Ganglion Cyst

a) Ganglions, Ganglion Cysts –

 Account for 60-70% of soft-tissue tumours of the hand.
 The disease is common in females in their third and fourth decades.
 Usually arise adjacent to tendons. May also be intraosseous or intratendinous


Aetiology (theories):

– Formed by herniation of the synovial lining in which a one-way valve mechanism is created
– benign tumors of synovial origin
– A rent in the joint capsule or tendon sheath allows leakage of synovial fluid, which irritates surrounding tissue. This local tissue reacts by forming a pseudocapsule and subsequent ganglion
– Mucoid degeneration of connective tissue, with breakdown products of collagen collecting in pools, which coalesce to form large cysts.

Usual Sites
• Dorsum of the wrist (70%): in this location the origin is Scapholunate ligament. The dorsal ganglia are usually painless and they are found between the EDC and the EPL tendons.
• Volar wrist (20%): Deriving their origin from the radiocarpal (2/3rd) or STT (1/3rd) joints.
• Dorsum of the distal interphalangeal (DIP) joint-mucous cyst
• Volar aspect of a digit at the metacarpal phalangeal flexion crease (volar retinacular ganglion cyst). Arise from the A1 or A2 pulley of the flexor tendon sheath

Cyst fluid is gelatinous (apple jelly-like) with a high concentration of hyaluronic acid.
Microscopy: ganglia develop in stages as follows
1. First stage characterised by large number of spheroidal cells that are closely packed with a periphery of spindle cells
2. The second stage consists of spheroidal cells and spindle cells but with a central cavity filled partly with secretion from the spheroid cells.
3. Third stage, here the ganglion is well developed with a smooth wall resembling synovial membrane of joints. The walls of the larger cyst are poorly vascularised and the vessels show fibrosis of their wall suggesting a vascular aetiology for the development of these cysts.

Clinical Features:
Dorsal ganglion
• The mass is compressible, subcutaneous, transilluminating, slightly mobile, and without skin changes.
• Wrist extension often elicits pain at the site.
• Small dorsal ganglions may be palpable only in full wrist flexion.
• Occult ganglions are not palpable but may be quite painful.
• wrist pain, tenderness, and interference with activity

Volar ganglion:
• The mass is usually palpable between the radial artery and the flexor carpi radialis (FCR) tendon, or
• Adjacent to the scaphoid tubercle in the anatomic snuffbox or more distal in the palm.
• May arise ulnarly from the pisotriquetral joint and are palpable adjacent to the flexor carpi ulnaris (FCU) tendon.
• May compress the palmar cutaneous branch of the median nerve, median nerve or the deep branch of the ulnar nerve

Volar Retinacular Ganglion Cyst:
• Present as a small, very firm, minimally mobile mass near the proximal digital crease or metacarpophalangeal joint.
• do not move with flexor tendon excursion
• They are painful only when gripping a firm surface.
• Volar retinacular ganglions do not cause digital triggering, nor are they associated with trigger digits
• Can compress the digital nerve causing sensory disturbance.

Mucous Cyst:
• Gradually enlarging subcutaneous mass develops over the dorsal DIP joint.
• The lesion is firm and minimally mobile and can be transilluminated
• Lies typically lateral to midline, being displaced by the extensor tendon.
• Associated with osteoarthritis
• May rupture and get infected
• Nail deformity may develop from pressure on the germinal matrix.

Ganglions maybe associated with tendons, they are typically located in the dorsal wrist, extensor apparatus or the FCR in the volar wrist

Intraosseous ganglions of the hand and wrist: most common in the scaphoid and lunate.
On X-rays: The lesions appear radiolucent with a sclerotic border and frequently contact a joint surface without causing cortical expansion. Diagnosis is mainly of exclusion.



DD for dorsal wrist ganglion:
1. Ganglion of tendon sheath, giant cell tumor of tendon sheath, tenosynovitis of inflammatory or infectious origin, or an extensor digitorum brevis manus muscle belly.
2. The proximal pole of the scaphoid may be prominent dorsally in cases of dorsal intercalated segment instability,
3. The proximal pole of the lunate may be prominent in volar intercalated segment instability.
4. A firm mass more radial and slightly more distal may be an osteophyte from scaphotrapezial arthritis.
5. A compressible mass that decreases in size with elevation of the wrist may be a venous aneurysm

DD for volar ganglion:
1. Aneurysms of the radial or ulnar arteries
2. Intraneural cysts.

DD for volar retinacular ganglion cyst:
1. epidermoid inclusion cyst,
2. giant cell tumor of tendon sheath,
3. foreign body granuloma,
4. lipoma
5. Neurilemoma.

DD for mucous cyst:

1. Heberden’s node
2. Gout
3. Giant cell tumor of tendon sheath.

Diagnosis: is mainly clinical. USG and MRI also help in establishing a diagnosis

Wrist Arthroscopy has potential advantages in both diagnosing and treating an occult dorsal ganglion that is intra-articular and therefore visible from within the radiocarpal joint, and also provides information about other causes of dorsal wrist pain, such as synovitis, chondromalacia,
and scapholunate ligament tears


Treatment
Historical folk medicine has mentioned rupture with a mallet or Bible, methods that need not be considered except for their historical interest
i. cyst puncture and aspiration (High recurrence)

ii. Excision

Dorsal ganglia:



• Surgical treatment can be performed with the use of intravenous regional (Bier block) anesthesia,
• A transverse incision in Langer’s lines leaves a less noticeable scar than a longitudinal one
• The ganglion lies between the second and fourth dorsal extensor compartment
• Dissection is carried down to the joint capsule.
• When they are properly excised with a swath of joint capsule surrounding the stalk of the cyst, recurrence rates are less than 10% for dorsal cysts, and as high as 20% for volar cysts.
• It is important to maintain the overall integrity of the capsule and to not create secondary instability
• This lower recurrence rate may be due to the removal of a valvular mechanism or microcysts in the surrounding capsular tissue.

Volar Ganglia:
• Cyst puncture and aspiration is not recommended due to proximity to radial artery
• Surgical excision is preferred: Longitudinal incision just radial to the FCR tendon
• Branches of the lateral antebrachial cutaneous nerve and superficial radial nerve must be protected.
• The radial artery is carefully dissected free and gently retracted radially.
• If this dissection is difficult due to adherence of the cyst wall to the artery the technique of Lister and Smith maybe used
• According to Lister and Smith: one wall of the cyst is left attached to the artery while the remainder of the cyst and the stalk are excised.
• Ulnar sided volar ganglions are approached with a longitudinal incision along the radial border of the FCU tendon.


Volar Retinacular Ganglion Cyst:
• The mass is excised with a small window of tendon sheath, which is not repaired
• The neurovascular bundle is preserved.

