partial - thickness rotator cuff tears ( ptrcts ) have the potential to cause significant pain and disability in affected patients .
after failed conservative management , operative intervention is typically indicated for patients with persistent symptoms .
surgical treatment is generally limited to tear debridement with or without acromioplasty or tear repair with or without acromioplasty .
most authors recommend repair of tears involving 50% or more of the tendon thickness . with the advent of magnetic resonance imaging ( mri ) and shoulder arthroscopy , more
unfortunately , high - quality data on the management of ptrcts are relatively lacking in the literature when compared with those available on full - thickness tears .
partial - thickness rotator cuff tears are classified into three subtypes : bursal side , articular side , and intratendinous tears . among them , intratendinous tears are an important clinical entity .
intratendinous tears are characterized by the absence of fiber disruption on both the bursal and articular surface of the rotator cuff .
a cadaveric study reported that this type of tear was the most frequent ( 55% ) among all of the partial - thickness tears .
because the intratendinous tear has no communication to the subacromial space and the glenohumeral joint , it is probably the most difficult condition to be diagnosed among the three types of the partial tear .
. however , confirmation of such lesions during operation can be difficult . only a few literature described how to find the intratendinous tears during surgery .
both bursal side and articular side rotator cuff tears have been extensively studied , but little has been written about intratendinous tears . although arthroscopy has led to an increase in treatment of ptrcts , there were only few case reports concerning about arthroscopic repair of intratendinous tears .
in addition , no one reported the structural outcomes after arthroscopic repair of intratendinous tears .
the purpose of this study was to evaluate the functional results and structural outcomes after arthroscopic repair of intratendinous ptrcts .
our hypothesis was that arthroscopic repair of intratendinous ptrcts could achieve good clinical and structural results .
this study received approval from the investigational review board . from february 2008 to april 2012 , 36 consecutive patients ( 36 shoulders ) with intratendinous tears underwent arthroscopic treatment .
the inclusion criteria in this study were ( 1 ) symptoms lasting more than 3 months with proper conservative treatment and ( 2 ) no major associated pathology that would need to be addressed at the time of arthroscopic surgery , such as a frozen shoulder or bankart lesion .
three patients with frozen shoulder were excluded from this study . therefore , 33 patients met the inclusion criteria and were retrospectively studied .
all of the 33 patients ( 33 shoulders ) were available for evaluation of clinical follow - up .
the mean age at the time of surgery was 42.9  9.9 years ( range , 2261 years ) .
a total of 18 ( 54.5% ) patients had repair of the dominant shoulder , with 15 left and 18 right shoulders involved .
the active range of motion ( rom ) was 155 ( range , 60180 ) in flexion , 156 ( range , 45180 ) in abduction , 43 ( range , 1555 ) in external rotation , and active internal rotation was l3 ( range , t7gluteus ) .
preoperatively , all of the patients received bilateral radiographs of anteroposterior and supraspinatus outlet views and a noncontrast mri examination .
oblique sagittal , oblique coronal and transverse , t2-weighted fat - depressed , fast spin echo images were acquired for all shoulders
. the diagnostic signs of intratendinous tears included a defect within the rotator cuff and fluid - intensity signals within the tendons , which did not connect to the surface of the tendon .
depending on the serial oblique coronal images , we could estimate the distance between the center of the tear and the long head of the biceps tendon ( bt ) ( slice thickness was 4 mm ) .
this enabled us to identify the tear in the operation more easily . before operation ,
conservative therapy comprised rest , modification of activities , local application of heat or cold , nonsteroidal anti - inflammatory medication , subacromial steroid injection , gentle exercises for maintaining and increasing rom , and muscle - strengthening exercises .
all of the arthroscopic procedures were performed with the patient under general anesthesia in the beach - chair position .
diagnostic arthroscopy was performed , and intra - articular pathology was treated in the appropriate manner .
