Fractures

MDS1008 CTS 4A Fractures and dislocation of the hip , congenital dislocation

of the hip

Case 1A 72 year old widow who lives with her oldest daughter is found on the floor of herbedroom, having tripped on a carpet. She complains of severe pain in her right hip and is unable to get up. An ambulance is called to take her to the hospital. On examination she appears frail and thin. Her right leg is externally rotated and 2. 5 cm shorter than the left leg. She is unable to lift up the right heel. The greater trochanter on the right side appears higher and more prominent than on the left. On palpation there is tenderness in the femoral triangle in front of the hip joint. A provisional diagnosis of fracture through the femoral neck is confirmed by AP and lateral X Rays of both hips.

Questions 1. Explain the anatomical basis for the clinical findings.

Leg externally rotated: depends of change of muscles activity. Main flexor of the hip is the iliopsoas (attaches to the lesser trochanter). Also causes medial rotation (also due to adductors. Fulcrum normally pulls inwards… but in fracture the fulcrum pulls outwards.

Leg shorter on one side: to measure length of the leg: use landmark. pelvis and distal leg... use medial malleolus...Pull of muscle Rectus femoris, Adductor muscles, Quadriceps... attached proximal to the hip joint... therefore pull distal part proximally. Normally head of femur in actebulum therefore cannot

be pulled proximally.

Tenderness in fem triangle: has the head of the femur... can be palpated... pain in arthritis. Reason for tenderness.

Higher greater trochanter: more obvious due to pushing out... normally attached to gluteus medius and minimus (medial roation/abduction)... bone not attached so pulled outwards.

2. Assuming that the X Ray shows the fracture is just below the head of the femur (subcapital), describe the position of the fragments.

The strong muscles of the thigh - including the rectus femoris, the adductor muscles, and the hamstring muscles, pull the distal fragment upward thus the reason why the leg is shortened.

Head remains where it is but medially rotated.

3. Why is it important to X Ray both hips?

To compare the right and left hip - one injured hip and one normal (normal as in this particular woman) hip.Weak bones... Osteoporosis... Arthritis...Fracture hip: want to get patient walking again as soon as possible... Normally have to replace the head of the femur in a painful, expensize and extensive surgery, therefore better to know of risk to both hips so you can know what action to take early on.

4. What is Shenton’s Line?

A curved, continuous artificial line formed by the top of the obturator foramen and the neck of the femur, seen on an AP radiograph of a normal hip joint. It is a rapid way of testing dislocation and fractures.Smooth: nothing wrong.Not smooth: dislocation/fracture.

o 5. What else might you expect to find on X Ray examination of the hip? How may this be related to the history in this case?

In Osteoporosis: a simple trip in a young person is not that serious and normally will not cause fractures of this type... (DARKER decreased density)In elderly: a small fall can result in fractures... due to weaker bones. Common areas are hip, vertebrae and colles.

Tenderness on the femoral triangle shows signs of arthritis. Arthritis can be seen on the X-ray - this is observed by the bones being close to each other due to the wearing out of the smooth cartilage between bones - the function of this cartilage allows the bones to move smoothly against each other.

6. Explain how the blood supply to the femoral head may become compromised by a subcapital fracture. What are the possible consequences?

Fractures of the femoral neck interfere with or completely interrupt the blood supply from the root of the femoral neck to the femoral head. The scant blood flow along the small artery that accompanies the round ligament may be insufficient to sustain the viability of the femoral head and ischaemic necrosis gradually takes place.

o Blood supply: no connection between top and bottom part due to the epiphyseal line made of cartilage (which is avascular) in under 14 y/o.

o Bottom part 2 big anastamoses: cruciate/trochanter anastomosiso 14y/o and over when there is formation of bone connection restored

due to bone marrow… o In elderly: BM yellow marrow. Artery has now shrunk. Only small

part is supplied… small artery runs along reflective part.

o Reflected capsule edges of acetabulum to lesser and greater trochanter and is reflected along the neck blood vessel then runs along the reflected part… runs close to the neck…

o in fracture blood vessels are torn AVN/ischaemic necrosis(unlikely they will line up and heal even after in hemiarthroplasty).

7. How do intertrochanteric and subcapital fractures differ from each other?

Intertrochanteric fracture – occurs in young and middle-aged people due to direct trauma. There will be no avascular necrosis complication as in subcapital fractures as the fracture line is extracapsular and both fragments will have a profuse blood supply.

Subcapital fracture – occurs in elderly even with a minor trip, especially in postmenopausal women as the oestrogen deficiency causes the bone to thin more than in elderly males. Complication: avascular necrosis of head of femur. Risk of AVN is higher. Occurs mostly due to osteoporosis.