Mucous cyst:
• Excision of the stalk of the cyst, removal of the dorsal capsule and synovium, and debridement of dorsal osteophytes to minimize the risk of recurrence.
• An H-shaped incision with the transverse limb over the DIP joint and the longitudinal
limbs in the midaxillary line
• In an open draining sinus, a rotational flap is done by triangulating the cyst into the incision.

Curettage and bone grafting is done for established ganglion cyst of bone.

Complications:
• Recurrence
• Painful neuroma if the superficial branch of the radial nerve or palmar cutaneous branch of the median nerve is involved
• Intercarpal instability if the intercarpal ligaments are accidentally excised
• Injury to radial artery in the volar radial wrist, ulnar neurovascular injury in the ulnar volar wrist, and digital neurovascular injury in the region of the palmar digital crease.

NB: Turret exostosis – Traumatic subperiosteal haemorrhage in the phalangeal bones that leads to extraperiosteal new bone formation. Excision after the bone matures is curative.

The inspiring story of GERHARD KUNTSCHER

GERHARD KUNTSCHER (1900-1972)



- Served in the German army during the Second World War.
- Kuntscher was prejudiced academically and ‘was never offered a chair’.
- Developed the Kuntscher nail for the treatment of femur fractures
- The first intramedullary nailing was performed in 1939 University of Hamburg’s Department of Surgery
- German military initially disapproved of Kuntscher’s IM nailing technique
- The German military had the upper hand on treating soldiers with the IM nail and having them return to fighting status in just a few weeks.
- Worldwide knowledge was not established until the Prisoners of War (POW’s) returned to their home countries carrying Kuntscher’s legacy in the form of steel nails in their legs
- 'The war and the post-war period' produced unfavorable conditions that severely limited and hampered his creative activities


- Küntscher published his first book on intramedullary nailing at the end of World War II.
- Although it was written in 1942, the illustrations for it were destroyed in the air raids on Leipzig, so the book was not published until 1945.
- In 1945, the Germans understood Kuntscher's technique when the book was published.
- Küntscher developed femoral and tibial nails, an intramedullary bone saw for endosteal osteotomy, the distractor to align the fractures, an expanding nail for the distal tibia, the “signal arm” nail for Trochanteric fractures, cannulated flexible powered intramedullary reamers, and an intramedullary nail to apply compression across fracture sites.
- All this was done in collaboration with his engineer, Ernst Pohl, and his lifetime technical assistant, Gerhardt Breske.
- Of Küntscher's invention, A. W. Fischer said in 1944: "This practical treatment of fractures using a nail, the Küntscher procedure, is, in my eyes, a great revolution that will conquer the world."

- Küntscher was a great lover of life: he swam every day; he enjoyed humor and parties and was a great practical joker, but never married, according to Herr Breske, because “he was far too busy.”
- Unfortunately, only in his very late years did Küntscher’s accomplishments and work earn widespread recognition and respect. ‘It disappointed him that his operative methods were regarded sceptically at first.’
- Gerhardt Küntscher died in 1972 at his desk, ‘working on yet a further edition of his book on intramedullary nailing’.
- He was found slumped over his final manuscript on “Practice of Medullary Nailing” by Dr. Wolfgang Wolfers, chief of surgery at the St. Franziskus Hospital of Flensberg, where from 1965 onward Küntscher had worked as a guest surgeon

Ref:
1. M S. and Siegfried Fischer et al..Gerhard küntscher 1900-1972 J Bone Joint Surg Am. 1974; 56:208-209.
2. Seyed Behrooz Mostofi in 'Who's who in Orthopaedics', 2005, Springer verlag, United States of America

Musculoskeletal Manifestations of HIV infection

MUSCULOSKELTAL MANIFESTATIONS OF HIV INFECTION

• The etiologic agent of AIDS is HIV, which belongs to the family of human retroviruses (Retroviridae) and the subfamily of lentiviruses
• The most common signs and symptoms are fever, fatigue, and a maculopapular skin rash and seen in 90 % patients with acute infection
• Around 50% to 70% also complain of myalgias, arthralgias, and paresthesias, which may be the only symptoms of the acute infection.
• Acute HIV infection should be included in the differential diagnosis of sudden onset of arthralgias and myalgias with a compatible history of exposure.





Myopathies
a) Pyomyositis :maybe misdiagnosed as muscle strain, contusion, hematoma, cellulitis, deep vein thrombosis, osteomyelitis, septic arthritis, or neoplasm
• Staphylococcus aureus is the most common pathogen (90% of cases) but Streptococcus pyogenes, Mycobacterium tuberculosis, Nocardia asteroides, and Cryptococcus neoformans is also found.
• Pyomyositis develops in patients with preexisting muscle damage who experience transient bacteremia.
• Muscle injury maybe due to nutritional deficiencies, azidothymidine (AZT)-induced mitochondrial injury, opportunistic infections, or direct viral invasion of muscle tissue in HIV-infected patients.
• Aggressive management with i.v antibiotics and surgical drainage should be done.

b) Polymyositis:
- bilateral, symmetrical proximal muscle weakness associated with elevated
serum CK levels.
• Cause: direct muscle injury by the virus or immunogenic reaction
• MRI, EMG or muscle biopsy will confirm the diagnosis.
• In MRI, Unlike pyomyositis, rim enhancement is not present
• NSAIDs, oral prednisolone(upto 60mg/day)

c) AZT Myopathy• Reversible toxic mitochondrial myopathy that mimics polymyositis clinically.
• Patients usually present with myalgia, fatigue, proximal muscle weakness, and elevated serum CK levels.
• EMG shows myopathy
• Treatment is withdrawal of AZT and institution of another antiviral agent.

Infections

a) Tuberculous Osteomyelitis
• Commonly affects the spine
• The thoracic and lumbar (especially L1) regions are most commonly affected;
• Infection usually begins in the vertebral body and spreads to adjacent disc.
• The duration of antibiotic tuberculosis therapy usually is longer in HIV-infected patients(1 year)

b) Bacillary Angiomatosis
• Caused by bartonella henselae(formerly Rochalimaea henselae)
• Cat bite and cat scratch are strong risk factors.
• Multiorgan involvement may include adenitis, intracerebral mass lesions, aseptic meningitis, peliosis hepatis, and osteomyelitis.
• Cutaneous lesions are characterised by friable angiomatous papules, which resemble Kaposi’s sarcoma lesions.
• The presence of osseous lesions, which are not typically seen with Kaposi’s sarcoma, may help differentiate this disease
• Osseous lesions are lytic and can be associated with periostitis and a soft-tissue mass
• Extensive cortical damage and medullary permeation are seen, often preceding the cutaneous lesions by many months.
• The overlying skin changes mimic cellulitis.
• Increased uptake on technetium 99m bone scan; MRI shows the nonspecific changes of osteomyelitis.
• Warthin- Starry silver staining is used to identify the bacillary organism.
• Early treatment with erythromycin should be instituted when an osteolytic lesion in present

