the indications for our approach were as follows : ( 1 ) isolated pcl avulsion fracture ; and ( 2 ) posterior tibial sag present at 90 of knee flexion .
intra - articular lesions except pcl avulsion fracture were excluded using preoperative magnetic resonance image because of posteromedial approach and the consequential prone position .
a c - arm device was used to avoid the penetration of growth plate by the anchors in pediatric or adolescent patients .
patients were placed in the prone position , with the knee flexed 20 to 30. an oblique incision of < 10 cm was made between semitendinosus tendon and medial head of the gastrocnemius ( fig .
the medial head of the gastrocnemius was held laterally to expose the posterior capsule of the knee joint .
capsulotomy with an l - shaped incision was made longitudinally and then extended laterally to expose the fracture site ( fig .
after debridement of fracture site , 2 suture based anchors ( 3.5 mm ; biomet sports medicine , warsaw , in , usa ) were inserted into the superomedial and superolateral region of the fracture site .
each suture limb from the proximal row was placed through the hole at the end of the push - lock device ( 3.5 mm ; bio - pushlock , arthrex inc . , naples , fl , usa ) .
pilot holes for the push - lock device were created using a punch just inferior to the distal edge of the fracture site .
after the device was fully engaged in the pilot hole , the sutures were cut .
the use of a knotless anchor provides a compressive force and consequently fixes the reduced avulsion fragment strongly to the fracture bed ( fig .
if the patients were children , the anchors were inserted so as not to penetrate a physeal plate .
a well - padded plaster splint was applied to the knee at 5 to 10 of flexion . on the first day , after surgery , the drain was removed and patients were encouraged to start quadriceps muscle strengthening exercise and begin non - weight bearing walking using crutches .
after 2 weeks , protected range of motion exercise was started and partial weight bearing ambulation using crutches was permitted with locked brace in full extension .
six weeks later , the brace was unlocked and the patients began full weight bearing ambulation . at 8 weeks , the brace was removed and patients were encouraged to increase activity gradually . a 20-year - old man presented with a right knee injury resulting from a motor vehicle accident .
clinical examination revealed a swollen knee , limited range of motion and posterior tibial sag at 90 on knee flexion .
the knee range of motion was 135 with a flexion 135 and flexion contracture 0 after 2 weeks postoperatively .
the patient was able to return to his usual daily activities after postoperative 6 months ( fig .
2 ) . a 13-year - old boy presented with left knee injury resulting from a fall . clinical examination revealed hemarthrosis of the knee , limited range of motion , and posterior tibial sag .
the knee range of motion was 140 with flexion 140 and flexion contracture 0 after 4 weeks postoperative .
a well - padded plaster splint was applied to the knee at 5 to 10 of flexion . on the first day , after surgery , the drain was removed and patients were encouraged to start quadriceps muscle strengthening exercise and begin non - weight bearing walking using crutches .
after 2 weeks , protected range of motion exercise was started and partial weight bearing ambulation using crutches was permitted with locked brace in full extension .
six weeks later , the brace was unlocked and the patients began full weight bearing ambulation . at 8 weeks , the brace was removed and patients were encouraged to increase activity gradually .
a 20-year - old man presented with a right knee injury resulting from a motor vehicle accident . clinical examination revealed a swollen knee , limited range of motion and posterior tibial sag at 90 on knee flexion .
the knee range of motion was 135 with a flexion 135 and flexion contracture 0 after 2 weeks postoperatively .
the patient was able to return to his usual daily activities after postoperative 6 months ( fig .
a 13-year - old boy presented with left knee injury resulting from a fall . clinical examination revealed hemarthrosis of the knee , limited range of motion , and posterior tibial sag .
the knee range of motion was 140 with flexion 140 and flexion contracture 0 after 4 weeks postoperative .
currently , open reduction or arthroscopic fixation is more commonly used in treatment of displaced pcl tibial bony avulsion.3456 ) the latter has both advantages and disadvantages . since the site of attachment of the pcl to the tibia is located deep within the posterior tibial plateau , multiple arthroscopic sutures and tunnels are required , making the procedure more challenging and difficult .
furthermore , some authors reported that arthroscopic fixation using suspensory device needs a sizeable drill hole that may break thinner bone fragments.9 ) open reduction can be performed with a traditional s - shaped approach , but this incision is associated with injury to adjacent neurovascular structures . in contrast , we used a less invasive posteromedial approach , which had several advantages , including exposure of the posterior capsule through the gap between the medial head of the gastrocnemius and the semitendinosus muscle . with the approach in this study , it is possible to minimize risks of damage to vessels and nerves , as well as providing satisfactory exposure of the fracture site .
similar methods using posteromedial approach with suture anchors are previously reported.6 ) these studies used 2 suture anchors and fixed bony fragment by knotting with the sutures of 2 suture anchors .
the most important advantage of the present suture bridge fixation technique with posteromedial incision , is its indication for use regardless of the thickness , size , and comminution of bony fragment .
this technique is similar to the double - row , trans - osseous equivalent or suture bridge techniques for rotator cuff repair or internal reduction and fixation of greater tubercle fractures of the humerus .
it allows for a simple reproducible anatomic reduction and compression of the fracture fragment , even though the fragment is small or comminuted .
furthermore , suture anchor is relatively small , as compared to other fixation devices , such as cannulated screws , wires , sutures , and absorbable screws .
the anchor also offers strong purchase , and the attached suture can resist strong tension , resulting in reliable fixation .
previous study on anterior cruciate ligament avulsion fracture , reported that suture bridge construct provides superior fixation with regard to ultimate load , as compared with standard screw fixation and suture fixation in biomechanical analysis of suture bridge fixation for tibial eminence fractures.10 ) similarly , the suture bridge mattress fixation in this study may provide enough ultimate load and compressive force to the avulsed fragment and thus maximize the surface area for bony healing . furthermore , there is no risk of causing comminution . in conclusion
, the results of the study indicated that the posteromedial approach , combined with suture anchors , is a suitable treatment for isolated tibial avulsion fractures of the pcl .
 we presented a surgical technique including a suture bridge technique with relatively small incision for the reduction and fixation of posterior ligament avulsion fractures . 
 a suture anchor was used to hold the avulsed fragment and a knotless anchor was used to continuously compress the bony fragment into the fracture site , thereby maintaining reduction during healing . 
TECHNIQUE
Postoperative Rehabilitation
Case 1
Case 2
DISCUSSION