there is a lack of agreement of the optimal treatment for the acute achilles tendon rupture ( aatr ) . reports in the literature are equivocal or even contradictory . currently , there are four different types of interventions , including two types of surgical repair , ( 1 ) open , or ( 2 ) minimally invasive procedures ; and two types of nonoperative , conservative management , ( 3 ) simple immobilisation , or ( 4 ) functional bracing . surgical repair runs the risk of complications , such as wound dehiscence and infection , sural nerve injury , or scar and tissue adhesions . nonsurgical management runs the risk of tendon re - rupture and poor functional outcome , and is regarded as alternative more suited to older patients . minimally invasive procedures should reduce the risk of surgical complications , but retain other benefits of surgical treatment , particularly functional improvements with less time away from work and sports [ 13 ] . this study aimed to compare the efficacy of open surgery with a minimally invasive procedure performed with achillon device ( integra , newdeal ) . patients were included in the study when they appeared in our institution within seven  days of an aatr with a positive clinical diagnosis on the thompson squeeze test , exhibited a palpable gap , showed loss of plantar flexion strength , were over 18  years old and provided written agreement to participate in the study . patients were excluded when they had chronic ( neglected ) tears , concomitant injuries , open tears , avulsion from the calcaneus , or systemic diseases such as rheumatoid arthritis , diabetes , or any disease such as required medications that might impair tendon healing ( e.g. , corticosteroids , fluorochinolones ) . patients with general surgical contraindications were also excluded from the study . after gaining approval from the institutional ethical committee , we invited 57 consecutive patients that fulfilled the inclusion criteria to participate in the study ; six ( 10  % ) patients refused and were treated according to the surgeon s preference ; 51 patients provided written consent and were included in the study . we implemented a simple randomisation protocol , where patients were asked to choose one of two opaque envelopes that contained a paper indicating the type of surgery . group i ( n  =  24 patients ) was treated with the minimally invasive procedure with the achillon device and group ii ( n  =  27 patients ) were treated with traditional open surgery with krackow - type sutures . a total of 22 patients from group 1 and 25 patients from group ii were available at the last follow - up . the mean age in group i was 44.8  years ( from 30 to 62  years , sd 9.2 ) and in group ii , 47.1  years ( from 26 to 74  years , sd 13.3 ) . the aatr had occurred during sports activities in 35 patients ( 75  % ) , during work in seven patients ( 15  % ) , and in home accidents in five patients ( 10  % ) . only two females participated in the study , and one was enrolled to each treatment group . all patients were treated on the first day after admission and discharged home the following day . all procedures were performed under spinal anaesthesia with a tightly applied tourniquet ( 300  mmhg ) . as a routine each patient was treated with monofilament , absorbable polydioxanone ( pds , ethicon ) or polyglyconate ( maxon , covidien ) sutures . immediately after surgery , patients were placed in a below - the - knee cast that provided approximately 20 plantar flexion for six  weeks . all patients were asked to walk on crutches without bearing weight on the affected ankle . low molecular - weight heparin injections were given during the cast immobilisation period to prevent deep vein thrombosis and pulmonary embolism . after six  weeks , the cast was removed , and full weight bearing was allowed . two orthopaedic residents , not involved in the treatment process , performed the last follow - up assessment . primary outcome measures were the number of important surgical complications , including infections , achilles tendon re - ruptures , and sural nerve lesions . secondary outcomes were pain , assessed by the visual analog scale ( vas ) , time to return to work , ability to return to sports or pre - rupture activity levels , calf circumference , strength of calf muscles ( measured by a single heel - rise test ) , range of ankle movements , and the length and appearance of the surgical scar . patients were asked to assess scar cosmesis subjectively as very good , good , acceptable , or unacceptable . the critical level of significance was p  =  0.05 . for parameters with normal distributions and homogeneous variances , the student s t - test was used to evaluate significant differences in mean values . the homogeneity of variance was determined with levene s test . for parameters with non - uniform variations , we applied the cochran  cox test . for parameters with non - normal distributions , the nonparametric mann the critical level of significance was p  =  0.05 . for parameters with normal distributions and homogeneous variances , the student s t - test was used to evaluate significant