DDH – Dysplasia

DDH-dysplasia
Approach to DDH – Acetabular Dysplasia

– after treating the dislocation, you must follow the kid to see if the acetabulum is developing normally.
Look to see what the pathology is:
– is it dysplasia of the acetabulum with a shallow cup – acetabular index down, sharp angle down?
– is it a coxa valga with superior loading?
– is it both?

– is the dysplasia causing recurrent instability? Then you better get on with an osteotomy
– if reduced, it is somewhat controversial to decide when to do the osteotomy – wait for remodeling, or just go ahead and do it to encourage better remodeling? Probably a more aggressive approach is warranted – if the acetabulum is not developing normally after a couple visits to the clinic, pull the trigger.

Reconstructive osteotomies.

– cannot have degenerative arthritis
– should have a good range of motion (how good is debatable)
– should check an abduction/internal rotation x-ray to assess two things: congruency and coverage. On this view the head and acetabulum should be CONGRUENT to proceed with a re-directional osteotomy (Salter, Triple, Steel). If reduced but not completely congruent, consider acetabuloplasty – Dega, Pemberton (more in the CMT or paralytic population). If not reducible – need a salvage procedure (Chiari or Shelf).
– look at the femoral neck shaft angle – is the deformity there? Does it need a varus osteotomy? Most have lots of anteversion and not that much valgus, so a varus osteotomy runs the risk of elevating their GT and causing an abductor limp. If doing a varus osteotomy, remember to medialize the femur with the offset on the plate.

RA Finger Deformities 3

Finger Deformities 3
TENDON RUPTURE

Extensor Tendon

– basically caused by rheumatoid tenosynovitis
– the long extensors of the middle, ring, and little fingers rupture as a group – usually related to the dorsal subluxation of the distal ulna, forcing the tendons to rub up against the rough bone and the dorsal carpal ligament
– acutely, direct repair may be done.
– chronically, a segmental tendon graft will be required
– potential graft sources are the extensor indicis, EPB (especially when the MCP is going to be fused anyways), or sublimis to the ring finger

Flexor Tendon

– not as common to rupture as the extensor tendons, but harder to treat
– tendon grafts almost always fail.
– FPL rupture may be treated with thumb IP fusion

ARTHRODESIS OF THE FINGER JOINTS

– preferred position for arthrodesis:
MCP – 20-30o flexion
PIP – 25o flexion in the index to 40o in the small
DIP – 15-20o flexion

DEFORMITIES OF THE THUMB

– Nalebuff classification of thumb deformities in rheumatoid patients

Type I: boutonniere deformity
– synovitis at the MCP stretches the extensor hood; the EPL migrates medially and causes flexion of the MCP joint, extension of the IP joint, and volar subluxation of the proximal phalanx
– if mild, MCP synovectomy and extensor reconstruction suffice
– if severe, MCP arthrodesis (if IP and CMC joint function are intact)
– if IP and CMC are involved, MCP arthroplasty may be better

Type II: MCP flexion, IP hyperextension, plus CMC subluxation
– treat with all of the above plus CMC arthroplasty

Type III: swan neck deformity
– begins with synovitis at the CMC joint, subluxing the trapeziometacarpal joint laterally; an adduction contracture of the metacarpal develops, and the MCP joint hyperextends as the result of the extension forces on the MCP joint and laxity of the volar plate.
– if mild, trapeziometacarpal interposition arthroplasty
– if the MCP joint is very deformed, both trapeziometacarpal interposition arthroplasty and MCP fusion may be necessary

Type IV: ulnar collateral ligament laxity (Gamekeeper�s thumb)
– for mild deformities, synovectomy, ligament reconstruction and adductor release
– for severe deformities, MCP arthrodesis

RHEUMATOID DEFORMITIES OF THE WRIST

– the wrist may be the first location of painful swelling
– persistent swelling at the dorsum of the wrist for 6 weeks failing medical treatment may be an indication for synovectomy, as prophylaxis against extensor tendon rupture
– on the volar surface, even a small bit of tenosynovitis can cause carpal tunnel syndrome
– the level of the deep transverse carpal ligament is a frequent site of rupture of flexor tendons

Arthrodesis

– whether arthrodesis or arthroplasty is best in the wrist is controversial.
– arthrodesis provides a painless, stable wrist with the chance to correct deformity
– most consider it the procedure of choice for marked flexion deformity of the wrist and fingers, for carpal dislocation, or for a painful wrist with associated tendon ruptures

STT Fusion

STT Fusion
Technique of STT Fusion (For Keinbock’s Disease)

– the exposure is a transverse incision
– the initial interval goes between EPL and ECRB
– watch out for superficial branch of the radial nerve
– take EPL radially first to deal with the scaphoid and trapezoid
– then take EPL ulnarly to deal with the trapezium, which is quite deep in the wound
– take off the radial styloid if doing it for SLAC wrist
– K-wire trapezoid to scaphoid – don’t actually need to K-wire to trapezium

Physeal Bar Post Femur Fracture

Approach to the Physeal Bar after Distal Femur Fracture

The distal femoral physis is vulnerable to growth arrest after Salter I and II injuries because of the high energy and undulating morphology of the plate – the injury may go through the resting and proliferating zone of cartilage cells

Treatment depends on age and degree of growth disturbance

Be aware that 40% of the limb growth is at the distal femoral physis; it typically contributes 7-10 mm of longitudinal growth per year!

Therefore – if 5 years of growth remaining and the whole physis has shut down – anticipate 5 cm leg length discrepany at least.

Consider: shoe lift, contralateral epiphyseodesis of femur and tibia

Resect physeal bar if less than 50% – map with MRI; approach from the metaphyseal side, resect until you see normal physeal cartilage, then fill with fat or cement. Leave metal markers in place to tell you how things are growing later.