Neoplasms

a) Non-Hodgkin’s Lymphoma
• It is the second most common type of tumor in HIV-infected persons after Kaposi’s sarcoma
• Extranodal involvement, including the central nervous system, bone marrow, abdominal organs, and mucocutaneous sites, is common
• Patients may present with pain, fever, weight loss and pathologic fracture.
• On X-rays it is commonly osteolytic with cortical destruction and permeation. Sclerotic and mixed appearance may also be seen. DD includes osteomyelitis
• Treatment is by chemotherapy, radiotherapy and surgical debulking in selected patients

b) Kaposi’s sarcoma
• Is seen in 20% of patients with HIV
• Osseous lesions range from erosions to discrete osteopenia or cortical destruction
• Treatment consists of chemotherapy and radiation

Inflammatory arthropathy

a) Reiter’s syndrome
• Is 100 to 200 times more frequent in the HIV infected population than in the noninfected.
• Commonly oligoarticular, predominantly involving the lower extremities.
• Enthesopathy is common, which frequently involves the Achilles tendon, plantar fascia, and extensor tendons, as well as anterior and posterior tibial tendons.
– This is called AIDS foot and presents as a broad-based gait with weight bearing through the lateral margins of the feet to protect the painful heel.
• It can be extremely disabling, some patients become wheelchair bound, and may mimic a peripheral neuropathy.
• Upper extremity enthesopathy may include medial or lateral epicondylitis, rotator cuff tendinitis, de Quervain’s tenosynovitis, or flexor tendinitis.
• Associated with HLA- B27
• Is usually refractory to treatment with NSAIDs, but possibly responds to second line drugs like phenyl butazone and sulphasalazine
• Cyclosporine and prednisone may be used in refractory cases
• But methotrexate is contraindicated since it may precipitate full blown AIDS and Kaposi’s sarcoma

b. Psoriatic Arthritis
• Typical cutaneous manifestations include circumscribed, discrete, and confluent red, silvery scaled maculopapules that occur predominantly on the elbow, knee, scalp, and trunk.
• Treatment is similar to Reiter’s syndrome

c. HIV associated arthritis
- Usually involves the knees and ankle
- X-rays show non specific changes
- Synovial biopsy shows a chronic process with a predominantly mononuclear
cell infiltrate.
- Rheumatoid factor and HLA B 27 are characteristically negative
- Treatment is by administering intra articular steroid injections

d. Painful articular syndrome
• The hallmark of this arthritis is a sharp, severe arthralgia of acute onset that often simulates a septic joint
• MC site: knee> elbow> shoulder
• Differentiated from a septic joint by its intermittent pain pattern and lack of effusion or synovitis on physical examination.
• X-rays are non specific
• This self-limited condition lasts from 2 to 24 hours and responds well to narcotics and anti-inflammatory medications.

e. Acute symmetric polyarthritis
. is unique to HIV-infected patients and resembles rheumatoid arthritis both clinically and radiographically
• Rheumatoid factor is usually negative
• Gold is used for treatment

f. Hypertrophic Osteo arthropathy:
- Severe pain in the lower extremity is typical, and
clinical manifestations include arthralgias, nonpitting edema, digital clubbing, and periarticular soft-tissue involvement of the ankle, knee, and elbow
• Extensive periosteal reaction and subperiosteal proliferative changes of the long bones
• Surgical or chemical vagotomy or radiation therapy has been used to relieve bone pain in refractory cases

g. Osteonecrosis:
• Embolic phenomena secondary to the formation of antiphospholipid antibodies and immune complexes, protein S deficiency, and hypergammaglobulinemia also have been proposed as etiologies
• There is a strong correlation between protease inhibitor use and osteonecrosis of the femoral head.

Ref:
1. Rodgers WB, Yodlowski ML, Mintzer CM: Pyomyositis in patients who have the human immunodeficiency virus: Case report and review of the literature. J Bone Joint Surg Am 1993;75:588-592.
2. Luck JV Jr, Logan LR, Benson DR, Glasser DB: Human immunodeficiency virus infection: Complications and outcome of orthopaedic surgery. J Am Acad Orthop Surg 1996;4:297-304.
3. Paiement GD, Hymes RA, LaDouceur MS, Gosselin RA, Green HD: Postoperative infections in asymptomatic HIV-seropositive orthopedic trauma patients. J Trauma 1994;37:545-551.
4. Ragni MV, Crossett LS, Herndon JH: Postoperative infection following orthopaedic surgery in human immunodeficiency virus-infected hemophiliacs with CD4 counts < or = 200/mm3. J Arthroplasty 1995;10:716-721.
5. Ayaz A. Biviji,, Guy D. Paiement, Lynne S. Steinbach : ‘Musculoskeletal Manifestations of Human Immunodeficiency Virus Infection’ J Am Acad Orthop Surg 2002;10:312-320

Calcaneal Fractures

CALCANEUM fractures
Mechanism of Injury: fall from height or motor vehicle accident

Classification:
a. Extra Articular Fractures
• Anterior process fractures
• Tuberosity fractures
• Medial process fractures
• Sustentacular fractures
• Body fractures not involving the subtalar articulation

b. Intra Articular Fractures (Essex Lopresti Classification)
Intra- articular fractures involve the subtalar joint.

They have primary and secondary fracture lines. Intra articular fractures are more common (75%)

Primary Fracture Line Producing two main fragments:
 Sustentacular (anteromedial) and the tuberosity (posterolateral) fragments.
 The anteromedial sustentacular fragment is also called the ‘constant fragment‘ because of its resistance to significant displacements.
 The anteromedial fragment consists of part of the posterior facet, anterior process, middle and anterior facets, supported by the sustentaculum tali.
 The posterolateral fragment consists of the tuberosity and lateral wall along with a variable portion of the posterior facet.

Secondary Fracture Line
• Tongue fracture. Secondary fracture line appears beneath the facet and exits posteriorly. The relationship of the lateral posterior facet and the superior aspect of the tuberosity remain intact.

• Joint depression fracture: Secondary fracture line exits just behind the posterior facet. Joint depression fractures are those in which the secondary fracture line separates the lateral posterior facet from the body and tuberosity of the calcaneus.

Sanders Classification
Describes comminution and displacement of the posterior facet by computed tomography.
CT scan is essential if surgical treatment is being planned.

• Type I: All Nondisplaced fractures regardless of the number of fracture lines
• Type II: Two-part fractures of the posterior facet; subtypes IIA, IIB, IIC based on the location of the primary fracture line
• Type III: Three-part fractures in which a centrally depressed fragment exists; subtypes IIIAB, IIIAC, IIIBC
• Type IV: Four-part articular fractures; highly comminuted

 Bohler’s tuber joint angle :( 25 to 40 degree normal). Decreased in intra-articular calcaneal fractures.

 Crucial angle of Gissane: Angle formed between the posterior facet and the anterior facet. Normal angle is 110 to 130°. Increased in intra-articular calcaneal fractures.



