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 .