Floating Knee

Dr Rohil Singh Kakkar

1. FLOATING KNEE Dr Rohil Singh Kakkar Post Graduate Resident Dept. of Orthopaedics RHC , India

2. Definition   In 1975, Blake and McBryde established the concept of the ’Floating Knee’ (FK) to describe traumatic ipsilateral fractures of the femur and tibia, where the knee is disconnected from the rest of the limb .

3. Classification Fraser Classification (1978) of Floating Knee Injuries Type I 71 % Also known as True Floating Knee. Extra- articular fractures of both bones.

4. Type II It is subdivided into 3 groups, as follows: Type IIa ( 08 % ) - Tibia plateau fracture associated with a femoral shaft fracture.   Type IIb ( 12 % )- Articular fracture of distal femur associated with a tibial shaft fracture Type IIc ( 09 % ) – Fracture of the tibia plateau and articular fracture of the distal femur.

5. Mechanism   Usually a high-energy trauma (RTA) Collisions between cars ‘Knocked down’ pedestrians

6. Clinical Picture -The patient would present with injury to the limb or the injury may be found on assessment of a polytrauma patient , Therefore complete limb examination must be done. The neurovascular deficit must be specifically looked for as these fractures are frequently associated with damage to the vessels ( popliteal and posterior tibial arteries) and the nerves ( peroneal nerve) are common.

7. -The incidence of open fractures is 50-70%, at single or both fracture sites. Tibial # has a higher frequency of being open. Injury to the knee ligaments especially Anterolateral rotatory instability is commonly found. Knee joint injury is indicated by substantial hemarthrosis .

8. Prognosis The Karlstrom and Olerud Prognosis criteria are widely accepted for evaluating functional outcomes in adults.    The following data are recorded and characterized as excellent, good, acceptable, or poor.

9. Karlstrom and Olerud Prognosis Criteria

10. ASSOCIATED INJURIES Severe Head Injury Chest Trauma Abdominal Injury Popliteal Art Lesion Open # Neuro Vascular Injury Consideration of Hemodynamic stability is the first step prior to all.

11. ASSOCIATED INJURIES STATISTICS

12. Associated Meniscal & Ligament injuries In a Fraser type II knee, an MRI prior to surgery can help to indicate the need to proceed with an arthroscopy exploration and repair. Study and Statistical Analysis (n- 142 Patients) (Source – JOURNAL EFORT OPEN REVIEWS , VOL -1 , NOV 2016 ) After fracture fixation, clinical examination of the knee, as well as arthroscopy or direct exploration in open cases, were performed during the initial surgery.

13. They found 70.3% ligamentous injuries comprising: 57% ACL ruptures (6 complete, 15 partial) 8% PCL 27% MCL 19% LCL A Medial meniscal tear was present in 38%, And a Lateral meniscal tear in 30% of cases.

14. MANAGEMENT -These fractures are almost always produced by high-energy trauma and are often associated with other life-threatening conditions, as well as other fractures and varying degrees of soft-tissue lesion.  -Therefore, advanced trauma life support protocols should be followed rigorously and the patient stabilised before orthopaedic treatment can be considered. 

15. Consideration of Hemodynamic stability is the first step prior to all. The “Triad of Death" is a term coined to describe the decompensation caused by acute blood loss resulting in -Hypothermia Coagulopathy and Acidosis. The prevention or reversal of these factors may prevent death from exsanguination .

16. The use of external fixation as an initial approach avoids the need for more time-consuming procedures that can worsen the "triad of death". Procedures lasting more than six hours are particularly dangerous, as they are associated with higher rates of acute respiratory distress syndrome(ARDS) and multiple organ failure. It is essential to diagnose the lesions associated with floating knee because they may be life threatening. 

17. The MESS (Mangled Extremity Severity Score) scale takes into account: (1) Skeletal and soft-tissue injury; (2) Limb ischaemia ; (3) Shock; (4) Patient's age. This tool has proven to be useful in the clinical and legal management of such lesions

18. As mentioned above, associated injuries (head, chest or vascular injuries and other fractures) play a significant role in surgical decision-making regarding the timing and sequence of surgery. Damage control treatment for floating knee involves not only bone stabilisation using an External Fixator and the treatment of open fractures by wound cleansing and debridement, but also, The treatment of associated lesions such as vascular injury or compartment syndrome, in which the corresponding fasciotomy must be performed.

19.   Fraser type IIb floating knee. Damage control by External Fixation in each segment.

20. DEFINITIVE TREATMENT Femoral nailing is performed first, while the tibia is temporarily stabilised with an external fixator . Reason : If the tibia were stabilised first, the movement and deformation of the femur during surgery would cause greater damage to the soft tissues and pose an increased risk to the patient’s general condition, including the increased incidence of fat embolism.

21.  Fraser type I floating knee. IM Nailing in the two segments done .

22. In type II floating knee, affecting the joint, it is crucially important to perform anatomic reduction of the articular surface. Metaphyseal-diaphyseal stabilisation can be performed indirectly, and minimally invasive fixation achieved by means of locking plates.

23. CASE CASE 1 : 20 YRS/ MALE , H/O RTA. NO NEURAVASCULAR DEFICIT. IMMEDIATE XRAY DONE S/O : FLOATING KNEE GRADE 2B

24. IMMEDIATE POST- OP XRAY

25. 3 YEARS POST OP XRAYS

26. CLINICAL PHOTOGRAPHS OF SAME PATIENT AT 3 YRS FOLLOW UP SHOWING RANGE OF MOTION.

27. CASE 2 : 21/M , H/O RTA XRAY – FLOATING KNEE GRADE 2B

28. IMMEDIATE POST OP XRAY AFTER DISTAL FEMUR PLATING AND TIBIA IM NAILING

29. 2 YRS POST OP XRAYS SHOWING FRACTURE UNITED WITH IMPLANTS IN SITU

30. CLINICAL PHOTOGRAPHS OF SAME PATIENT AT 2 YRS FOLLOW UP SHOWING RANGE OF MOTION

31. CASE 3 ( A) Type 2C floating knee. ( B ) The femoral fracture was treated with dynamic compression screw and the tibial fracture was treated with plating. Union occurred 12 months postoperatively.

32. COMPLICATIONS A- EARLY COMPLICATIONS

33. B- LATE COMPLICATIONS

34. SOURCE AND REFERENCES 1. Blake R, McBryde A Jr. The floating knee: ipsilateral fractures of the tibia and femur. South Med J 1975;68:13-16. 2. F raser RD, Hunter GA, Waddell JP. Ipsilateral fracture of the femur and tibia. J Bone Joint Surg [ Br ] 1978;60-B:510-515.

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