differences in mean values . the homogeneity of variance was determined with levene s test . for parameters with non - uniform variations , we applied the cochran  cox test . for parameters with non - normal distributions , the nonparametric mann there were no achilles tendon re - ruptures or sural nerve lesions observed in either group . one patient from group ii required readmission for surgical debridement and removal of a portion of tendon that was necrotic and infected . he reported persistent pain , with a vas assessment of grade 7 , and he was a candidate for further surgery . the two other cases of infected , delayed wound healing resolved with oral antibiotic and local treatments . the average vas in groups i and ii were 1.6 and 1.7 , respectively ( p  >  0.05 ) . values of measured clinical parameters after treatment for aatr are presented in table  1 . the only statistically important difference between groups was the scar length ( p  <  0.05 ) . two patients in group ii developed keloid formations , but both considered the outcome as acceptable . out of the 35 patients that sustained the aatr during a sporting activity , only 16 ( 46  % ; nine in group i and seven in group ii ) returned to their previous activity level ; seven ( 20  % ) stated that they were unable to perform their sporting activity at the previous level , and 12 ( 34  % ) changed sports disciplines . out of 19 patients that discontinued their sport , nine ( 47  % ) belonged to group i , and ten ( 53  % ) to group ii . all patients returned to their previous work , except the one that required a re - operation due to a septic complication ; that patient remained on sick leave.table 1measured clinical parameters between group i and group ii after treatment for acute achilles tendon rupturegroup i : minimally invasive procedure average value ( sd)group ii : open surgery average value ( sd)p valueankle dorsiflexion  treated limb ( degrees)14.2 ( 5.1)12.6 ( 4.2)0.40ankle plantar flexion  treated limb ( degrees)39.6 ( 8.1)41.6 ( 10.8)0.50calf circumference  treated limb ( centimeters)36.4 ( 3.3)37.4 ( 4.8)0.53single heel - rise test ( number of repetitions on the affected limb)15.2 ( 6.3)16.9 ( 6.2)0.33scar length ( centimeters)4.0 ( 0.9)14.5 ( 3.3)0.005time to return to work ( weeks)4.8 ( 2.2)5.5 ( 2.7)0.71 measured clinical parameters between group i and group ii after treatment for acute achilles tendon rupture the achilles tendon is the most commonly injured tendon in recreational athletes , and the incidence is rising due to increasing numbers of people attempting to remain active and maintain fitness [ 1 , 4 ] . regardless of the treatment method , some functional deficits may persist for more than ten  years after an aatr [ 5 , 6 ] . four recently published meta - analyses of randomised control trials suggested that open surgical treatment of aatr can reduce the risk of re - ruptures compared to nonoperative treatments ; however , open surgery runs significant risk of surgical complications , including surgical site infections , nerve injuries , and skin adhesions [ 13 , 7 ] . aatr can heal in continuity , resulting in a lengthened tendon , with decreased push off , muscle weakness , gait abnormalities and need for repeated surgery and shortening . some authors reported that percutaneous and minimally invasive techniques could limit the number of surgical complications [ 911 ] . several different minimally invasive surgical techniques and special devices have been introduced to perform percutaneous or minimally invasive repairs [ 1217 ] . data from meta - analyses have supported minimally invasive surgery , because it decreased the risk of superficial wound infection and provided high patient satisfaction . however , no statistically significant difference was found between minimally invasive and open surgery for achilles tendon repairs with respect to the incidence of the most disastrous complications ; i.e. , re - rupture and deep infection rates . in a prospective study , guillo et al . reported excellent results with a minimally invasive technique in terms of muscle strength and return to activity at pre - injury or better levels ( more than 90  % ) , but they did not have a control group for comparison . compared open and percutaneous procedures , and found that both methods afforded similar restoration of clinical , ultrasound , and isokinetic patterns . on the other hand , in a series of 124 cases , maes et al . applied percutaneous repairs with the tenolig device , and they reported a 10  % re - rupture rate and a 6.5  % sural nerve injury rate . taglialavoro et al . confirmed a high complication rate ( 33  % ) with the tenolig device . in 2002 , assal et al . they reported excellent mid - term results , and no problems were reported with wound healing , infections , or sensory disturbances in sural nerves . an in vitro biomechanical cadaveric study demonstrated that the achillon device offered stronger repair than the classic krackow procedure . longo et al . also confirmed excellent biomechanical performance and stability with an achillon  like suture configuration . garrido et al . and