 Harris axial view is used to assess varus or Valgus position and width of the heel.

 Brodén view, obtained by internally rotating the leg 40 degrees with the ankle in neutral, then angling the beam 10 to 15 degrees cephalad, helps to evaluate congruency of the posterior facet

Treatment
• Extra-articular fractures of the calcaneum can be treated conservatively.
Displaced tuberosity avulsion fracture, which serves as the attachment of the tendo calcaneus should be internally fixed with a screw to restore the power of the tendo calcaneus and prevent a wide heel with the ensuing difficulties of shoe-fitting
• Intra-articular fractures:
‣ Should be treated with ORIF with plates and screws (Reconstruction plate) in order to reconstruct the articular surface.
‣ Axial fixation using the Gissane spike has been popularized by Essex Lopressti

‣ Patients with increasing physiological age, male gender, tobacco use, a pending worker’s compensation claim, heavy laborers, bilateral injuries and increasing comminution of posterior facet may not have significant improvement in function with surgery as compared to nonsurgical treatment(1,2)

‣ Anatomic surgical reduction of posterior facet results in improved outcomes compared with those achieved reduction with residual steps, gaps or comminution.

Surgical Pearls:
• Reconstruction of the calcaneus:
 Surgical reconstruction maybe delayed for 7 to 10 days for optimization of soft tissue status
 Performed through a lateral “L” incision, with the vertical limb just posterior to the midpoint between lateral border of Achilles tendon and posterior aspect of fibula, posterior to sural nerve.
 The lateral border of the calcaneus is exposed subperiosteally by elevating a full thickness flap. Peroneal tendons, sural nerve and calcaneofibular ligament are reflected en masse in the flap.
 Vascularity of flap is based on peroneal artery blood supply which remains protected within substance of flap
 Reduction typically proceeds from anteromedial to posterolateral, effectively decompressing central portion of calcaneus to allow accurate reduction of posterior facet fragments
 A pin is placed in the posterior fragment to improve exposure of the fracture and to facilitate reduction.
 A plate (reconstruction plates, precontoured periarticular multiple limbed plates or LCP) is placed laterally after the fracture has been reduced, and fixation is provided by placing screws into a stable fragment, commonly the sustentaculum tali.
 Principles of reconstruction include restoration of calcaneal height (Bohler’s angle), heel width (as in axial view), posterior facet alignment, and anatomic realignment of the three superior facets to each other.
 The sural nerve is preserved and the peroneal tendons reflected ‘en masse’ to expose the sub-talar joint.
 Large Bony defects may require bone grafting.
 The incision is closed primarily, using a two layered closure. There should be a deep interrupted absorbable periosteal suture followed by a separate nylon modified Allgower-Donati flap stitch to minimise tension along the skin incision.
 posterior splint is applied

Complications of Calcaneal Fractures:
• Wound Necrosis, Dehiscence, and Infection: Carefully retracting the soft tissues and maintaining a full-thickness flap during open reduction are crucial.
• Lateral fibular impingement: This is treated by lateral decompres¬sion.
• Post traumatic arthrosis of subtalar joint: Treated by subtalar arthrodesis.

Open calcaneal fractures:
• 5- 10% calcaneal fractures are open
• Most of the wounds occur in the medial aspect of foot
• They are prone for wound complications like osteomyelitis, poor functional outcome and amputation
• Gustilo I and II open fractures on medial side can be treated with ORIF with results similar to closed fracture.
• With more extensive soft tissue compromise or type II non medial wounds, external fixation and/or percutaneous screw fixation should be considered.
• Alternative treatment methods for open calcaneal fractures like percutaneous limited approaches, arthroscopy assisted techniques and ring fixators.


Further Reading:
1. Buckley RE, Tough S. Displaced intra-articular calcaneal fractures. J Am Acad Orthop Surg 2004;12:172–178
2. Buckley R, Tough S, McCormack R et al.. Operative compared with nonoperative management of displaced intraarticular fractures. A prospective RCT. JBJS 2003;84-A, 1733-1744

TIBIA VARA (BLOUNT DISEASE)

TIBIA VARA (BLOUNT DISEASE)

Classification:
- Infantile form: Presents in children 0–4 years old
 Juvenile form: Presents at >4–9 years of age in obese children
 Adolescent form: Presents in children >10 years old; has excellent prognosis with surgery

Aetiology:
• Abnormal compression on the posteromedial aspect of the proximal tibial physis, causing retardation of growth from that area
• Or increased growth from the proximal aspect of the fibula and the lateral aspect of the proximal part of the tibia, or both.
• This multiplanar deformity consists of varus, procurvatum and internal tibial torsion.
• Additionally, distal femoral varus is commonly noted in the late-onset form.
• Blount’s disease is the most common cause of pathologic genu varum
• The Hueter Volkmann law probably explains the aetiology: Compressive forces inhibit bone growth and tensile forces stimulate bone growth at physis.

NB: Normal knee alignment progresses from 10 to 15 degrees of varus at birth to a maximum or peak valgus angulation of 10 to 15 degrees at the age of three to three and half years. Neutral femorotibial alignment is achieved when child is 14 months to 20 months old

Risk factors:• African American ethnicity
• Obesity
• Early age of walking
• Varus greater on the tibial than the femoral side is a risk factor for infantile and juvenile Blount disease

Clinical features:• Generally present at fourteen to thirty-six months old for evaluation of bowlegs.
• Infantile tibia vara is found more frequently in children who are black, female, and obese and who started walking at an early age
• The infantile form is more common in girls.
• The juvenile or adolescent form is more common in boys.
• Progression to severe form is more common in infantile variety compared to juvenile and adolescent forms
• The finding of short stature suggests rickets or a skeletal dysplasia

Differential diagnosis:
• Physiological bowlegs
1. The most common cause of genu varum in this age group.
2. Their bowlegs will spontaneously resolve before the age of three.

• Hypophosphatemic rickets:
1. Short stature and genu varum are features.
2. X-rays show widening or rachitic-like changes at the physis.
3. Serum Phosphorus is low
• Metaphyseal chondrodysplasia,
• Focal fibrocartilaginous dysplasia.



Langenskold Classification
• Stage I: Irregularity of medial proximal tibial physis with varus deformity.
• Stage II: Medial tapering of epiphysis, metaphysis and slight step in the physis.
• Stage III: Sharp angular step in the medial proximal tibial metaphysis.
• Stage IV: Ossification of epiphysis into the metaphyseal step.
• Stage V: Appearance of separate medial fragment.
• Stage VI: Bony bridge formation.




This is still the most commonly employed classification system though significant interoberver variability is seen in the intermediate stages.

