Non union neck of femur

non union neck of femur in detail

1. NON UNION NECK OF FEMUR DR RAMACHANDRA Under the guidance of Prof. A. Devadoss Dr. Sathish Devadoss

2. INTRODUCTION ANATOMY CLASSIFICATION CAUSES FOR NONUNION NOF INVESTIGATION TREATMENT

3. INTRODUCTION Fractures of the neck of femur in young adults tend, unlike their counterparts in older people, to be a relatively higher-energy injury and require timely and meticulous diagnosis and management. Anatomical reduction and stable internal fixation are essentials for achieving the goals of treatment in this young population.

4. The U.S. Food and Drug Administration panel defined nonunion as “established when a minimum of 9 months has elapsed since injury and the fracture shows no visible progressive signs of healing for 3 months.” A fracture of the femoral neck sometimes can be defined as a nonunion after only 3 months.

5. A delayed presentation of fracture of the femoral neck is one where there is a delay of 48 hours to 20 days between injury and diagnosis, whereas in a neglected fracture , this delay is in excess of 21 days.

6. The main complications of such injuries are avascular necrosis (AVN) of the femoral head and non-union of the fracture with reported average incidences of 15% for AVN and 12% for non-union

7. At birth main supply-lateral epiphyseal and metaphyseal vessels 4month-4year Exclusive supply from lateral epiphyseal vessels Cartilaginous growth plate is barrier. 4 to 7 year Exclusive supply by the lateral epiphyseal artery Epiphyseal plate is firm barrier More than 7year Vessels from the ligamentum teres penetrate and join the lateral epiphyseal vessels Cartilaginous growth plate is still barrier.

8. BLOOD SUPPLY Crock described three major groups of vessels Extracapsular arterial ring Ascending cervical branches of arterial ring Artery of ligamentum teres

9. CAPSULAR VESSELS Arise from the MCFA & LCFA which are in turn branches of the profunda femoris in 79% of cases. In 20% arises from the femoral artery. In 1% both vessels arise from the femoral artery.

10. The MFCA & LCFA form an extracapsular circular anastomosis at the base of the femoral neck, and the ASCENDING CERVICAL CAPSULAR VESSELS arise from this.

11. They penetrate the anterior capsule at the base of the neck at the level of the intertrochanteric line. On the posterior aspect of the neck, they pass beneath the orbicular fibers of the capsule to run up the neck under the synovial reflection to reach the articular surface.

12. Within the capsule these are referred to as RETINACULAR VESSELS. There are four main groups (anterior, medial, lateral, and posterior) of which the lateral group is the largest contributor to femoral head blood supply.

13. The most important retinacular vessels (lateral group) arise from the deep branch of the medial femoral circumflex artery. These vessels supply the main weight-bearing area of the femoral head.

14. SUBSYNOVIAL INTRA-ARTICULAR ARTERIAL RING At the articular margin of femoral head Formed by vessels that penetrate the head ( epiphyseal arteries) Lateral epiphyseal vessels supplying lateral weight bearing portion most important Joined by vessels from ligamentum teres .

15. ARTERY OF LIGAMENTUM TERES Branch of Obturator artery or Medial circumflex femoral artery Gives blood supply to a small area of head of the femur Contribute little blood supply to femoral head until age 8 and then only about 20% as an adult . Not sufficient to maintain blood supply of femoral head.

16. CLASSIFICATION Sandhu described a classification system for NU/neglected femoral neck fracture incorporating changes at various stages. Based on changes, he classified the neglected femoral neck fracture into 3 types (described as 3 stages).

17. The radiological findings are: Stage I a. Fracture surfaces are still irregular (irregular or jagged) b. The size of the proximal fragment is 2.5 cm or more c. Gap between the fragments is 1 cm or less d. Head of the femur is viable with no sign of AVN on X‑ray or MRI.

18. Stage II a. Fracture surfaces are smooth and sclerosed b. The size of the proximal fragment is 2.5 cm or more c. The gap between the fragments is more than 1 cm but <2.5 cm d. The head of the femur is viable.

19. Stage III a. Fracture surfaces are smoothened out b. The size of the proximal fragment is <2.5 cm c. The gap between the fragments is more than 2.5 cm d. The head of the femur shows signs of AVN.

20. CAUSES Why is non union common after fracture neck femur NOF? i . Absence of cambium layer of periosteum of femoral neck leads to decrease in the healing potential ( Phemister , 1939). ii. Continuous Synovial bathing. iii. Avascularity as healing callus comes from the neck shaft side the fracture because of avascularity of the head ( Hulth 1961). iv. High velocity trauma in young adults.

