The outcome of an anatomical shoulder replacement
depends on an intact rotator cuff. In 1981 Grammont designed a novel
large-head
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
Instability after arthroplasty of the shoulder
is difficult to correct surgically. Soft-tissue procedures and revision surgery
using unconstrained anatomical components are associated with a
high rate of failure. The purpose of this study was to determine
the results of revision of an unstable anatomical shoulder arthroplasty
to a
We have previously described the short-term outcome of the use of
Radiological changes and differences between cemented and uncemented components of Grammont
We report the use of the
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
We retrospectively reviewed 21 patients (22 shoulders) who presented with deep infection after surgery to the shoulder, 17 having previously undergone hemiarthroplasty and five open repair of the rotator cuff. Nine shoulders had undergone previous surgical attempts to eradicate their infection. The diagnosis of infection was based on a combination of clinical suspicion (16 shoulders), positive frozen sections (>
5 polymorphonuclear leukocytes per high-power field) at the time of revision (15 shoulders), positive intra-operative cultures (18 shoulders) or the pre-operative radiological appearances. The patients were treated by an extensive debridement, intravenous antibiotics, and conversion to a
This study provides recommendations on the position
of the implant in
There have been only a few small studies of patients
with an infected shoulder replacement treated with a single-stage
exchange procedure. We retrospectively reviewed 35 patients (19 men
and 16 women) with a peri-prosthetic infection of the shoulder who
were treated in this way. A total of 26 were available for clinical
examination; three had died, two were lost to follow-up and four
patients had undergone revision surgery. The mean follow-up time was
4.7 years (1.1 to 13.25), with an infection-free survival of 94%. The organisms most commonly isolated intra-operatively were Staphylococcus
epidermidis and Propionibacterium acnes;
two patients developed a recurrent infection. Three different types
of prosthesis were used: a hemiarthroplasty, a hemiarthroplasty
with a bipolar head and
The optimal choice of management for proximal humerus fractures (PHFs) has been increasingly discussed in the literature, and this work aimed to answer the following questions: 1) what are the incidence rates of PHF in the geriatric population in the USA; 2) what is the mortality rate after PHF in the elderly population, specifically for distinct treatment procedures; and 3) what factors influence the mortality rate? PHFs occurring between 1 January 2009 and 31 December 2019 were identified from the Medicare physician service records. Incidence rates were determined, mortality rates were calculated, and semiparametric Cox regression was applied, incorporating 23 demographic, clinical, and socioeconomic covariates, to compare the mortality risk between treatments.Aims
Methods
Rotator cuff tear (RCT) is the leading cause of shoulder pain, primarily associated with age-related tendon degeneration. This study aimed to elucidate the potential differential gene expressions in tendons across different age groups, and to investigate their roles in tendon degeneration. Linear regression and differential expression (DE) analyses were performed on two transcriptome profiling datasets of torn supraspinatus tendons to identify age-related genes. Subsequent functional analyses were conducted on these candidate genes to explore their potential roles in tendon ageing. Additionally, a secondary DE analysis was performed on candidate genes by comparing their expressions between lesioned and normal tendons to explore their correlations with RCTs.Aims
Methods
Rotator cuff muscle atrophy and fatty infiltration affect the clinical outcomes of rotator cuff tear patients. However, there is no effective treatment for fatty infiltration at this time. High-intensity interval training (HIIT) helps to activate beige adipose tissue. The goal of this study was to test the role of HIIT in improving muscle quality in a rotator cuff tear model via the β3 adrenergic receptor (β3AR). Three-month-old C57BL/6 J mice underwent a unilateral rotator cuff injury procedure. Mice were forced to run on a treadmill with the HIIT programme during the first to sixth weeks or seventh to 12th weeks after tendon tear surgery. To study the role of β3AR, SR59230A, a selective β3AR antagonist, was administered to mice ten minutes before each exercise through intraperitoneal injection. Supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat were harvested at the end of the 12th week after tendon tear and analyzed biomechanically, histologically, and biochemically.Aims
Methods
