transfer to the musculocutaneous nerve in 32 patients who had sustained root avulsion brachial plexus injuries. Quantitative electromyographic evaluation of the mean and maximum amplitude was repeated three times for each exercise. We found that mean and maximum elbow flexor activity was highest during trunk flexion, followed by attempted elbow flexion, forced inspiration and finally forced expiration. The difference between each group was significant (p <
0.001), with the exception of the difference between trunk flexion and attempted elbow flexion. Consequently, we recommend trunk flexion exercises to aid rehabilitation following intercostal nerve transfer.