21. Factors contributing to nonunion of femoral neck i . Inaccurate reduction. ii.Loss of fixation. iii.Vascular insufficiency. iv. Posterior comminution . v. No treatment

22. CLINICAL FEATURES Neglected femoral neck fracture presents with shortening, severe external rotation of the lower extremity, upward displacement of the trochanter , with or without soft tissue contracture.

23. Tenderness over mid inguinal point Telescopy test positive, trendelenburg’s positive. In malunited intertrochanteric fracture : There should be irregularity over trochanter with broadening and thickening. Tenderness should be at trochanteric region rather than mid-inguinal point.

24. INVESTIGATION i . Plain X-rays. ii. Bone Scanning. iii. Tomography or high resolution CT scan. iv. MRI.

25. X‑ray of pelvis including both hip joints in the identical position should be taken to classify neglected femoral neck fracture. The length of the proximal fragment is measured from upper margin of fovea centralis to the midpoint of fracture margin.

26. Plain X‑ray pelvis with both hips helps to make a clinical diagnosis and stage the neglected femoral neck fracture.

27. CT Scan- provides the best assessment of fracture union It is useful to see the  Bony appearance of stippled area  Bony sclerosis  Trabecular resorption  Microfractures  Subchondral collapse

28. MRI- mainly useful to assess the viability of femoral head Bone scan- to differentiate between AVN and nonunion

29. TREATMENT The goal of treatment in neglected fracture NOF is to achieve A painless, mobile and stable hip.

30. The treatment depends on : Age and physical status of the patient, Duration of NU, viability and spherocity of the femoral head, Amount of resorption of the femoral neck potential limb length inequality.

31. Treatment modality vary both in elderly and in young adults Replacement arthroplasty is the treatment of choice for elderly pts in nonunion neck of femur

32. In young adults efforts are focused on preserving the femoral head. It is broadly categorised into: Head salvaging procedures Head sacrificing procedures

33. Head salvaging procedures : If femoral head is viable and adequate neck is remaining nonunions can be treated by - Fixation alone - Osteotomy +/- fixation - Muscle pedicle bone grafting +/- fixation - Cortical bone grafting +/- fixation - Cancellous bone grafting +/- fixation - Combination of osteotomy and bone grafting

34. The methods of treating nonunion aim either at improving the biology and bone stock ( i.e., non vascularized and vascularized bone grafts muscle pedicle graft) or improving the biomechanics ( i.e., valgus osteotomy )

35. VALGUS OSTEOTOMY The concept of valgus osteotomy was refined by Pauwels in 1927. According to his findings showing that nonunion NOF was due to the high shear forces that increased with the vertical orientation of the fracture. The proposed biomechanical solution was to redirect these forces into compression forces via an angulation osteotomy and fixation with a blade plate device.

36. Valgus intertrochanteric osteotomy as described by Pauwel . Modified by Muller. Still today remains a popular treatment option as it has a high success rate and corrects the common symptoms of coxa vara and associated limb length discrepancy .

37. Marti et al helped to popularize the valgus intertrochanteric osteotomy for nonunion NOF by reporting good outcome in a long-term follow-up study. Marti RK, Intertrochanteric osteotomy for non-union of the femoral neck. J Bone Joint Surg Br 1989;

38. POTENTIAL PITFALLS Excessive valgus orientation: Often the calculated angle to convert a Pauwels 3 to Pauwels 1 may be as high as 40-50 degrees. Removal of such a large wedge will cause the osteotomy to inevitably extend from the intertrochanteric region into the subtrochanteric , which may cause further distortion of the femoral anatomy and abduction as well as external rotation deformity.

39. valgus of > 30 degrees can compromise the blood supply and increase the risk of AVN. Excessive valgus could also make a salvage total hip replacement extremely difficult.

40. Muscle pedicle bone graft +/-fixation Various muscle‑pedicle based grafts are described. Posterior approach is used for Quadratus Femoris based MPBG. Tensor Fascia Lata and Gluteus medius based MPBG is done in lateral or supine position by lateral or anterolateral approach.

41. Myoperiosteal grafting for inducing osteogenesis is reported for where the Quadratus Femoris pedicle is lifted with a strip of periosteum from neck and is placed across the fracture.

42. The author opined that anatomical reduction is not mandatory for fracture union, provided its vascularity has been restored. muscle‑pedicle bone graft seems to accelerate the union of fresh intra‑capsular fractures

43. Meyers and Harvey reported the results of their technique for delayed union. 9 years later Bakshi reported. Originally Bakshi had described fixing the graft with pins and threads, however in later series screws were used for fixation. In the present analysis, the fracture united in 92% cases.