8. Assuming that the hip is pin and plated or the joint is replaced, what factors are likely to help or hinder her recovery?

Help recovery: early mobilization, physical therapy, using a walking aid, not putting too much stress on the affected area – not spending a lot of time on her feet and exerting herself. Encourage movement and activity to prevent atrophy of the muscles… take into consideration lifestyle.

Hinder recovery: the fact that she suffers from arthritis, any tumour or metabolic condition (eg: osteomalacia) developing in bones,

development of osteoporosis, increased weight, side effects of certain drugs she may be taking.

Case 2A 65 year old overweight woman complains of pain in the right hip area for severalmonths. She is unable to walk to church and to the shops because of pain, and is now house-bound. On examination she weighs 150 kg. Movements of the hip are limited. An X Ray examination shows decreased joint space, erosion of the articular cartilage and osteophytes at the joint surface.

Questions 1. Explain the clinical findings in anatomical terms.

The hip bone consists of 3 bones: ilium, ischium and pubis. These meet at the acetabulum which articulates with the head of the femur to form the hip joint. The restricted hip movement and Xray findings indicate osteoarthritis. Age is the main contributing factor for degeneration of the protein in cartilage while the water content increases. Another factor that makes her susceptible to this condition is the fact that she is overweight.

Pain: bone rubbing against bone… occurs in osteoarthristis… rubbing hard on the bones eventually removes the cartilage… stem cells of cartilage are found on the surface therefore eventually lead to bone rubbing against bone. The lack of cartilage results in friction on movement as joint space is reduced and so bones are closer together. This causes swelling and pain, as well as limited joint mobility.

Limited movement: decreased joint space indicative of cartilage

being eaten away… The inflammation results in osteophytes. osteophytes: extra bone outgrowths forming. In a fracture: callus tries to fix fracture… where cartilage is lost, breakdown of the periosteum... Body thinks it has a fracture so produces more bone… which then keeps getting eaten at… get extra pieces of bone growing on the side of the bone pain.

2. What is the normal range of movements of the hip? How are these movements tested?

Flexion = up 180 degreesExtension = 0 to 30 degrees (backward movement of flexed thigh)… limited due to iliofemoral ligament… very strong.Adduction = 0 to 30 degrees. Abduction = 0 to 45 degrees: Used for walking by abducting body on leg and also balancing.External rotation = 0 to 60 degrees. Internal rotation = 0 to 40 degrees. Movement of rotation is used to change direction when walking…Circumduction:

3. In what ways does her weight negatively impact this disease?

Her weight increases the load on her hip which is already arthritic due to her increasing age, as well as loss of bones due to rubbing. The excess weight also creates more mechanical stress on the degenerating cartilage.

4. Assuming she uses a stick to assist in walking, in which hand would she hold the stick and why?

In her left hand since her right hip is affected and one should always hold a stick/cane on the opposite side of the body to the affected joint. This takes some pressure off the affected joint and relieves some of the symptoms. Always used the opposite hand to the leg affected. Due to push of center of gravity when walking.

Case 3

An 18 year old law student is involved in a head-on road traffic accident. He is not wearing a seat belt. When he is extracted from the vehicle, he complains of being unable to move the left ankle and foot. The left leg is 3 cm shorter than the right and it is adducted and medially rotated. The left hip is very painful. There is contusion over the left knee. On examination, he is unable to extend the hip joint, flex the leg or move the ankle and foot in any direction (Hamstrings). There is loss of sensation over the posterolateral part of the leg (sural / lateral cutaneous nerve of the thigh) and almost the whole foot. There is a large painful mass in lateral gluteal area.

Questions 1. What might you expect to find on X Ray examination of the hip?

Indicative of a hip dislocation. Would see medial rotation: therefore NOT a fracture (fractures cause external rotation)… caused by femoral head not moving (causes the mass in gluteal region). Head of femur has come of out of the acetabulum…

2. Describe how this injury occured in this case? How else could this injury have happened?

Since he wasn’t wearing a seatbelt, the patient ended up hitting his knee against a part of the car (explains the knee contusion). The force of the collision was transmitted to the head of the femur pushing it out of place and possible fracturing the acetabulum in the process. Could have also been caused by a fall from height, such as falling from a ladder. Some congenital disorders may also result in hip dislocation. These include Chromosome 9 trisomy, Cutis Laxa Debre Type, and De Barsy Syndrome.

3. Describe the anatomical basis for the clinical findings in this case.

Medial rotation…

The fact that he cannot move his left ankle and foot shows that there is damage to the nerve supplying the muscles responsible for this movement. This nerve is the sciatic nerve supplies post thigh and muscles below the knee… head of femur squashing sciatic nerve no movement below the knee.