feldbrin et al . reported highly satisfactory clinical results with the achillon device [ 10 , 23 ] . in the present study , the achillon suture guide provided excellent results ; it facilitated tendon healing and avoided surgical complications . however , for patient and doctor , the most important outcomes , the re - rupture and infection rates , were not significantly different from those observed after open surgery . one of the most important secondary outcome measures was the standing heel - rise test . this simple , readily available test can be performed in every physician s office , and it offers clinicians a reliable assessment of calf - muscle performance . the heel - rise appears to be an important early achievement in the achilles tendon healing process ; it reflects the general level of healing , and it influences patient - reported outcome and subsequent physical activity [ 24 , 25 ] . in our study , the average number of heel - rise repetitions was similar in both groups , but below the 25 repetitions recommended by lundsford for displaying normal function . all but one patient in the series returned to their previous job , but only 46  % regained their previous sporting activity level . post - treatment sport activity measurements incorporated both function and physical activity as a secondary outcome . in other studies that assessed minimally invasive achilles tendon surgery , a majority of patients returned to the pre - injury activity level [ 10 , 23 ] . for example , guillo et al . and talbot et al . reported that 80  % and 74  % of patients , respectively , had returned to pre - operative activity levels [ 17 , 26 ] . in our study , the radical decline observed in post - treatment sporting activities , in the authors opinion , was due to the long period of non - weight bearing and cast immobilisation . both treated groups received similar , traditional postoperative treatment regimens established at our institution . after an average of ten  years follow - up , horstmann et al . found significant functional deficits in muscle strength , endurance , and muscle activity , measured with dynamometry and electromyography in patients treated surgically , followed by six  weeks of immobilisation in a cast . in recent studies , early range of motion and immediate weight bearing activities were strongly recommended for both surgical and nonoperative treatments [ 3 , 10 , 24 , 26 , 27 ] . a randomised , control trial performed by twaddle et al . supported early motion ; in patients that received either surgical or nonsurgical treatment , they observed comparable functional results and a low recurrent rupture rate . that suggested that early motion was one of the most the important factors in recovery after aatr . we believe that a radical decline in sporting activity levels reflected functional deficits created by immobilisation , non - weight bearing and lack of rehabilitation protocols . changes in post - treatment protocol are necessary to improve the functional results . the excellent biomechanical results with the achillon suture system provided motivation for further study with immediate weight bearing and early , controlled movement regimens . a limitation of our study was that we did not use a blinding method to avoid a detection bias . another drawback was that our results represented treatments by two surgeons that treated patients similarly , but not identically ; for example , there could be differences in the method of inserting the achillon jig , operation times , tissue handling , tissue layer closure procedures , etc . . minimally invasive aatr surgery performed with the achillon device limited the incidence of the most severe surgical complications , such as infection and tendon re - rupture ; however , the results were not significantly different from those using traditional open surgery .
purposesurgical treatment of an acute achilles tendon rupture can effectively reduce the risk of re - rupture , but it increases the probability of surgical complications . 
 we postulated that a minimally invasive surgical treatment might reduce the number of complications related to open surgery and improve the functional results.methodwe enrolled 47 patients with acute achilles tendon ruptures in a prospective , randomised trial to compare clinical results and complications between a minimally invasive procedure with the achillon device and traditional open surgery with krackow - type sutures . 
 the average patient age was 46  years . 
 the follow up time was 24  months.resultsno achilles tendon re - rupture or nerve injury occurred in treated patients . 
 there were two cases of wound infections in the open surgery group , and one superficial wound infection occurred in the minimally invasive group . 
 the groups were not significantly different in the amount of pain , range of ankle movements , the single heel - rise test , calf circumference , or time to return to work and sports.conclusionafter a two  year follow - up period , we found no significant differences in clinical outcomes between groups treated with traditional open surgery or minimally invasive surgery .