X-ray
• A standing full-length anteroposterior radiograph (teleoroentgenogram) of the entire length of both lower extremities with the patellae forward is crucial for a detailed analysis of frontal plane alignment
• To obtain a true AP view: no more than 60% of the proximal part of the fibula should be seen to overlap the adjacent tibia on a true anteroposterior radiograph centered at the knee, irrespective of the patient’s age


• Drennan’s metaphyseal-diaphyseal angle of more than 11 degrees warrants close observation
>16 degree: Diagnostic
• The medial physeal slope: an angle formed by the intersection of a line through the lateral aspect of the tibial physis and a line through the medial aspect of the physis
.
• The medial physeal slope is a better radiographic predictor of recurrent varus deformity following osteotomy.
• A medial physeal slope greater than 60 degrees is always associated with recurrent varus deformity after tibial osteotomy

CT scan:
 Can be useful in delineating the physeal damage that later may form a bar
 A physeal bar is not common in adolescent variety, but the deformity maybe present in both the femur and tibia

3-D CT scan: helpful for preoperative planning in children with early-onset Blount disease who present with recurrent deformities

An intraoperative arthrogram is helpful for delineating the articular surface and for evaluating dynamic instability of the knee

MRI to define intra-articular changes such as posteromedial depression of the tibial plateau and hypertrophy of the medial meniscus in children with early-onset disease
• detecting growth plate irregularities and early physeal bar formation

Treatment• Lower stages:
 Brace (KAFO) with a medial upright and droplock hinges to unload the medial compartment of the knee for children younger than thirty-six months of age with early-stage(Langenski¨old stage-I or II) Blount disease
 Full-time bracing (22 hours a day) puts a corrective valgus stress on the knee (more knock-kneed) and decreases the stress on the medial physis
 Risk factors for failure of brace treatment include: a weight greater than the 90th percentile, varus thrust and bilateral disease
• Proximal tibial valgus osteotomy may be done if patient presents between 3 and 4 years of age and stage III or IV:
 10 degree overcorrection is recommended.
 Elevation of depressed tibial plateau must be done.
 Chemoprophylaxis with LMW Heparin maybe given if children are obese
• Stage V, VI: Excision of bar and insertion of free fat graft. An osteotomy often is combined with completion of the closure of the proximal tibial physis. Lengthening maybe performed later.
• Adolescent form: Osteotomy may be combined with hemiepiphysiodesis on the lateral side, and later lengthening of necessary

Tumour Biopsy Principles

PRINCIPLES OF TUMOUR BIOPSY:

1. Biopsy should be done only after clinical, laboratory, and roentgenographic examinations are complete. This will help in planning the placement of the biopsy incision. It will also help to make an accurate diagnosis
2. Place small incisions whenever possible, also use small capsular incisions over the tumour thus reducing bleeding
3. The biopsy track should be considered contaminated with tumor cells. Placement of the biopsy incision therefore is important because the biopsy track should also be excised en bloc with the tumor subsequently.
4. The surgeon should be familiar with incisions for limb salvage surgery, and also with standard and nonstandard amputation flaps.
5. If a tourniquet is used, the limb is elevated before inflation but should not be exsanguinated by compression because the latter may cause tumour spread.
6. Care should be taken to contaminate as little tissue as possible. Transverse incisions should be avoided since they are extremely difficult or impossible to excise with the specimen. The deep incision should go through a single muscle compartment (muscle belly) rather than through an intermuscular plane. Major neurovascular structures should be avoided. Care should be taken not to contaminate flaps. Minimal retraction should be utilized to limit soft tissue contamination.
7. If possible soft tissue extension of a bone lesion should be sampled
8. If a hole must be made in the bone, it should be round or longitudinally oval to minimize stress concentration and prevent a subsequent fracture. A fracture may preclude a subsequent limb salvage surgery. PMMA is plugged into the hole to contain a hematoma. Only minimal amount of PMMA needed to plug the hole should be used because excessive amounts will push the tumor up and down the bone.
9. Biopsy should be taken from the periphery of the lesion, which contains the most viable tissue. Biopsy material may be sent for culture and sensitivity if there is a doubt regarding infection
10. A frozen section should be sent intraoperatively to ensure that diagnostic tissue has been obtained. If a tourniquet has been used it should be deflated and meticulous haemostasis ensured before closure, since a hematoma would be contaminated with tumor cells.
11. Drains should not be used routinely. If a drain is used, it should exit in line with the incision so that the drain track also can be easily excised en bloc with the tumor. The wound should be closed tightly in layers.
12. When performing an open biopsy the operating surgeon should accompany the specimen to the pathologist if feasible and should discuss with the pathologist about clinical findings, imaging, intraoperative findings and the specimen.

Ref:
1. Mankin HJ, Mankin CJ, Simon MA: The hazards of the biopsy, revisited. Members of the Musculoskeletal Tumor Society. J Bone Joint Surg 1996; 78A:656.


IMMUNOHISTOCHEMISTRY:

 Immunohistochemical stains are used to identify certain specific intermediate filament proteins like desmin, vimentin, keratins, neurofilament, glial, fibrillary and lamin filament proteins.
 These can be appreciated in light microscopy after appropriate staining of the biopsy tissue
 Certain tumours have specific Immunohistochemical profiles that help in their identification
 Keratins (epithelial origin) are classically found in metastatic carcinomas. They are also seen in tumours containing epithelial elements like adamantinoma, synovial sarcoma, and epithelioid sarcoma.
 Vimentin (mesothelial origin) is positive in all sarcomas but occasionally negative in carcinomas
 Desmin and actin (muscle origin) is positive in tumours with myodifferentiation like rhabdomyomas, Rhabdomyosarcoma, leiomyomas and leiomyosarcomas. May also be present in desmoid tumours and primitive neuroectodermal tumours
 S- 100: the name of this protein is derived from the fact that it is soluble in 100% ammonium sulfate. It is positive in Histiocytosis-X
 Factor VIII related antigen (von Willebrand’s factor): these are positive in low-grade vascular lesion like hemangiomas and hemangioendotheliomas. But negative in high grade angiosarcomas

FIBROUS DYSPLASIA

Fibrous Dysplasia

• originally described by Lichtenstein in 1938 and by Lichtenstein and Jaffe in 1942
• represent approximately 5% to 7% of benign bone tumors
• A sporadic disorder of osseous and fibrous tissue development characterised by postzygotic mutation of GNAS1 gene coding for stimulatory G protein.
• Analysis of the Gs α subunit in patients with fibrous dysplasia, as well as in those with McCune-Albright syndrome, reveals a missense point mutation at the arginine 201 codon, which results in an arginine-to-histidine or arginine-to-cysteine substitution in the end protein product
• This result in autonomous function in bone, skin and various endocrine glands dependent on c-AMP -protein kinase, a signal transduction pathway.
• It is postulated that elevated levels of cAMP could then lead to the expression of proto-onco genes such as c-fos in affected osteoblasts.
• The proto-onco gene c-fos has been implicated in the process of osteoblastic differentiation and proliferation that may lead to the formation of fibrous dysplasia lesions
• In bones areas of trabecular origin, bone is replaced by cellular fibrous tissue containing flecks of osteoid and woven bone.
• Tumour progression occurs during pregnancy indicating the presence of oestrogen receptors
• It can be monostotic, polyostotic or monomelic.
• McCune-Albright syndrome-polyostotic fibrous dysplasia plus café-au-lait spots (Coast of Maine appearance) and hyperfunction of endocrine systems like precocious puberty.
• Mazabraud’s syndrome: in this syndrome skeletal lesions of fibrous dysplasia are combined with intramuscular myxomas.