4. Why is he unable to extend the hip joint? Which hip extensor might still be functional and why?

This is because maybe the sciatic nerve has been injured and the hip extensors (biceps femoris, semitendinosus and semimembranosus) are all supplied by the sciatic nerve.The only remaining extensor is the Gluteus maximus. It can still extend the hip since it is supplied by a different nerve, the inferior gluteal nerve.Quiet extension: hamstrings main extensor

Running/jumping/climbing: Gluteus Maximus main extensor… pulls more distally. Due to its insertion allows for larger burst of extension.

5. Why is the leg shortened, adducted and medially rotated?

The leg is shortened since the hip has been dislocated pushed inwards by the impact.

It is adducted and medially rotated due to injury to the abductors and lateral rotators which cannot contract, leaving the abductors and medial rotators unopposed.

6. What factors may affect the clinical features in this case?

Whether there are other injuries such as vertebral column fractures pinching on the nerve roots which would impair function of the muscles but hide the sciatic nerve injury.

7. If this nerve were to be involved in disc prolapse, in what ways would the clinical features be the same, and how would they differ?

They would be the same since:

3 flexors and extensors of the leg would still not function, as would the ankle and foot since the tibial nerve and deep fibular nerve (from the common fibular nerve) are both derived from the sciatic nerve.

They would differ since the patient would also suffer from

back pain. Besides the sciatic nerve other nerves would be injured such as the pudendal nerve, the nerve to inferior gluteus and the nerve to piriformis.

8. Apart from disc prolapse, how else could this nerve be affected?

The Sciatic nerve may be injured in a number of ways commonly by compression or section (slicing of).

Compression may be caused by Pirriformis syndrome in which the small gluteal muscle, pirriformis, hypertrophies and starts to spasm compressing on the sciatic nerve when this nerve passes through it, Pelvic fractures at the Pelvic brim region, and tumors medial to said sciatic nerve, in this case the tumor would compress the nerve against the pelvic girdle increasing damage as the tumor grows.

Section of the Sciatic nerve is uncommon and can either arise from physical attack(stab wounds) or it may be iatrogenic, caused during a surgery in the medial side of the buttock. In each case different levels of loss of function may occur, from loss of inferior gluteal movement and posterior femoral cutaneous nerve sensation, up to complete loss of extension and flexion, with loss of function of knee and ankle joints.

9. What ligaments support the hip joint? In a patient with posterior dislocation of the hip, which of these would be torn and why? Which artery is the main blood supply to the hip joint?

The Hip joint is supported by three intrinsic joints, which

restrict its movement while keeping it in place. They are the iliofemoral ligament (anteriorly and superiorly to the hip joint, extension), pubofemoral ligament (anterioly and inferiorly to the hip joint, extension and abduction) and ischiofemoral ligament (posteriorly to the hip joint). It is also held by the transverse acetubular ligament (acetubular labrum) and the femoral head ligaments (found circumferential around the head of the femur), these two ligaments fuse to help in general stability.

In posterior dislocation the anterior ligaments must be torn to allow for posterior movement, since if they are still fully functioning they would not allow the head to dislocate backwards. Since the most powerful anterior ligamnents are the iliofemoral and the pubofemoral, they must be torn to accommodate this type of injury.

The hip joint is supplied by the circumflex arteries of the femoral head. It is supplied by both lateral and medial branches.

10. What is congenital dislocation of the hip? How should this be checked in a newborn?

Congential dislocation of the hip is a type of Developmental Dyslapsia of the Hip(DDH) in which the different parts of the hip joint do not develop completely resulting in lack of contact between the femoral head and the acetabulum. It can arise from both abnormal growth of the femur and due to extremely lax ligaments, in each case the hip joint is made null due to defective components.

The condition in a newborn can be diagnosed by following simple procedures. The Ortolani maneuver in which the abducted hip is reduced into the joint, will cause a palpable low pitched clunk in infants with DDH. Also in unilateral dislocation leg legth differences and abduction of affected leg may be observed. (A child at an older age(3-6 months can be diagnosed using the Galeazzi sign).

Different treatments are recommended for different types of dislocations at different age groups depending on their relative percentage of success.Surgery for the hip joint is only recommended in cases in severe cases of DDH in which natural repair is not viable.Normally with infants if instability is found a brace (Pavlik's harness is used).

In unilateral dislocation(w/o pain) the child, if the dislocation is mild would probably walk normally with a slight limp.

Indeed a case of a 74 year old man who was diagnosed with bilateral congenital dislocation only a few months prior to his death.

11. What treatment would be recommended? If the dislocation is not diagnosed at treated at birth, describe the way a patient with this condition would walk as a child.