the tear was then localized preliminarily under arthroscopic visualization . according to the distance between the long head of the bt and the tear , which was estimated on preoperative mri
, we percutaneously penetrated the cuff with a spinal needle near tendon insertion to the humeral head . to determine this distance as accurately as possible
( errors can be made as a result of the magnifying effect of the arthroscope ) , the width of the long head of the bt ( approximately 6 mm ) was taken as a guide . a no
. 1 polydioxynone ( pds ) suture ( ethicon , somerville , nj , usa ) was introduced through the spinal needle , and the needle was then removed [ figure 1 ] .
arthroscopic view from a posterior glenohumeral portal of a right shoulder shows introduction of a polydioxynone marking suture through supraspinatus tendon .
hh : humeral head ; bt : biceps tendon ( note : all arthroscopic views are of right shoulders oriented in the beach - chair position ) .
when looking through the posterolateral portal , marking suture could be found in the subacromial space .
careful evaluation of the cuff insertion was then performed around the pds suture [ figure 2 ] .
the bursal surface was intact in all of the patients , but some areas of the tendon insertion appeared soft and lax as the tendon was palpated using a hooked probe [ figure 3 ] . after inserting the probe into the center of the suspected lesion within the midsubstance of the tendon , a cavity within the tendon could be felt and the probe could easily touch the bone trough on the greater tuberosity [ figure 4 ] .
arthroscopic view from a posterolateral subacromial portal shows inspection of the intact bursal side tendon with hooked probe around the polydioxynone suture .
arthroscopic view from a posterolateral subacromial portal shows that the bursal side tendon appeared soft and lax . after inserting the probe into the tendon
, a cavity within the tendon could be felt , and the bone trough of the greater tuberosity could be palpated easily .
arthroscopic view from a posterolateral subacromial portal . after confirming the intratendinous tear , the bursal side tendon was incised .
all the degenerative tissues of the tendon were removed until normal articular side tendon fibers were identified as being inserted into the greater tuberosity [ figure 5 ] .
a cancellous bed was prepared at the site of the repair by removal of a thin layer of cortical bone with a power burr to promote healing of the reattached cuff .
standard single - row repair was performed with one or two suture anchors according to tear length [ figure 6 ] .
arthroscopic view from a posterolateral subacromial portal shows the intratendinous tear with the intact articular side tendon . *
the arm was maintained in a sling at 15 of abduction and neutral rotation for 6 weeks .
six weeks later , active rom exercises that progressively applied loads to the repair construct were allowed .
strengthening exercises that focused on restoring power and endurance to the healed rotator cuff muscles began after 3 months and were continued until 46 months postoperatively .
the university of california at los angeles ( ucla ) shoulder score and the constant score were used before the operation and at the final evaluation .
tendon healing was classified into five types according to sugaya 's criteria as follows : type i , sufficient thickness compared with a normal cuff with homogenously low intensity on each image ; type ii , sufficient thickness compared with a partial high - intensity area ; type iii , insufficient thickness with less than half the thickness without discontinuity , suggesting a partial - thickness , delaminated tear ; type iv , presence of a minor discontinuity in only one or two slices on both oblique coronal and sagittal images , suggesting a small , full - thickness tear ; and type v , presence of a major discontinuity observed in more than two slices on both oblique coronal and sagittal images , suggesting a medium or large , full - thickness tear .
preoperative and postoperative clinical scores were compared using the paired student 's t - test .
postoperative clinical scores between patients with intact cuff and patients with retears were compared using an independent t - test .
from february 2008 to april 2012 , 36 consecutive patients ( 36 shoulders ) with intratendinous tears underwent arthroscopic treatment .
the inclusion criteria in this study were ( 1 ) symptoms lasting more than 3 months with proper conservative treatment and ( 2 ) no major associated pathology that would need to be addressed at the time of arthroscopic surgery , such as a frozen shoulder or bankart lesion .
all of the 33 patients ( 33 shoulders ) were available for evaluation of clinical follow - up .
the mean age at the time of surgery was 42.9  9.9 years ( range , 2261 years ) .