Clinical features:

• Pain and deformity are signs that microfractures are developing in a lesion and should be
addressed.
• Localized pain may be the presenting symptom in patients with fatigue fractures in high-stress areas in dysplastic bone, especially in the femoral neck.
• Can occur at any age but mostly seen around the age of 30.
• Female patients can experience an increase in the pain level during pregnancy and at
particular times during their menstrual cycle because of estrogen receptor
• Polyostotic form involves maxilla and other craniofacial bones, ribs, metaphyseal or diaphyseal portions of proximal femur and tibia (MC site: proximal femur).
• Weight bearing bones may be deformed, e.g. shepherd’s crook deformity of proximal femur.
• Pathological fractures may occur and are more frequently seen in polyostotic disease
• Sarcomatous degeneration (osteosarcoma) of femur or facial bone is a rare complication.
• Rarely renal wasting of phosphate leading onto rickets coexists.
• In McCune Albright syndrome the lesion tend to be larger, more persistent, and associated with more complications
• Polyostotic disease may have deformities, which include: coxa vara, the shepherd’s crook deformity, bowing of the tibia, the Harrison groove (a horizontal depression along the lower border of the thorax, corresponding to the costal insertion of the diaphragm), and protrusio acetabuli
• Malignant transformation is seen in 0.4 to 4 % of tumors and includes osteosarcoma, fibrosarcoma, and chondrosarcoma.(3)
• Malignant transformation is seen in adults over 30 years of age and the most common site of involvement is the craniofacial area, followed by femur, tibia and pelvis and also tends to occur more frequently in Mazabraud’s syndrome(1,2).

Gross pathology:• Yellowish white tissue with a distinctive gritty feel, imparted by the small trabeculae of bone scattered throughout the lesion
• The lesion can be easily peeled away from the encircling shell of reactive bone by blunt dissection
• The tissue can be cut with a scalpel and may bleed briskly when cut, as a result of its concentration of small vessels.
Histology: there is fibroblast proliferation that produces collagen matrix along with metaplastic woven bone. The woven trabeculae are disorganized and have been described as having a ‘Chinese letter’ appearance. Areas of cartilage formation are commonly present

X-ray:
• Radiolucent cystic areas, which are expansile with deep endosteal scalloping and ‘ground glass appearance’ or ‘shower door glass appearance’ in the metaphysis or shaft with medullary calcification.
• Lesion is bounded by a distinct rim or shell of reactive bone that is defined more sharply on its inner border than on its outer border, where it may fade gradually into normal cancellous bone
• Can grow eccentrically or concentrically and can resemble simple bone cyst.
• Endosteal scalloping maybe present, the periosteal surface is smooth and without reaction.
• Monostotic lesions mature after skeletal growth ceases., whereas polyostotic lesions continue to grow
• A well-defined sclerotic rim is usually seen.
• Radiologically facial bone involvement present as radiodense lesions (leonine ossea- leonine appearance)
• When a fatigue fracture is present in the proximal femur there are two humps of reactive bone on the medial cortex separated by a thin radiolucent line resembling a “parrot’s beak”

Bone scans are useful to evaluate the extent of the disease. A bone scan that does not show increased uptake does not exclude the diagnosis of fibrous dysplasia

CT scans are useful to evaluate the thickness and extent of lesion, also endosteal reaction, periosteal new bone reaction, and homogeneity of the poorly mineralized lesional tissue

MRI:• T1-images show low signal intensity, T2-weighted images have a higher-intensity signal
that is not as bright as the signal of malignant tissue, fat, or fluid.
• Cysts demonstrate high signal intensity on T2-weighted images secondary to high water content.
• It is also useful in evaluating suspected malignant degeneration of known fibrous dysplasia lesions by showing the extent of the lesion and/or the surrounding soft tissues and its soft-tissue extension, if present.

Treatment
No effective treatment is available.
1. Monostotic asymptomatic small lesions require no surgery especially in patients who have attained skeletal maturity. In newly identified cases, a bone scan is needed to exclude a diagnosis of polyostotic disease. When polyostotic disease is found, a referral to an endocrinologist for endocrine and metabolic testing is paramount
2. I.v pamidronate therapy may cause radiographic resolution in polyostotic disease (4). Dose:
60mg/day for 3 days, which is repeated every 6 months, supplemented with calcium (500 to 1500 mg/day) and vitamin D (800 to 1200 IU/ day).
Monitoring markers of bone turnover (N-telopeptide and alkaline phosphatase) at six-month intervals and bone mineral density yearly during treatment is a means of assessing the efficacy of bisphosphonate therapy.
3. Large painful, fracture prone lesions can be curetted and grafted. A cortical graft may be useful to bridge the defect, especially a cortical allograft since it is reabsorbed slowly.
– Suitable osteotomies to correct deformities may be employed.
– Treatment may be postponed until skeletal maturity since recurrence is very common
– Fixed-angled internal-fixation devices, like intramedullary nails should be employed to correct the deformity.
– Collins et al devised an insturment for measuring the skeletal burden of fibrous dysplasia and predicting the functional outcome (5). Decision and type of surgery can be attained from this score.
– Irradiation is contraindicated because of the risk of radiation induced sarcoma later in life

Ref:
1. Yabut SM Jr, Kenan S, Sissons HA, Lewis MM. Malignant transformation of fibrous
dysplasia. A case report and review of the literature. Clin Orthop Relat Res.
1988;228:281-9.
2. Lopez-Ben R, Pitt MJ, Jaffe KA, Siegal GP. Osteosarcoma in a patient with Mc-Cune-Albright syndrome and Mazabraud’s syndrome. Skeletal Radiol. 1999;28:522-6.
3. Harris WH, Dudley HR Jr, Barry RJ. The natural history of fibrous dysplasia. An orthopaedic, pathological, and roentgenographic study. Am J Orthop. 1962; 44:207-33.
4. Chapurlat RD, Delmas PD, Liens D, Meunier PJ. Long-term effects of intravenous pamidronate in fibrous dysplasia of bone. J Bone Miner Res. 1997;12:1746-52.
5. Collins MT, Kushner H, Reynolds JC, Chebli C, Kelly MH, Gupta A, Brillante B, Leet AI, Riminucci M, Robey PG, Bianco P, Wientroub S, Chen CC. An instrument to measure skeletal burden and predict functional outcome in fibrous dysplasia
of bone. J Bone Miner Res. 2005;20:219-26.