This study aimed to define the histopathology of degenerated humeral head cartilage and synovial inflammation of the glenohumeral joint in patients with omarthrosis (OmA) and cuff tear arthropathy (CTA). Additionally, the potential of immunohistochemical tissue biomarkers in reflecting the degeneration status of humeral head cartilage was evaluated. Specimens of the humeral head and synovial tissue from 12 patients with OmA, seven patients with CTA, and four body donors were processed histologically for examination using different histopathological scores. Osteochondral sections were immunohistochemically stained for collagen type I, collagen type II, collagen neoepitope C1,2C, collagen type X, and osteocalcin, prior to semiquantitative analysis. Matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 levels were analyzed in synovial fluid using enzyme-linked immunosorbent assay (ELISA).Aims
Methods
Rotator cuff (RC) injuries are characterized by tendon rupture, muscle atrophy, retraction, and fatty infiltration, which increase injury severity and jeopardize adequate tendon repair. Epigenetic drugs, such as histone deacetylase inhibitors (HDACis), possess the capacity to redefine the molecular signature of cells, and they may have the potential to inhibit the transformation of the fibro-adipogenic progenitors (FAPs) within the skeletal muscle into adipocyte-like cells, concurrently enhancing the myogenic potential of the satellite cells. HDACis were added to FAPs and satellite cell cultures isolated from mice. The HDACi vorinostat was additionally administered into a RC injury animal model. Histological analysis was carried out on the isolated supra- and infraspinatus muscles to assess vorinostat anti-muscle degeneration potential.Aims
Methods
We retrospectively reviewed 11 consecutive patients with an infected
A
The objective of this study was to perform a meta-analysis of all randomised controlled trials (RCTs) comparing surgical and non-surgical management of fractures of the proximal humerus, and to determine whether further analyses based on complexity of fracture, or the type of surgical intervention, produced disparate findings on patient outcomes. A systematic review of the literature was performed identifying all RCTs that compared surgical and non-surgical management of fractures of the proximal humerus. Meta-analysis of clinical outcomes was performed where possible. Subgroup analysis based on the type of fracture, and a sensitivity analysis based on the type of surgical intervention, were also performed.Objectives
Methods
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.
Fractures of the proximal humerus can lead to malalignment of the humeral head, necrosis and post-traumatic osteoarthritis. In such cases surface replacement might be a promising option. A total of 28 shoulders with glenohumeral arthritis subsequent to a fracture underwent surface replacement arthroplasty of the humeral head in patients with a mean age of 60 years (35 to 83). On the basis of the inclination of the impacted head, post-traumatic arthritis was divided into three types: type 1, an impacted fracture of the head in an anatomical position (seven cases); type 2, a valgus impacted fracture (13 cases); type 3, a varus impacted fracture (eight cases). The outcome was measured by means of the Constant score. According to the Boileau classification of the sequelae of fractures of the proximal humerus, all 28 patients had a final result of intra-capsular category 1. The mean Constant score for the 28 shoulders increased from 23.2 points (2 to 45) pre-operatively to 55.1 points (20 to 89) at a mean of 31 months (24 to 66) post-operatively. Valgus impacted fractures had significantly better results (p <
0.039). Surface replacement arthroplasty can provide good results for patients with post-traumatic osteoarthritis of the shoulder. Their use avoids post-operative complications of the humeral shaft, such as peri-prosthetic fractures. Further surgery can be undertaken more easily as the bone stock is preserved.
Despite the expansion of arthroscopic surgery
of the shoulder, the open deltopectoral approach to the shoulder
is still frequently used, for example in fracture fixation and shoulder
replacement. However, it is sometimes accompanied by unexpected
bleeding. The cephalic vein is the landmark for the deltopectoral
interval, yet its intimate relationship with the deltoid artery,
and the anatomical variations in that structure, have not previously been
documented. In this study the vascular anatomy encountered during 100 consecutive
elective deltopectoral approaches was recorded and the common variants
described. Two common variants of the deltoid artery were encountered.
In type I (71%) it crosses the interval and tunnels into the deltoid
muscle without encountering the cephalic vein. However, in type
II (21%) it crosses the interval, reaches the cephalic vein and
then runs down, medial to and behind it, giving off several small
arterial branches that return back across the interval to the pectoralis
major. Several minor variations were also seen (8%). These variations in the deltoid artery have not previously been
described and may lead to confusion and unexpected bleeding during
this standard anterior surgical approach to the shoulder. Cite this article:
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.