a total of 18 ( 54.5% ) patients had repair of the dominant shoulder , with 15 left and 18 right shoulders involved .
the active range of motion ( rom ) was 155 ( range , 60180 ) in flexion , 156 ( range , 45180 ) in abduction , 43 ( range , 1555 ) in external rotation , and active internal rotation was l3 ( range , t7gluteus ) .
preoperatively , all of the patients received bilateral radiographs of anteroposterior and supraspinatus outlet views and a noncontrast mri examination .
oblique sagittal , oblique coronal and transverse , t2-weighted fat - depressed , fast spin echo images were acquired for all shoulders .
the diagnostic signs of intratendinous tears included a defect within the rotator cuff and fluid - intensity signals within the tendons , which did not connect to the surface of the tendon .
depending on the serial oblique coronal images , we could estimate the distance between the center of the tear and the long head of the biceps tendon ( bt ) ( slice thickness was 4 mm ) .
before operation , all of the patients received conservative treatment for at least 3 months .
conservative therapy comprised rest , modification of activities , local application of heat or cold , nonsteroidal anti - inflammatory medication , subacromial steroid injection , gentle exercises for maintaining and increasing rom , and muscle - strengthening exercises .
all of the arthroscopic procedures were performed with the patient under general anesthesia in the beach - chair position .
diagnostic arthroscopy was performed , and intra - articular pathology was treated in the appropriate manner .
the tear was then localized preliminarily under arthroscopic visualization . according to the distance between the long head of the bt and the tear , which was estimated on preoperative mri
, we percutaneously penetrated the cuff with a spinal needle near tendon insertion to the humeral head . to determine this distance as accurately as possible
( errors can be made as a result of the magnifying effect of the arthroscope ) , the width of the long head of the bt ( approximately 6 mm ) was taken as a guide . a no .
1 polydioxynone ( pds ) suture ( ethicon , somerville , nj , usa ) was introduced through the spinal needle , and the needle was then removed [ figure 1 ] .
arthroscopic view from a posterior glenohumeral portal of a right shoulder shows introduction of a polydioxynone marking suture through supraspinatus tendon .
hh : humeral head ; bt : biceps tendon ( note : all arthroscopic views are of right shoulders oriented in the beach - chair position ) .
when looking through the posterolateral portal , marking suture could be found in the subacromial space .
careful evaluation of the cuff insertion was then performed around the pds suture [ figure 2 ] .
the bursal surface was intact in all of the patients , but some areas of the tendon insertion appeared soft and lax as the tendon was palpated using a hooked probe [ figure 3 ] . after inserting the probe into the center of the suspected lesion within the midsubstance of the tendon , a cavity within the tendon could be felt and the probe could easily touch the bone trough on the greater tuberosity [ figure 4 ] .
arthroscopic view from a posterolateral subacromial portal shows inspection of the intact bursal side tendon with hooked probe around the polydioxynone suture .
arthroscopic view from a posterolateral subacromial portal shows that the bursal side tendon appeared soft and lax . after inserting the probe into the tendon
, a cavity within the tendon could be felt , and the bone trough of the greater tuberosity could be palpated easily . arthroscopic view from a posterolateral subacromial portal . after confirming the intratendinous tear , the bursal side tendon was incised .
all the degenerative tissues of the tendon were removed until normal articular side tendon fibers were identified as being inserted into the greater tuberosity [ figure 5 ] .
a cancellous bed was prepared at the site of the repair by removal of a thin layer of cortical bone with a power burr to promote healing of the reattached cuff .
standard single - row repair was performed with one or two suture anchors according to tear length [ figure 6 ] .
arthroscopic view from a posterolateral subacromial portal shows the intratendinous tear with the intact articular side tendon . *
the arm was maintained in a sling at 15 of abduction and neutral rotation for 6 weeks .
six weeks later , active rom exercises that progressively applied loads to the repair construct were allowed .
strengthening exercises that focused on restoring power and endurance to the healed rotator cuff muscles began after 3 months and were continued until 46 months postoperatively .
