humeral head resurfacing was proposed as a treatment for glenohumeral arthrosis in an attempt to preserve the original anatomy and avoid humeral head resection .
preservation of humeral head maintained the native inclination , offset , head shaft angle , and version of humerus [ 13 ] .
other advantages include a shorter operating time , reduced blood loss , and fewer complications .
another advantage is that , unlike stemmed implant , there is no need for a straight humeral canal to accommodate a long stem .
this allows easier later revision to a conventional total shoulder arthroplasty , if required [ 1 , 2 ] .
it is an attractive option in both the old and the young patients [ 4 , 5 ] .
the disadvantage of resurfacing is the limited exposure to glenoid when wanting to perform a total shoulder resurfacing arthroplasty , but this does not affect when resurfacing the humeral head alone .   the primary aim of our study was to report the results of humeral resurfacing arthroplasty in a consecutive series of patients at a district general hospital practice
twenty - one consecutive patients underwent shoulder resurfacing ( aequalis , tornier , usa ) between october 2007 and november 2009 for symptomatic end - stage glenohumeral arthrosis . clinical examination and radiographic evidence
patient demographics , duration of surgery , intraoperative findings , and complications were prospectively recorded .
of the 21 patients , one patient had worsening of symptoms and underwent revision to a stemmed total shoulder replacement in less than 2 years , one patient died of unrelated cause , and in one patient the humeral head collapsed at the time of impaction of the definitive component and therefore was converted to a stemmed hemiarthroplasty intraoperatively .
therefore 18 patients with a mean followup of 36.3 months ( range 2454 months ) were included in the study .
there were 6 men and 12 women with a mean age of 75.1 years ( range 5891 years , 95% ci of the sd was 70.8 to 79.4 ) , and there were 7 right and 11 left shoulders ( table 1 ) .
the mean duration of preoperative symptoms was 33.6 months ( range 6120 months , 95% ci of the sd was 22.6 to 45.2 ) .
all patients were operated on in the beach chair position under general anaesthesia and an interscalene nerve block .
the shoulder was exposed by a deltopectoral approach with the upper third of subscapularis and the joint capsule reflected in one layer .
the cartilage of humeral head and glenoid were inspected for wear , and osteophytes were excised from the head of the humerus .
the rotator cuff was inspected for its integrity , and either a normal appearance or partial tear was recorded .
any inflammatory pathology of the rotator interval , integrity of the labrum and the long tendon of the biceps brachii and loose bodies in the inferior recess were recorded .
a guide wire was then introduced in the centre of the humeral head which was reamed to the measured size , and trial component inserted after a cruciate keel made a foot anchor in the cancellous bone of the humeral head .
soft tissue releases were undertaken , and stability and range of movement of the shoulder were assessed with trial implant in situ .
subscapularis tendon and joint capsule were repaired using the tendon - to - tendon technique .
the operation was performed by the senior author or by an orthopaedic trainee under direct supervision of the senior author .
the mean duration of anaesthesia that included surgical time was 112 minutes ( range 75150 minutes , median 120 minutes ) .
this included monitoring of postoperative pain and neurovascular status , two further doses of iv cefuroxime 1.5  gm each at 8 and 16 hours , a check x - ray of the shoulder 's anteroposterior and lateral views , a sling to be worn for comfort , no external rotation beyond neutral for 3 weeks and no active external rotation for 6 weeks , physiotherapy advice at discharge , and a physiotherapy followup at 3 weeks postoperatively .
clinical outcome of the operation was assessed by patients ' self - reported oxford shoulder score ( oss ) for pain .
it has a best possible score of 48 and the worst score of 0 [ 6 , 7 ] .
paired two - tailed p value was calculated to assess improvement in the outcome of the procedure , and a value of < 0.05 was considered statistically significant .
oss is a patient - reported outcome measure , and its reliability has been validated against constant shoulder score , sf36 [ 6 , 8 , 9 ] , western ontario rotator cuff index ( worc ) , and shoulder pain and disability index ( spadi ) .
the median duration of hospital stay was one day ( mean 2 days , range 18 days ) .
one patient complained of chest pain postoperatively and stayed for 8 days in the hospital .
she was diagnosed to have a triple vessel coronary disease , which delayed her discharge due to investigative procedures .
she later underwent a coronary artery angioplasty . the pre - operative mean oss of 15 ( range 329 , 95% ci of the sd was 10.6 to 19.4 ) improved by 19.5 points to a final mean oss of 34.5 ( range 647 , 95% ci of the sd was 29.3 to 39.7 ) .
the improvement of oss was highly significant with a two - tailed p value less than 0.0001 and 95% confidence interval of this difference from 14.2 to 24.7 .