We describe a technique of soft-tissue reconstruction which is effective for the treatment of chronic lunotriquetral instability. Part of extensor carpi ulnaris is harvested with its distal attachment preserved. It is passed through two drill holes in the triquetrum and sutured to itself. This stabilises the ulnar side of the wrist. We have reviewed 46 patients who underwent this procedure for post-traumatic lunotriquetral instability with clinical signs suggestive of ulnar-sided carpal instability. Standard radiographs were normal. All patients had pre-operative arthroscopy of the wrist at which dynamic lunotriquetral instability was demonstrated. A clinical rating system for the wrist by the Mayo clinic was used to measure the outcome. In 19 patients the result was excellent, in ten good, in 11 satisfactory and in six poor. On questioning, 40 (87%) patients said that surgery had substantially improved the condition and that they would recommend the operation. However, six (13%) were unhappy with the outcome and would not undergo the procedure again for a similar problem. There were six complications, five of which related to pisotriquetral problems. The mean follow-up was 39.1 months (6 to 100). We believe that tenodesis of extensor carpi ulnaris is a very satisfactory procedure for isolated, chronic post-traumatic lunotriquetral instability in selected patients. In those with associated pathology, the symptoms were improved, but the results were less predictable.
Bone loss involving articular surface is a challenging
problem faced by the orthopaedic surgeon. In the hand and wrist,
there are articular defects that are amenable to autograft reconstruction
when primary fixation is not possible. In this article, the surgical
techniques and clinical outcomes of articular reconstructions in
the hand and wrist using non-vascularised osteochondral autografts
are reviewed.
Local corticosteroid infiltration is a common practice of treatment
for lateral epicondylitis. In recent studies no statistically significant
or clinically relevant results in favour of corticosteroid injections
were found. The injection of autologous blood has been reported
to be effective for both intermediate and long-term outcomes. It
is hypothesised that blood contains growth factors, which induce
the healing cascade. A total of 60 patients were included in this prospective randomised
study: 30 patients received 2 ml autologous blood drawn from contralateral
upper limb vein + 1 ml 0.5% bupivacaine, and 30 patients received
2 ml local corticosteroid + 1 ml 0.5% bupivacaine at the lateral
epicondyle. Outcome was measured using a pain score and Nirschl
staging of lateral epicondylitis. Follow-up was continued for total
of six months, with assessment at one week, four weeks, 12 weeks
and six months.Objectives
Methods
A total of 159 patients (84 women and 75 men,
mean age of 53 (20 to 87)) with subacromial impingement were randomised
to treatment with subacromial injections using lidocaine with one
of hyaluronic acid (51 patients), corticosteroid (53 patients) or
placebo (55 patients). Patients were followed up for 26 weeks. The
primary outcome was pain on a visual analogue score (VAS), and secondary
outcomes included the Constant Murley score, shoulder pain score,
functional mobility score, shoulder disability questionnaire and
pain-specific disability score. The different outcome measures showed
similar results. After three, six and 12 weeks corticosteroid injections
were superior to hyaluronic acid injections and only at six weeks
significantly better than placebo injections. The mean short-term
reduction in pain on the VAS score at 12 weeks was 7% ( We were not able to show a convincing benefit from hyaluronic
acid injections compared with corticosteroid or placebo injections.
Corticosteroid injections produced a significant reduction in pain
in the short term (three to 12 weeks), but in the long term the
placebo injection produced the best results.