the university of california at los angeles ( ucla ) shoulder score and the constant score were used before the operation and at the final evaluation .
tendon healing was classified into five types according to sugaya 's criteria as follows : type i , sufficient thickness compared with a normal cuff with homogenously low intensity on each image ; type ii , sufficient thickness compared with a partial high - intensity area ; type iii , insufficient thickness with less than half the thickness without discontinuity , suggesting a partial - thickness , delaminated tear ; type iv , presence of a minor discontinuity in only one or two slices on both oblique coronal and sagittal images , suggesting a small , full - thickness tear ; and type v , presence of a major discontinuity observed in more than two slices on both oblique coronal and sagittal images , suggesting a medium or large , full - thickness tear .
preoperative and postoperative clinical scores were compared using the paired student 's t - test .
postoperative clinical scores between patients with intact cuff and patients with retears were compared using an independent t - test .
preoperative plain radiographs showed type ii acromion in 26 patients and type iii acromion in seven patients . on oblique , coronal
t2-weighted fat - depressed images from 33 preoperative mris , 26 patients showed an area of high - signal intensity within the insertion of the supraspinatus tendon , supporting the diagnosis of intratendinous tears [ figure 7 ] .
two patients showed a tendon defect , three showed high signal on the bursal surface of the tendon , and two showed tendon degeneration .
these were interpreted as two full - thickness tears , three bursal side partial tears , and two normal tendons preoperatively .
the intratendinous tears , which were confirmed under the arthroscopy , were found within the supraspinatus tendon in all of the patients .
the coracoacromial ligament surface was fibrillated or rough in all of the patients , indicating the presence of subacromial impingement .
some intra - articular lesions were defined and treated , including two repairs and one debridement of superior labrum anterior and posterior lesion , one debridement of partial rupture of the long head of the bt , one debridement for partial tear of the subscapularis tendon , and three debridements of labrum lesions .
seventeen patients had no pain , 13 patients felt light pain or discomfort occasionally while three patients felt pain during strenuous exercise .
the active rom was 178 ( range , 160180 ) in flexion , 176 ( range , 150180 ) in abduction , 46 ( range , 4050 ) in external rotation , and active internal rotation was t12 ( range t7l3 ) .
both scoring systems reflected significant improvement in the status of the shoulder when the preoperative scores were compared with those at the time of the final follow - up [ table 1 ] .
the mean postoperative ucla score and constant score were significantly higher compared with that preoperatively ( p < 0.001 ) . no significant difference in either postoperative score was found between patients with an intact cuff and those with a cuff retear ( ucla : p = 0.696 , constant : p = 0.834 ) [ table 2 ] .
preoperative and postoperative clinical scores ( n = 33 ) ucla : university of california at los angeles .
comparison of functional outcomes between patients with an intact rotator cuff and those with a retear ucla : university of california at los angeles .
a total of 27 ( 81.8% ) patients received postoperative mri , which was performed at a mean of 15.2 months after surgery ( 645 months ) . there were four type i [ 14.8% , figure 8a ] , 18 type ii [ 66.7% , figure 8b ] , and five type iii retears [ 18.5% , figure 8c ] . in this study
overall , there were 22 intact repaired cuff tendons ( sugaya 's type i or ii ) and five partial tears ( sugaya 's type iii ) .
( a ) type i , sufficient thickness with homogenously low intensity ( white arrow ) ; ( b ) type ii , sufficient thickness with partial high intensity ( white arrow ) ; ( c ) type iii , insufficient thickness without discontinuity ( white arrow ) .
preoperative plain radiographs showed type ii acromion in 26 patients and type iii acromion in seven patients . on oblique , coronal
t2-weighted fat - depressed images from 33 preoperative mris , 26 patients showed an area of high - signal intensity within the insertion of the supraspinatus tendon , supporting the diagnosis of intratendinous tears [ figure 7 ] .
two patients showed a tendon defect , three showed high signal on the bursal surface of the tendon , and two showed tendon degeneration .