15 patients ( 83.3% ) had greater than 11-point improvement of oss ( table 2 ) .
one patient developed adhesive capsulitis and his pre - operative oss of 18 declined to 15 at 54 months followup .
this patient then underwent arthroscopic capsular release ; however , he did not respond to further oss questionnaires .
two patients each had 3 and 4 points improvement of oss ( table 2 ) .
one of them had radiating pain from cervical spondylosis and was referred to pain clinic for management of her symptoms .
no identifiable cause for the lack of greater than 4 points improvement of oss was found in the other patient .
apart from one patient , the remaining 17 patients were very or fairly pleased with the operation and , if they could go back in time , they still would choose to have the same operation .   of the excluded patients
, one had an intraoperative collapse of the humeral head while impaction of the definitive implant and therefore was converted to a stemmed hemiarthroplasty .
one patient had poor initial result from the resurfacing procedure and was revised to total shoulder replacement within the first two years .
he made a significant improvement to a final oss of 30 at one year after total shoulder replacement .  
there were no wound healing problems , infection , deep vein thrombosis , pulmonary embolism , and neurovascular deficits .
over the past twenty years , shoulder resurfacing arthroplasty has gained popularity as an alternative to conventional shoulder arthroplasty for the treatment of glenohumeral arthropathy .
the potential advantages of humeral resurfacing , as compared with conventional shoulder arthroplasty , that include minimal bone resection , a short operative time , low prevalence of humeral periprosthetic fractures , maintenance of head shaft angle , and an ease of revision to a conventional total shoulder replacement , if needed , are well documented [ 1 , 2 , 11 ] .
outcomes of various surface replacement arthroplasty designs have been comparable with those of arthroplasties with a stemmed prosthesis in numerous short and mid - term follow - up studies [ 1 , 2 , 11 ] .
these include the copeland surface replacement prosthesis ( biomet ) , the durom cup ( zimmer ) , total articular replacement arthroplasty prosthesis ( depuy orthopaedics [ warsaw , in , usa ] , and howmedica [ rutherford , nj , usa ] ) [ 1 , 2 , 12 , 13 ] ; however , our study presents results of the aequalis shoulder resurfacing implant ( tornier ) which have not been published in the literature .
our consecutive series of 18 patients with end - stage glenohumeral arthritis showed a mean 19.5 points ( range 3 to 36 ) improvement in oss at a mean followup of 36.3 months .
these results are comparable to change in the oxford shoulder score of a mean 25 points ( range 42 to 17 ) with tess anatomic prosthesis ; however , this study used the older version of oss [ 8 , 9 ] with best possible score of 12 points and worst score of 60 points .  
most patients ( 94.5% ) were very or fairly pleased with the operation similar to the 90% satisfaction rate reported by huguet et al . .
our overall complication rate was 14.3% ; however , this can partly be attributed to the initial learning curve rather that to the design or performance of the implant .
the reasons for failure include poor selection of a patient where the humeral head collapsed intraoperatively at the time of impaction of the definitive prosthesis .
and one patient who developed adhesive capsulitis , unrelated to the surgical procedure , presented with a fall in oss score by three points and underwent arthroscopic capsular release .
our consecutive series of patients shows the good results through historical analysis of the prospectively collected data with no loss to followup .
our study of this implant is from a nonoriginating center of design and production , and to date the results of this implant have not been reported in the literature .
the results show that it is comparable with previously published studies on other resurfacing implants [ 1 , 2 , 14 ] .
the limitations of our study are due to smaller number of patients and early followup .
however , given the available data , our study shows very good results with aequalis shoulder resurfacing prosthesis .
it was not the purpose of this study to compare shoulder resurfacing with stemmed shoulder replacements , and no overall consensus was reached favoring one over the other .
this may need a prospective , randomized , long - term study in the future .
 
 aim . to evaluate results of aequalis humeral head resurfacing in patients with end - stage glenohumeral arthritis at a minimum followup of two years . 
 patients and methods . 
 twenty - one consecutive patients underwent humeral head resurfacing hemiarthroplasty between 2007 and 2009 . 
 three patients did not fulfill the inclusion criteria . 
 18 patients with mean age of 75.1 years ( range 5891 years ) and a mean duration of preoperative symptoms of 33.6 months ( range 6120 months ) were analyzed . 
 patients ' self - reported oxford shoulder score ( oss ) was collected prospectively and was used as an assessment tool to measure final outcome . 
 results . 
 the mean initial oss was 15 ( range 329 ) . 
 the score improved by an average of 19.5 points at a mean followup of 36.3 months ( range 2454 months ) to reach a mean final oss of 34.5 ( range 647 ) . 
 the improvement of oss was highly significant with a two - tailed p value less than 0.0001 . 
 the overall patient satisfaction was 94% . 
 conclusion . 
 this study demonstrates aequalis shoulder resurfacing hemiarthroplasty as a reliable procedure , away from its originating center , for improvement of shoulder function as shown by the patients ' self - reported outcome score ( oss ) in end - stage glenohumeral arthritis at a minimum followup of 2 years . 
1. Introduction
2. Patients and Methods
3. Results
4. Discussion