Stem cells in Orthopaedic Surgery

STEM CELLS IN ORTHOPAEDIC SURGERY


 A stem cell is an ‘immature’ or undifferentiated cell which is capable of producing an identical daughter cell.
 Stem cells must have a capacity for self-renewal giving rise to more stem cells, and the ability to differentiate into tissues of various lineages under appropriate conditions

 They may be totipotent, pluripotent or multipotent, depending on type

 Totipotent: Cells which can form all the cells and tissues that contribute to the formation of an organism

 Embryonic stem cells (ESCs) are pluripotent, which can form most, but not all cells or tissues of an organism

 Differentiation of adult stem cells is generally restricted to the tissue in which they reside. Under appropriate conditions some can differentiate into multilineages, becoming multipotent. Eg., mesenchymal stem cells (MSCs) which are found in bone marrow, skin, adipose tissue

 These cells are capable of differentiating into bone, cartilage, tendon, ligament, fat and other tissues of mesenchymal origin

 The phenomenon of transdifferentiation: Here cells from one lineage dedifferentiate, giving rise to an intermediate cell type, before redifferentiating into cells of another lineage
 MSCs as progenitor cells, injected directly into tissues to enhance the process of repair, or by using them as a vehicle for gene delivery.
 Articular cartilage is vulnerable to injury and has poor potential for repair

 Procedures directed at the recruitment of stem cells from the marrow by penetration of the subchondral bone have been widely used to treat localised cartilage defects (autologous chondrocyte implantation)

 Attempts to 'regenerate' normal articular cartilage have been introduced in clinical practice with autologous chondrocyte implantation. Lesions of osteochondritis dissecans or traumatic osteochondritis can be treated with this technique

Bone

 Trauma and some pathological conditions may lead to extensive loss of bone, which requires transplantation of bone tissue
 Mesenchymal stem cells derived from bone marrow have been used to treat segmental bone defects (Quarto et al)

 Successful tissue engineering of bone requires osteoproduction, osteoinduction, Osteoconduction and mechanical stimulation

 Bone induction to assist and enhance bone deposition and repair was introduced by Urist in 1965 and led to the isolation of the BMPs, which could stimulate osteogenic precursor MSCs to form bone.

 A number of studies have shown the potential for BMP-2, BMP-3 and BMP-4 in the healing of fractures and segmental bone defects, and in the fixation of prosthetic implants

 BMP regulates chemotaxis, mitosis and differentiation, and is fundamental in initiating fracture repair

 TGF-β and IGF may stimulate fracture repair and minimise the rate of nonunion

 In order for BMP to induce bone formation effectively, its dose must be of sufficient concentration for a sustained period.

 However, these proteins have short biological half-lives and must be maintained at therapeutic concentrations at the fracture site to be effective

Tendons and ligaments

 In rabbits tendoachilles tears and patellar tendon defects have been successfully been treated by MSC.( Young et al)
 Key to success in surgical reconstruction of the anterior cruciate ligament (ACI.) is the healing of the tendon graft to the bone.
 The normal anatomy of the insertion site of the ACL is fibrocartilaginous and consists of four distinct zones: ligament substance, unmineralised fibrocartilage, mineralised fibrocartilage and bone

 Conventional free tendon transfers are unable to restore this complex anatomy within the first six months

 By applying MSCs to tendon grafts at the tendon-bone junction results in a zone of fibrocartilage at the junction which more closely resembled that of the normal ACL (Lim et al)

Meniscus

 Tears in the avascular inner third of the meniscus have limited or no potential for repair as the reparative process cannot occur without the presence of bleeding
 Dutton et al assessed the capability of autologous seeded BMSCs to repair an avascular meniscal lesion in the pig.
 They showed that a meniscal lesion involving the inner, avascular, one-third of the meniscus benefited from the bonding capabilities of the transplant.
 This study raises the potential of cell-based therapy to repair a tear in the avascular inner third of the meniscus rather than proceeding to surgical resection.

Spine
 Degeneration of the intervertebral disc is a leading cause of back pain and morbidity
 Most commonly, fusion with or without discectomy is performed, although more recently disc replacement has received some attention
 Cell transplantation can potentially increase proteoglycan production, induce disc regeneration or slow the process of degeneration (Crevenstcn et al)
 Spinal fusion: a novel approach to create a hybrid graft by combining cultured MSCs with a ceramic scaffold (Cinotti et al)
Spinal cord
 Stem cell therapy has therapeutic potential for spinal cord injuries because of the ability of pluripotent cells to differentiate into neural tissue
 But, repair of the spinal cord is very complex. It includes restoring or enhancing local spinal reflex arcs and reconnecting regenerating axons from above.
 Gliosis may block the outgrowth of axons
 MSCs isolated in culture from the mononuclear layer of bone marrow can remyelinate demyelinated spinal cord axons after direct injection into the lesion (Akiyama et al)

Paediatric Orthopaedics
- Deformity correction in children sometimes include excision of a preexisting bony bridge and the insertion of fat, polymeric silicone or muscle as an interpositional material
 Cultured chondrocytes have been transferred into physeal defects for the correction of established growth arrest in animal models
 Attention has turned to the use of MSCs from bone marrow to repair physeal defects
 Duchenne’s Muscular dystrophy: An encouraging and pioneering experiment in mouse models of DMD demonstrated that myoblasts could be transplanted into dystrophic muscle and repaired a small proportion of damaged myofibres
 Other diseases where stem cells are being tried are Osteogenesis imperfecta and Juvenile rheumatoid arthritis.

Ref:
1. Urist MR. Bone formation by autoinduction. Science 1965;150:893-9.
2. Young RG, Butler DL, Weber W, et al. Use of mesenchymal stem cells in a collagen matrix for Achilles tendon repair. J Orthop Res 1998;16:406-13.
3. Lim JK. Hui J, Li L, et al. Enhancement of tendon graft osteointegration using mesenchymal stem cells in a rabbit model of anterior cruciate ligament reconstruction. Arthroscopy 2004;20:899-910
4. Dutton A, Hui JPP, Lee EH, Goh J. Enhancement of meniscal repair using mesenchymal stem cells in a porcine model. Procs 5th Combined Meeting of the Orthopaedic Research Societies of USA, Canada, Japan & Europe. 2004
5. Crevensten G, Walsh AJ, Ananthakrishnan D, et al. Intervertebral disc cell therapy for regeneration: mesenchymal stem cell implantation in rat intervertebral discs. Ann Biomed Eng 2004;32:430-4.
6. Cinotti G, Patti AM, Vulcano A, et al. Experimental posterolateral spinal fusion with porous ceramics and mesenchymal stem cells. J Bone Joint Surg 2004;86-B: 135-42
7. Akiyama Y, Radtke C, Honmou O, Kocsis JD. Remyelination of the spinal cord following intravenous delivery of bone marrow cells. Glia 2002;39:229-36.
8. Chen F, Hui JH, Chan WK, Lee EH. Cultured mesenchymal stem cell transfers in the treatment of partial growth arrest. J Pediatr Orthop 2003;23:425-9
9. Gussoni E, Soneoka Y, Strickland CD, et al. Dystrophin expression in the MDX mouse restored by stem cell transplantation. Nature 1999;401:390-4

Acetabulum fractures

FRACTURES OF THE ACETABULUM
Letournel and Judet Classification
• Letournel and Judet devised the column concept where the anterior column was formed by the iliopectineal component and the posterior column was formed by the ilioischial component.
• The acetabular dome is formed the junction of the two columns.
• Both the columns have an inverted Y shaped construct
• Based on degree of columnar damage, 10 fracture patterns occur-
5 “elementary” and 5 “associated”.