The pathogenesis of rotator cuff disease (RCD) is complex and
not fully understood. This systematic review set out to summarise
the histological and molecular changes that occur throughout the
spectrum of RCD. We conducted a systematic review of the scientific literature
with specific inclusion and exclusion criteria.Introduction
Methods
This study was performed to review the safety and outcome of total shoulder replacements in patients who are ≥ 80 years of age. A total of 50 total shoulder replacements in 44 patients at a mean age of 82 years (80 to 89) were studied. Their health and shoulder status, the operation and post-operative course were analysed, including pain, movement, patient satisfaction, medical and surgical complications, radiographs, the need for revision surgery, and implant and patient survival. A total of 27 patients had an ASA classification of III or IV and medical abnormalities were common. Of the 13 shoulders with bony deficiency of the glenoid, nine required grafting. The duration of hospital stay was prolonged and blood transfusions were common. There were no peri-operative deaths. The mean follow-up was for 5.5 years (2 to 12). Pain was significantly reduced (p <
0.001) and movement improved in active elevation and both external and internal rotation (p <
0.001). Using the Neer scale for assessing outcome, 40 (80%) shoulders had an excellent or satisfactory result. There were medical or surgical complications in 17 cases. Four shoulders developed radiological evidence of loosened glenoid components, and three of these had a poor outcome. Three other shoulders required revision, two for instability. By the time of this review 39 of the patients had died from unrelated causes at a mean of 7.5 years (0.8 to 16.4) after surgery. Total shoulder replacement is a relatively effective treatment in this elderly group of patients. However, there is a requirement for more intense patient care in the peri-operative period, and non-fatal medical or surgical complications are common. Most of these elderly patients will have a comfortable functional shoulder for the rest of their lives.
In a prospective randomised study we compared the results of arthroscopic subacromial bursectomy alone with debridement of the subacromial bursa followed by acromioplasty. A total of 57 patients with a mean age of 47 years (31 to 60) suffering from primary subacromial impingement without a rupture of the rotator cuff who had failed previous conservative treatment were entered into the trial. The type of acromion was classified according to Bigliani. Patients were assessed at follow-up using the Constant score, the simple shoulder test and visual analogue scores for pain and functional impairment. One patient was lost to follow-up. At a mean follow-up of 2.5 years (1 to 5) both bursectomy and acromioplasty gave good clinical results. No statistically significant differences were found between the two treatments. The type of acromion and severity of symptoms had a greater influence on the clinical outcome than the type of treatment. As a result, we believe that primary subacromial impingement syndrome is largely an intrinsic degenerative condition rather than an extrinsic mechanical disorder.
We have investigated the outcome of arthroscopic revision surgery for recurrent instability of the shoulder after failed primary anterior stabilisation. We identified 40 patients with failed primary open or arthroscopic anterior stabilisation of the shoulder who had been treated by revision arthroscopic capsulolabral reconstruction and followed up for a mean of 36 months (12 to 87). There were 34 men and six women with a mean age of 33.1 years (15 to 48). Details of the patients, the technique of the primary procedure, the operative findings at revision and the clinical outcome were evaluated by reviewing the medical records, physical examination and the use of the Western Ontario shoulder instability index score, the American Shoulder and Elbow Surgeons score and the health status questionnaire 12. Recurrent instability persisted in four patients after the revision arthroscopic procedure. At the final follow-up, the mean American Shoulder and Elbow Surgeons score was 81.1 (17.5 to 99.5) and the mean Western Ontario shoulder instability index score was 68.2 (20 to 98.2). Quality-of-life scoring showed good to excellent results in most patients. Arthroscopic revision capsulolabral reconstruction can provide a satisfactory outcome in selected patients for recurrent instability of the shoulder provided that no large Hill-Sachs lesion is present.
While frequently discussed as a standard treatment for the management of an infected shoulder replacement, there is little information on the outcome of two-stage re-implantation. We examined the outcome of 17 consecutive patients (19 shoulders) who were treated between 1995 and 2004 with a two-stage re-implantation for the treatment of a deep-infection after shoulder replacement. All 19 shoulders were followed for a minimum of two years or until the time of further revision surgery. The mean clinical follow-up was for 35 months (24 to 80). The mean radiological follow-up was 27 months (7 to 80). There were two excellent results, four satisfactory and 13 unsatisfactory. In 12 of the 19 shoulders (63%) infection was considered to be eradicated. The mean pain score improved from 4.2 (3 to 5 (out of 5)) to 1.8 (1 to 4). The mean elevation improved from 42° (0° to 140°) to 89° (0° to 165°), mean external rotation from 30° (0° to 90°) to 43° (0° to 90°), and mean internal rotation from the sacrum to L5. There were 14 complications. Our study suggests that two-stage re-implantation for an infected shoulder replacement is associated with a high rate of unsatisfactory results, marginal success at eradicating infection and a high complication rate.
