1. INCIDENCE OF INTERNAL DERANGEMENTS OF KNEE WITH IPSILATERAL FEMORAL SHAFT FRACTURE ABSTRACT NUMBER : 120

2.  Diaphyseal femur fractures are mostly the result of high energy trauma.  Femoral shaft fractures are often associated with bony and soft tissue injuries to the ipsilateral knee, and a high index of suspicion is necessary to identify these lesions.  These ligament injuries are usually silent or occult and many of them progress undiagnosed at this stage, with negative consequences for patients and orthopedicians. INTRODUCTION

3.  Assessment of the ligaments of the knee by clinical examination in the emergency room is difficult to perform as the distal segment of the fractured femur is unstable; and movement of the affected knee may cause more pain or discomfort to the patient.  The clinical methods to assess the knee joint for intraarticular soft tissue injuries are either under anesthesia preoperatively or after fixation postoperatively.  The disadvantage of examination under anesthesia preoperatively is meniscal injuries cannot be assessed optimally.  Hence we hypothesised that a preoperative MRI of the affected knee joint, will aid in the diagnosis of a soft tissue injury.

4. OBJECTIVES  To anticipate meniscal, ligamentous and retinacular injuries of the knee in patients sustaining ipsilateral femoral shaft fractures.  To identify the type and character of intraarticular ligamentous injuries of the knee joint following ipsilateral femoral shaft fractures.  To emphasize the need for an MRI of the knee with ipsilateral femoral shaft fractures in the preoperative period.  To establish the advantages of MRI knee in tailoring the management strategy of femoral shaft fracture and to address the issue of intraarticular soft tissue injuries.

5. METHODOLOGY STEP 1 Patients with femoral shaft of femur fracture Patients fulfilling the inclusion criteria and exclusion criteria were selected STEP 2 Patient explained about the advantage of the investigation Written consent was obtained STEP 3 MRI of ipsilateral knee was done and findings were noted All findings were tabulated in a master sheet and incidence was calculated.

6. Methodology INCLUSION CRITERIA : 1) Age group: >15 years. 2) Patients with fracture shaft of femur. EXCLUSION CRITERIA: 1) Patients with periprosthetic, pathologic fractures or polytrauma. 2) All patients with previous knee injuries or previous knee surgery. 3) Patients on cardiac pace makers or metal implants. 4) Any other contraindications for an MRI.

7.  Out of 40 patients, there was incidence of intraarticular soft tissue injuries in 26 patients (65%). RESULTS

8. InjuryNumber of Cases Anterior cruciate ligament Complete tear Partial tear Total ACL 8 (20%) 5 (12.5%) 13 (32.5%) Posterior cruciate ligament Complete avulsion Complete tear Partial tear Total PCL 2 (5%) 5 (12.5%) 9 (22.5%) Medial collateral ligament (MCL) Complete tear Partial tear 4 (10%) 2 (5%) Lateral collateral ligament (LCL) Complete tear Partial tear 4 (10%) 2 (5%) Menisci Medial Anterior horn Posterior horn Lateral Anterior horn Posterior horn Total menisci 10 (25%) 1 (2.5%) 5 (2.5%) 6 (15%) 2 (5%) 16 (40%) Extensor mechanism Patellar tendon partial tear Patellar tendon complete tear Quadriceps tendon partial tear Total extensor mechanism 1 (2.5%) 2 (5%) 4 (10%) Retinacular tears3 (7.5%) Cartilage0 (0%) Bone Contusion Occult fracture 32 (80%) 3 (7.5%)

9. NUMBER OF CASESPERCENTAGE Effusion40 / 40100 % Bone contusions32 / 4080 % ACL injury13 / 4032 % PCL injury9 / 4022 % MCL injury4 / 4010 % LCL injury4 / 4010 % Medial meniscus injury10 / 4025 % Lateral meniscus injury6 / 4015 % Capsular tears3 / 408 % Patellar tendon injury2 / 405 %

10. STRUCTURE INVOLVEDNUMBER OF CASESPERCENTAGE ACL4 10 % PCL4 10 % LCL1 2.5 % MCL3 7.5 % MM2 5 % LM1 2.5 % MM + LM1 2.5 % ACL + PCL2 5 % ACL + MM2 5 % ACL + PCL + MM1 2.5 % ACL + PCL +LCL + MM + LM1 2.5 % PCL + LCL + MM1 2.5 % ACL + PCL + LM1 2.5 % ACL + LCL + MM + LM1 2.5 % ACL + MM + LM1 2.5 % No ligamental or meniscal injury14 35 % TOTAL NUMBER OF CASES40 100 %

12. De Campos 1994 (Arthroscopy) Blacksin 1998 (MRI) Dickson 2002 (MRI) Our study 2014 (MRI) Number of patients 40342740 Total abnormal22 (55%)34 (100%)+19 (70%)26 (65%) ACL21 (53%)2 (6%)5 (19%)13 (32.5%) PCL3 (7.5%)7 (21%)2 (7%)9 (22.5 %) LCL5 (12.5%)2 (6%)8 (30%)4 (10%) MCL11 (27.5%)13 (38%)11 (41%)4 (10%) Total meniscus13 (32%) knees10 (30%)11 (41%)16 (40%) Lateral meniscus8 (20%)4 (12%)7 (26%)6 (15%) Medial meniscus5 (12%)6 (18%)4 (15%)10 (25%) Bone bruiseN/A 32% 1 (3%) occult tibial plateau fracture 25 (93%)32 (80%) EffusionN/A33 (97%)N/A40 (100%)

13. Why a pre-operative MRI? Why not post-operative MRI?  In order to reduce the error factors addressed in the previous studies like iatrogenic MCL tears during interlocking screw fixation,  MRI of patients with stainless steel induced artifacts in retrograde intramedullary nailing were excluded in the previous study, which may have caused variation in the true incidence of internal derangements of the knee.

15. Antero – Lateral ligament (ALL)

16. ALL injury in MRI Proximal ALL injuryDistal ALL injury

17. Incidence of ALL injury in our study Incidence – 11 cases (44%)  Proximal ALL injury – 4 cases (16%)  Distal ALL injury – 5 cases (20%)  Proximal + Distal ALL injury– 2 cases (8%)

18. Conclusion  Femoral shaft fractures exerted by high velocity forces have been proven to cause internal derangements in the ipsilateral knee along with soft tissue injuries, by exhaustive analysis by various orthopedists, radiologists through physical examination, X-rays analysis, MR imaging and arthroscopic evaluation.  The incidence of internal derangements of the knee in our study using MRI is similar to those reported in the previous studies using arthroscopy and/or MRI as diagnostic tools.

19. MR imaging of the knee is considered advantageous to have shown  a significant increase in the incidence of ligamentous injuries in the knee from 5% in earlier studies to 70% in recent studies;  in the identification of clinically suspected meniscal injuries through a non-invasive approach;  and a suitable non- radiational imaging modality for arthroscopic blind spots.

20.  In a case of femoral shaft fracture due to a high velocity trauma, the attending surgeon must beware of an internal derangement of the knee and must investigate for knee instability, ligament laxity.  Currently there is no general consensus on the use of the MRI scan as a standard diagnostic preoperative tool. It is usually preserved for patients who develop joint instability or soft tissue related symptoms(knee locking, persistent joint pain) at a secondary stage following fracture healing and weight bearing. Take home message