Elementary Patterns
1. Posterior wall #
2. Posterior column #
3. Anterior wall #
4. Anterior column #
5. Transverse #

Associated Patterns
1. T-shaped #
2. Posterior column and posterior wall #
3. Transverse and posterior wall #
4. Anterior column/Posterior hemitransverse #
5. Both columns #

Mechanism of Injury:
a) Direct trauma:
Direct impact to the greater trochanter forms a transverse fracture when the hip is in neutral position
Direct impact to the greater trochanter forms an anterior column fracture when the hip is externally rotated.
Direct impact to the greater trochanter forms a posterior column fracture when the hip is internally rotated.
b) Indirect trauma:
As in a dash type of injury with a flexed knee.

Clinical Features:• Airway, breathing and circulation should be assessed.
• Look for sciatic nerve injury (common peroneal nerve component) especially in posterior column fractures.
• Morel-Lavallée lesion: It is a localised area of subcutaneous fat necrosis over the lateral aspect of the hip caused by the same trauma that causes the acetabular fracture.

X-ray • AP view
• The obturator oblique view evaluates the anterior column (iliopectineal line) and posterior wall of the acetabulum. The obturator oblique view is obtained when the pelvis is rotated 45 degrees with the inured side up
• The iliac oblique radiograph – posterior column (ilioischial line or Kohler’s line), anterior wall of the acetabulum.
• Roof arc angle of Matta is calculated by drawing 2 lines, one vertical line along the geometric centre of the acetabulum and the other from the fracture line to the geometric centre. The medial, anterior and posterior roof arcs are calculated.


CT scans including 3-D CT:
• 3D CT helps in a better understanding of the fracture but may not clearly identify fractures with minimal displacement due to “averaging” phenomena

Treatment

Non-operative Treatment (Indications)
1. Minimally displaced fractures (<2 mm) in the weight-bearing dome.
2. Roof arc angle> 45 degrees.
3. Secondary congruence in both column fractures where the ball and socket configuration of hip is maintained.
4. No femoral head subluxation on three x-rays, taken out of traction
5. For posterior wall fractures: less than 40% of width of wall on CT

Roof arc angles are not used in posterior wall fractures.

Operative Treatment (Indications)
1. Mainly for displaced fractures in the weight bearing area.
2. Matta’s roof arc angle <45 degrees.
3. Inability to maintain a congruent joint out of traction
4. Cranial 10 mm of the acetabulum on the CT scan corresponds to the area defined as the weight-bearing dome by roof arcs. Fractures involving area in the upper 10 mm of acetabulum are treated operatively.

Applied anatomy:
• Corona mortis: is a vascular communication between external iliac and deep inferior epigastric artery and the obturator artery. May extend over the superior pubic ramus; average distance from the symphysis to corona, 6 cm
• The ascending branch of MCFA contributes to vascularity of femoral head; hence preservation of this artery while dissecting near the quadratus femoris is important.
• The superior gluteal neurovascular bundle exists through the greater sciatic notch, damage of this bundle can occur when the fracture line exits the greater sciatic notch.

Factors predicting a good outcome in acetabular fracture fixation:

• Injury to cartilage or bone of femoral head
Damage: 60% good/excellent result
No damage: 80% good/excellent result
• Anatomic reduction
• Age of patient: predictive of the ability to achieve an anatomic reduction


Posterior wall fracture:•
- Maybe single or multifragmentary
• Marginal impactions maybe present: This is a rotated and impacted osteochondral fragment that is displaced as the femoral head dislocates and the wall fractures
• CT scan helps to evaluate marginal impaction, loose fragments in the joint, evaluation of joint concentricity and estimation of size of posterior wall fragment.
• Kocher Langenback approach is used for fixation

Posterior column fracture:• Usually fractures the greater sciatic notch at or above the location of the superior gluteal neurovascular bundle, extends inferiorly through the roof of the weight bearing dome and exists through the obturator foramen
• Neurovascular bundle maybe entrapped in the fracture if the posterior column is widely displaced. It should be extracted prior to reduction of the fracture dislocation
• Letournel’s gull sign: the articular cartilage accompanying the displaced posterior acetabular segment hinges inward creating an image with the intact portion of the roof that looks like a bird in flight.
• Kocher Langenback approach is used for fixation

Anterior wall fractures:• May be associated with “thinning” or reduplication of the ilioischial line
• The teardrop is often displaced medially with respect to the ilioischial line.
• Ilioinguinal approach is used for fixation

Anterior column fracture:
• High anterior column fractures exit the iliac crest, intermediate fractures exit the anterior superior iliac spine (ASIS), low fractures exit the psoas gutter just below the AIIS, and very low anterior column fractures exit the bone at the iliopectineal eminence
• The roof or portion of it can be displaced medially as seen in high or intermediate anterior column fractures. This pattern may also be seen in anterior column-posterior hemitransverse fractures or both column fractures of the acetabulum.
• The more superiorly the fracture line ascends, the greater the involvement of the weight-bearing aspect of the acetabulum.
• Ilioinguinal approach is used for fixation

Transverse fractures:• breaks both the anterior and posterior border of the innominate bone
• separates the innominate bone into two pieces: the upper iliac piece and the lower ischiopubic segment

subdivided by where the fracture crosses the articular surface:
 Transtectal fractures cross the weight bearing dome of the acetabulum.
 Juxtatectal fractures cross the articular surface at the level of the top of the cotyloid fossa.
 Infratectal fractures cross the cotyloid fossa
• Transtectal fractures maybe fixed with extended iliofemoral approach or Kocher langenback approach
• Infratectal or Juxtatectal fractures are approached through the Kocher Langenback approach

Complications:
1. Nerve injury: Sciatic nerve injury is associated with posterior column fractures.
2. Surgical wound infection: abdominal and pelvic visceral injuries predispose to increased incidence of surgical wound infection.
3. Heterotopic ossification: the incidence is highest with the extended iliofemoral approach and second highest with the Kocher-Langenback. indomethacin or low-dose radiation are sued for prophylaxis
4. Avascular Necrosis
5. Chondrolysis