44. By meyer et al(1974) Useful in delayed presenters as well as nonunion Quadratus femoris muscle insertion to the femur is mobilised with femoral cortex and is fixed across the fracture site posteriorly  11% segmental collapse at 2 years  90% union rate

45. Meyer’s graft . A: “T” incision of the posterior capsule. B : Mapping out the quadratus femoris graft . C : The trough is curetted out from the intertrochanteric lineup into the femoral head. A small tunnel is created up under the articular surface of the femoral head to lever the graft into position. Once the graft is inserted, a 3.5-mm cancellous screw and washer is inserted from posterior to anterior to compress the graft and support the comminuted posterior cortex.

46. By Bakshi (1983,86,92 ) Used gluteus minimus with attached bone block fixed anteriorly Used in proven nonunions with absorbed necks 75% good results

47. Closed/open reduction, internal fixation and single or double fibular grafting In this procedure closed or open reduction and CCS fixation of the fracture is performed after freshening the fracture surfaces. Fibula being cortical bone provides mechanical strength besides stimulating the union and getting incorporated as a biological graft.

48. Once the graft is revascularized , the osteoblasts stimulated by bone morphogenic protein replace the resorbed bone. Nonvascularized fibular strut graft along with cancellous screws provides a dependable and technically less demanding alternative procedure for neglected femoral neck fractures in young adults.

49. Vascularized fibular graft are reported to give superior result; however, it consists of microvascular anastomosis that is technically more demanding. Leung and Shen obtained 100% union and satisfactory clinicoradiographic result at 5-7 years follow up using vascularized iliac bone graft augmented by screw fixation.

50. THREE IN ONE PROCEDURE In this procedure 1. with dynamic hip screw 2.valgus osteotomy at lesser trochanteric level 3.Nonvascularized Fibular strut graft. This procedure helpful in Sandhu classification type 1 and type 2.

51. PRE AND POST OPERATIVE

52. PRE AND POST OPERATIVE

53. HEAD SACRIFICING PROCEDURES : Bipolar arthroplasty Total hip arthroplasty

54. Total hip arthroplasty

55. THR- is the treatment of choice in cooperative, independent individual with normal life span Hemiarthroplasty - done in pt with much less demand and leading a sedentary lifestyle

56. Valgus osteotomies and total hip arthroplasty The advantages of valgus osteotomy are manifold and include preserving bone stock and avoiding total hip arthroplasty (THA) in young patients. THA in young patients is associated with higher complication rates,such as prosthesis loosening and infection, as well as higher revision rates.

57. UNCEMENTED THR IN FAILED VALGUS OSTEOTOMY Entry point care should be taken so as to avoid reaming a false passage. While broaching care should be taken to negotiate over the tracts cut by the previous implants where a bridge of bone tends to form.

58. An uncemented stem should have a distal fit and extend distal to the previous screw holes. The trochanteric fragment may remain as a nonunion and may have to be separately reattached to the femur. If the proximal femoral anatomy is grossly altered, due to a subtrochanteric osteotomy , a corrective osteotomy may be required

59. When there is a defect of the posteromedial cortex, use of special modular or calcar replacing stems may be required.

60. CEMENTED THR IN FAILED VALGUS OSTEOTOMY Care should be taken during cementation to pressurise the screw holes externally, as the cement can track out and cause devascularisation of the sandwiched bone. However they have been shown to have increased complication rates in terms of survival and infection rates as compared to primary total hip replacements. Hip arthroplasty for salvage of failed treatment of intertrochanteric hip fractures. J Bone Joint Surg Am 2003;

61. Decision making Late presenters Irrespective of vascularity of head, good reduction achieved and neck-shaft angle maintained & If presented within 3 wks – Fix it If presented 3wks- 3months- fixation+ BG - MPBG If presented after 3months with shortening and varus of the head- Osteotomy +/- BG If there is segmental collapse- Replacement arthroplasty Arthrodesis

62. Treatment options for stage 1 Closed reduction & internal fixation Closed reduction & internal fixation with one screw and double fibular graft or two screws and one fibular graft CR or OR and bone muscle pedicle graft based on quadratus femoris or sartorius or tensor fascia Abuction osteotomy and osteosynthesis with DHS or 135degree anle blade plate or 120 degree double angle plate

63. Stage 2 OR, freshening of fracture surfaces and IF two screws and one free fibular graft ORIF with multiple screws and muscle pedicle bone graft Valgus osteotomy

64. Stage 3 Total hip arthroplasty Hemiarthroplasty Excision Artthroplasty

65. INDIAN JOURNAL OF ORTHOPAEDICS 2015

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