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
Reverse total shoulder replacement (RTSR) depends
on adequate deltoid function for a successful outcome. However, the
anterior deltoid and/or axillary nerve may be damaged due to prior
procedures or injury. The purpose of this study was to determine
the compensatory muscle forces required for scapular plane elevation
following RTSR when the anterior deltoid is deficient. The soft
tissues were removed from six cadaver shoulders, except for tendon
attachments. After implantation of the RTSR, the shoulders were
mounted on a custom-made shoulder simulator to determine the mean
force in each muscle required to achieve 30° and 60° of scapular
plane elevation. Two conditions were tested: 1) Control with an
absent supraspinatus and infraspinatus; and 2) Control with anterior
deltoid deficiency. Anterior deltoid deficiency resulted in a mean
increase of 195% in subscapularis force at 30° when compared with
the control (p = 0.02). At 60°, the subscapularis force increased
a mean of 82% (p <
0.001) and the middle deltoid force increased
a mean of 26% (p = 0.04). Scapular plane elevation may still be possible following an RTSR
in the setting of anterior deltoid deficiency. When the anterior
deltoid is deficient, there is a compensatory increase in the force
required by the subscapularis and middle deltoid. Attempts to preserve
the subscapularis, if present, might maximise post-operative function.
There is little information about the management
of peri-prosthetic fracture of the humerus after total shoulder replacement
(TSR). This is a retrospective review of 22 patients who underwent
a revision of their original shoulder replacement for peri-prosthetic
fracture of the humerus with bone loss and/or loose components.
There were 20 women and two men with a mean age of 75 years (61
to 90) and a mean follow-up 42 months (12 to 91): 16 of these had
undergone a previous revision TSR. Of the 22 patients, 12 were treated
with a long-stemmed humeral component that bypassed the fracture.
All their fractures united after a mean of 27 weeks (13 to 94).
Eight patients underwent resection of the proximal humerus with
endoprosthetic replacement to the level of the fracture. Two patients
were managed with a clam-shell prosthesis that retained the original
components. The mean Oxford shoulder score (OSS) of the original
TSRs before peri-prosthetic fracture was 33 (14 to 48). The mean
OSS after revision for fracture was 25 (9 to 31). Kaplan-Meier survival
using re-intervention for any reason as the endpoint was 91% (95%
confidence interval (CI) 68 to 98) and 60% (95% CI 30 to 80) at
one and five years, respectively. There were two revisions for dislocation of the humeral head,
one open reduction for modular humeral component dissociation, one
internal fixation for nonunion, one trimming of a prominent screw
and one re-cementation for aseptic loosening complicated by infection,
ultimately requiring excision arthroplasty. Two patients sustained
nerve palsies. Revision TSR after a peri-prosthetic humeral fracture associated
with bone loss and/or loose components is a salvage procedure that
can provide a stable platform for elbow and hand function. Good
rates of union can be achieved using a stem that bypasses the fracture.
There is a high rate of complications and function is not as good as
with the original replacement.
We prospectively studied 26 consecutive patients with clinically documented sensory or motor deficiency of a peripheral nerve due to trauma or entrapment using ultrasound, and in 19 cases surgical exploration of the nerves was undertaken. The ultrasonographic diagnoses were correlated with neurological examination and the surgical findings. Reliable visualisation of injured nerves on ultrasonography was achieved in all patients. Axonal swelling and hypoechogenity of the nerve was diagnosed in 15 cases, loss of continuity of a nerve bundle in 17, the formation of a neuroma of a stump in six, and partial laceration of a nerve with loss of the normal fascicular pattern in five. The ultrasonographic findings were confirmed at operation in those who had surgery. Ultrasound may be used for the evaluation of peripheral nerve injuries in the upper limb. High-resolution ultrasound can show the exact location, extent and type of lesion, yielding important information that might not be obtainable by other diagnostic aids.
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.