these were interpreted as two full - thickness tears , three bursal side partial tears , and two normal tendons preoperatively .
the intratendinous tears , which were confirmed under the arthroscopy , were found within the supraspinatus tendon in all of the patients .
the coracoacromial ligament surface was fibrillated or rough in all of the patients , indicating the presence of subacromial impingement .
some intra - articular lesions were defined and treated , including two repairs and one debridement of superior labrum anterior and posterior lesion , one debridement of partial rupture of the long head of the bt , one debridement for partial tear of the subscapularis tendon , and three debridements of labrum lesions .
seventeen patients had no pain , 13 patients felt light pain or discomfort occasionally while three patients felt pain during strenuous exercise .
the active rom was 178 ( range , 160180 ) in flexion , 176 ( range , 150180 ) in abduction , 46 ( range , 4050 ) in external rotation , and active internal rotation was t12 ( range t7l3 ) .
both scoring systems reflected significant improvement in the status of the shoulder when the preoperative scores were compared with those at the time of the final follow - up [ table 1 ] .
the mean postoperative ucla score and constant score were significantly higher compared with that preoperatively ( p < 0.001 ) . no significant difference in either postoperative score was found between patients with an intact cuff and those with a cuff retear ( ucla : p = 0.696 , constant : p = 0.834 ) [ table 2 ] .
preoperative and postoperative clinical scores ( n = 33 ) ucla : university of california at los angeles .
comparison of functional outcomes between patients with an intact rotator cuff and those with a retear ucla : university of california at los angeles .
a total of 27 ( 81.8% ) patients received postoperative mri , which was performed at a mean of 15.2 months after surgery ( 645 months ) . there were four type i [ 14.8% , figure 8a ] , 18 type ii [ 66.7% , figure 8b ] , and five type iii retears [ 18.5% , figure 8c ] . in this study
overall , there were 22 intact repaired cuff tendons ( sugaya 's type i or ii ) and five partial tears ( sugaya 's type iii ) .
( a ) type i , sufficient thickness with homogenously low intensity ( white arrow ) ; ( b ) type ii , sufficient thickness with partial high intensity ( white arrow ) ; ( c ) type iii , insufficient thickness without discontinuity ( white arrow ) .
to the best of our knowledge , this is the largest study to examine the clinical and anatomical results of intratendinous ptrcts after arthroscopic repair . the combination of decompression and repair with preservation of as much of the intact articular tendon fiber as possible yields a satisfactory clinical outcome .
postoperative mri also showed a high rate of healing of the repaired tendon among our patients .
partial - thickness rotator cuff tear is more difficult to diagnose than a full - thickness tear .
in particular , preoperative diagnosis of intratendinous tears may be the most challenging among the three subtypes of ptrcts .
however , in recent years , advancement in mri , specifically sequence alteration and differential arm positioning , have greatly improved its accuracy in identifying intratendinous tears .
one is a linear high signal within the tendon , which is parallel to the direction of tendon fibers .
the other is a focal defect at the tendon insertion , which has no communication with either surface of the tendon . in the current study , 26 of 33 ( 78.8% )
patients had been diagnosed with intratendinous tears by preoperative mri , showing that mri is an effective way of diagnosing intratendinous tears .
although preoperative diagnosis has become more accurate , intraoperative localization of the tears remains problematic .
this difficulty is due to the absence of overt tendon disruption on both the bursal and articular surfaces of the cuff . in uchiyama
's study , a definitive diagnosis was established by a longitudinal split of the supraspinatus tendon in the area of softening , fraying , edema , erosion , and redness .
itoi and tabata reported three cases where intratendinous tear was suspected when the cuff was soft , fluffy , and bulged when the arm was elevated .
bubble sign  as facilitating the diagnosis of intratendinous tears . in our study , with the help of the marking suture , the inspected area could be minimized , and the tears could be found quickly .
the intratendinous tear was excised in 15 patients , including the whole lesion and a small portion of the greater tuberosity .
the tendon defect was then closed by side - to - side sutures and transosseous sutures .
