Tibial Spine/Anterior Cruciate Ligament Avulsion Fractures Overview Technique Suture
Itai Gans
Theodore J. Ganley
TREATMENT
It is important to review and know the Meyers and McKeever classification system for tibial spine fractures, as treatment depends on the fracture pattern observed.
Type I fractures are best managed using immobilization techniques in either a long leg cast or fracture brace. The amount of flexion recommended in the literature varies and ranges from 0 to 40 degrees.1,2,3,4,5,6,7 Although few proponents argue for immobilization in hyperextension,8 it generally is not recommended due to patient discomfort2 and the danger of putting posterior structures such as the popliteal artery under tension, potentially causing the development of compartment syndrome.9 The decision to evacuate the hematoma is based on physician’s preference. Rapid healing occurs in skeletally immature patients; as such, most physicians treat type I fractures with 4 to 6 weeks of immobilization.6,7,9,10,11,12 In older children, adolescents, and adults, prolonged periods of immobilization may lead to development of significant knee stiffness and muscle atrophy,13 and the shortest period of immobilization possible that will still maintain reduction is recommended,14,15,16 usually approximately 2 to 3 weeks, followed by protected range-of-motion activities. Isometric quadriceps exercises are prescribed throughout the immobilization period to minimize atrophy and the effects of disuse. Interval radiographs are obtained to ensure maintenance of fracture reduction.17
There are many advocates for closed reduction by knee extension under anesthesia18,19,20 followed by immobilization of the knee for type II fractures of the tibial spine. There has been heavy debate regarding the ability of manipulation under anesthesia to cause anatomic reduction.4,19,20,21 Reduction during manipulation is most likely caused by femoral notch and sulcus pressures during knee extension. Importantly, a minimal amount of fragment elevation (<4 mm) does not appreciably affect subjective knee outcomes.10,22 Often, the inability to achieve reduction with closed manipulation is secondary to entrapment of the medial meniscus and/or intermeniscal ligament in the fracture.23,24 If an acceptable reduction cannot be achieved or maintained by closed manipulation, operative treatment is indicated.
Surgical reduction and fixation is standard of care in types III and IV fractures, and soft tissue entrapment occurs in 65% to 100% of these fractures.23,24 A systematic review of treatment of tibial spine fractures in pediatric patients revealed a significantly high rate of nonunion in types III and IV tibial spine fractures treated by nonoperative means.25 As such, the authors advise operative management of all types III and IV tibial spine fractures. There are several arthroscopic techniques that have been reported, including metal screw fixation, bioabsorbable screw fixation, staple fixation, K-wire fixation, suture fixation, and suture anchor fixation. Within the orthopedic community, questions regarding the strongest method of fixation with the most stability still remain,26 with some surgeons favoring suture fixation while others prefer screw fixation. Despite surgeon preferences, a recent systematic review of 26 articles reporting on treatment and outcomes of tibial spine fractures in pediatric patients revealed that the evidence for favoring screw or suture fixation is poor, with no appreciable benefits to one method over the other.25
The success of surgically treating tibial eminence fractures depends on secure fixation, early mobilization,27 and early treatment.8,28 Some biomechanical studies have reported that the strength of suture fixation is higher than that of screw fixation.29,30 However, other studies have found that both suture and screw fixation had increased fracture separation during cyclic physiologic loads which could cause loss of fracture reduction.31 More recently, reports have indicated that the use of a hybrid technique, using both suture and screw fixation, may achieve a more stable reduction, allowing early return to range of motion, thereby decreasing risk of arthrofibrosis.32