Transfer of pectoralis major has evolved as the most favoured option for the management of the difficult problem of irreparable tears of subscapularis. We describe our experience with this technique in 30 patients divided into three groups. Group I comprised 11 patients with a failed procedure for instability of the shoulder, group II included eight with a failed shoulder replacement and group III, 11 with a massive tear of the rotator cuff. All underwent transfer of the sternal head of pectoralis major to restore the function of subscapularis. At the latest follow-up pain had improved in seven of the 11 patients in groups I and III, but in only one of eight in group II. The subjective shoulder score improved in seven patients in group I, in one in group II and in six in group III. The mean Constant score improved from 40.9 points (28 to 50) in group I, 32.9 (17 to 47) in group II and 28.7 (20 to 42) in group III pre-operatively to 60.8 (28 to 89), 41.9 (24 to 73) and 52.3 (24 to 78), respectively. Failure of the tendon transfer was highest in group II and was associated with pre-operative anterior subluxation of the humeral head. We conclude that in patients with irreparable rupture of subscapularis after shoulder replacement there is a high risk of failure of transfer of p?ctoralis major, particularly if there is pre-operative anterior subluxation of the humeral head.
Residual muscle weakness in obstetric brachial plexus palsy results in soft-tissue contractures which limit the functional range of movement and lead to progressive glenoid dysplasia and joint instability. We describe the results of surgical treatment in 98 patients (mean age 2.5 years, 0.5 to 9.0) for the correction of active abduction of the shoulder. The patients underwent transfer of the latissimus dorsi and teres major muscles, release of contractures of subscapularis pectoralis major and minor, and axillary nerve decompression and neurolysis (the modified Quad procedure). The transferred muscles were sutured to the teres minor muscle, not to a point of bony insertion. The mean pre-operative active abduction was 45° (20° to 90°). At a mean follow-up of 4.8 years (2.0 to 8.7), the mean active abduction was 162° (100° to 180°) while 77 (78.6%) of the patients had active abduction of 160° or more. No decline in abduction was noted among the 29 patients (29.6%) followed up for six years or more. This procedure involving release of the contracted internal rotators of the shoulder combined with decompression and neurolysis of the axillary nerve greatly improves active abduction in young patients with muscle imbalance secondary to obstetric brachial plexus palsy.
We describe 20 patients, aged between 43 and 88 years, with delayed nerve palsy or deepening of an initial palsy caused by arterial injury from low-energy injuries to the shoulder. The onset of palsy ranged from immediately after the injury to four months later. There was progression in all the patients with an initial partial nerve palsy. Pain was severe in 18 patients, in 16 of whom it presented as neurostenalgia and in two as causalgia. Dislocation of the shoulder or fracture of the proximal humerus occurred in 16 patients. There was soft-tissue crushing in two and prolonged unconsciousness from alcoholic intoxication in another two. Decompression of the plexus and repair of the arterial injury brought swift relief from pain in all the patients. Nerve recovery was generally good, but less so in neglected cases. The interval from injury to the repair of the vessels ranged from immediately afterwards to 120 days. Delayed onset of nerve palsy or deepening of a nerve lesion is caused by bleeding and/or impending critical ischaemia and is an overwhelming indication for urgent surgery. There is almost always severe neuropathic pain.
We reviewed 39 patients with displaced three- and four-part fractures of the humerus. In 21 patients (group A) we had used an anatomical prosthesis for the humeral head and in 18 (group B) an implant designed for fractures. When followed up at a mean of 29.3 months after surgery the overall Constant score was 51.9 points; in group A it was 51.5 and in group B 52.4 points. The subjective satisfaction of the patients was assessed using a numerical rating scale and was similar in both groups. In group A complete healing of the tuberosities was found in 29% and 50% in group B. Partial integration was seen in 29% of group A and in only one patient in group B, while resorption was noted in 43% of group A and 44% of group B. The functional outcome was significantly better in patients with complete or partial healing of the tuberosities (p = 0.022). The specific trauma prosthesis did not lead to better healing of the tuberosities. The difference in clinical outcome obtained by the two designs did not reach statistical significance.
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.
Ulnar nerve function, during and after open reduction and internal fixation of fractures of the distal humerus with subperiosteal elevation of the nerve, was assessed by intra-operative neurophysiological monitoring. Intermittent recording of the compound muscle action potentials was taken from the hypothenar muscles in 18 neurologically asymptomatic patients. The mean amplitude of the compound muscle action potential after surgery was 98.1% (