itoi and tabata reported three cases in which a full - thickness cuff involving the tear was resected and repaired .
few studies have investigated the effectiveness of acromioplasty alone for the treatment of intratendinous tears .
fukuda et al . showed in their histological study that partial - thickness tears have essentially no ability to heal themselves over time .
intratendinous tears biopsied at the time of operative intervention show granulation tissue with rounded , avascular tissue margins without evidence of healing .
biomechanical studies have shown that in the presence of a partial - thickness tear , the strain patterns within the remaining intact rotator cuff change , potentially predisposing the tissue to tear propagation .
according to the results of these studies , tendon repair with acromioplasty may be more suitable . in the current study
, intratendinous tears were converted to bursal side tears after the normal bursal side tendon was incised .
some authors have proposed to complete a full thickness tear and repair it , whereas others believe that the normal articular sided tissue should be reserved because it can protect the repaired bursal side tendon and offer a good opportunity for healing of the repaired tendon .
in addition , with preservation of an intact articular side tendon , some authors tend to perform a full - layer repair whereas others prefer to repair the outer layer only . in the present study ,
we preserved the healthy articular side tendon as much as possible and repaired the bursal flap back to the bone .
good clinical and structural results showed that our technique was effective for intratendinous tears . to the best of our knowledge
, few studies have examined structural outcomes after arthroscopic repair of intratendinous ptrct . in uchiyama
low signal in tendon was found in 7 patients . with regard to our repair technique ,
koh et al . reported good structural integrity ( 88% healing rate ) on mri after arthroscopic full - layer repair .
kim et al . described satisfactory structural integrity ( 89% ) after either conversion to a full - thickness tear repair or only repairing the detached layer . in this study , 22 ( 81.5% ) repaired tendons were intact .
the healing rate is consistent with these studies . whether the tendon integrity affect the clinical result is under debate .
some authors believed that retearing had no effect on the clinical results , especially in small tears .
our results are consistent with these reports . however , further studies are needed to clarify the reason of this interesting finding .
first , this was a retrospective study with a relatively small number of patients and a relatively short time of follow - up .
therefore , this study does not provide a clear understanding of the requirement for treatment of intratendinous rotator cuff tears .
second , because we did not perform subacromial decompression alone to the intratendinous tears , we could not compare both results .
third , postoperative mri scans were taken at 6 months to 4 years ( i.e. , the postoperative period varied ) .
therefore , the structural integrity that we achieved might not match the clinical outcomes at the final follow - up .
 background : partial - thickness rotator cuff tears ( ptrcts ) are being diagnosed more often because of high - resolution magnetic resonance imaging ( mri ) . compared with articular and bursal side tears 
 , there have been few studies about evaluating the clinical and structural outcomes after intratendinous tear repair.methods:from 2008 to 2012 , 33 consecutive patients with intratendinous ptrcts underwent arthroscopic repair . 
 all of them were retrospectively evaluated . 
 the university of california at los angeles ( ucla ) and constant scores were evaluated before operation and at the final follow - up . 
 postoperative cuff integrity was determined using mri according to sugaya 's classification.results:at the 2-year follow - up , the average ucla score increased from 16.7  1.9 to 32.5  3.5 , and the constant score increased from 66.2  10.5 to 92.4  6.9 ( p < 0.001 ) . 
 twenty seven patients received follow - up mri examinations at an average of 15.2 months after surgery . 
 of these 27 patients , 22 ( 81.5% ) had a healed tendon , and five patients had partial tears . 
 there was no association between functional and anatomic results.conclusions:for intratendinous ptrct , clinical outcomes and tendon healing showed good results at a minimum 2-year after arthroscopic repair . 
I
M
Patient selection
Preoperative clinical features
Preoperative images
Conservative treatment
Surgical technique
Rehabilitation
Clinical and magnetic resonance imaging evaluations
Statistical analysis
R
Preoperative imaging findings
Intraoperative findings
Clinical outcomes
Magnetic resonance imaging outcomes
D