If varus or valgus of more than 10 degrees exists at the time of resection – correct that too with a distal femoral osteotomy.
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THA – Approach to Dislocating THA

Dislocating THA
Approach to the Dislocating Total Hip Arthroplasty

Patient Factors:
Age
Sex – Female > Male
Non-compliance – ETOH, dementia, stupidity

Etiology Factors:
Dysplasia – weak abductors
Fracture – dislocation is much higher in femoral neck fractures treated with primary THA

Surgery Factors:

1. Sepsis

2. Approach – Posterior vs anterior

3. Malposition of components

A. Acetabulum – excessive retroversion – posterior dislocation
– excessive anteversion – anterior dislocation

B. Femur- excessive retroversion – posterior dislocation
– excessive anteversion – anterior dislocation

4. Component Factors

Head Size – the larger the more stable

Acetabular Rim Elevation – may increase posterior stability, but may impinge and cause dislocation out the front

Offset – the more offset, presumably the more tension on the abductors and the more stable the component will be

The �Head : Neck Ratio� – the ratio of the head diameter and the neck diameter – if the neck diameter is enlarged secondary to a skirt, the head/neck ratio decreases, and the component is more apt to impinge and dislocate

5. Soft Tissue Factors

– impingement – from soft tissue scar or heterotopic ossification
– abductor strength

TKA – Approach To Patellar Fracture

TKA – Approach to Patellar Fracture

Factors Associated with Patellar Fractures
1. Trauma (intuitive) 5. Vascular Compromise
2. Patellar Instability 6. Increased Flexion
3. Component Design 7. Improper Patellar Resection
4. Component Malposition 8. Revision TKA

Patellar Instability
– eccentricity and magnitude of patellofemoral loads increase with patellar subluxation, thus enhancing risk of fracture.
– instability is probably a HUGE factor

Improper Patellar Resection
– too much resection, too little resection, or asymmetric resection can all increase the change of fracture
– leaving less than 15 mm of patella after the resection significantly increases the strain in it
– taking too little also overstuffs the patellofemoral joint
– asymmetric resection basically refers to the mistake of taking too much off the lateral facet – remember, it is not a symmetric wafer that you are cutting off the patella – it should be very thin on the lateral side

Vascular Compromise
– the lateral release may sacrifice the superior lateral geniculate artery supply; the medial supply is cut when you do the medial parapatellar incision, so this lateral supply is more important
– the intraosseous supply comes from a midpatellar vessel in the middle one third, then a polar supply from the fat pad distally, and a proximal supply from the quadriceps tendon
– the clinical significance of AVN is unknown – if you see it, just leave it
Component Malposition
– elevation of the joint line causes patella baja and can increase stress on the component
– lower extremity alignment, or coverage of the patella by the prosthesis
(this may all relate to patellar instability)

Increased Flexion
– patients that can flex > 95 generate high patellofemoral compressive forces

Management

– depends on fracture pattern, location, remaining bone stock, integrity of bone-cement-component interface, and competence of extensor mechanism

If non or minimally displaced and extensor mechanism is intact – treat in a cast in extension, 6 weeks
If displaced or extensor mechanism is not intact – need to do something. Is the component stable?
– consider whether the fracture is such that you can fix it if the component is stable. Cerclage wiring or screws
– if unfixable, consider partial or complete patellectomy – may be more predictable than ORIF
– alternatively, if unfixable, consider removing the patellar component and letting the bone heal, anticipating that you might reconstruct it at a later date.

White and Panjabi

White/Panjabi
C-spine Instability

White & Panjabi criteria:
– anterior elements = 2
– posterior elements = 2
– sagittal translation > 3.5 mm or 20% of vertebra = 2
– sagittal rotation > 11o = 2
– positive stretch test = 2
– cord damage = 2
– root damage = 1
– abnormal disc narrowing = 1
– dangerous loads anticipated = 1

unstable if total score > 5

MCQs – Lower 1

MCQs-Lower 1
MCQs-Lower extremity

– gastrocs acts as a load absorber during early stance

– partial thickness meniscal tears and full-thickness stable, vertical or oblique tears measuring less than or equal to 10 mm may be left alone.

– during flexion of the knee, the medial meniscus moves 5 mm, the lateral moves about 10; note that the medial meniscus has less mobility – and hence is more prone to getting torn,.

– the most common mechanism of injury of the Achilles tendon is forced dorsiflexion of the plantarflexed foot

– remember to look on the lateral knee x-ray for the height of the patella! If it is way up there – there will be an extension lag.

– in the combined ACL MCL injury, probably best to wait for the knee to be rehabbed before doing anything.

– activity induced osteitis pubis is an overuse syndrome – hot on bone scan on both sides of the symphysis.

– for the patient who has posterior and external rotation displacement at 30 but not at 90, he has a posterolateral complex injury with an intact PCL. Isolated PCL disruption leads to increased posterior translation at 90, but not 30.
– increased external rotation at 30, BUT not at 90 – think posterolateral corner tear!

– “stingers” are neuropraxias of the brachial plexus – the recovery time is variable, anywhere from 2 days to several months. Residual sequela such as permanent muscle atrophy, can also occur and these patients need proper rehab. Do an EMG to define the extent of the injury. These patients should not be allowed back into contact sports until you’ve sorted out their injury

– with the ankle loaded and in neutral, the most important structure in resisting inversion is the bony tibial and talar articulation. In the absence of axial loading, the anterior talofibular and calcaneofibular ligaments are the primary restraints to inversion laxity.

– meniscal cysts are usually lateral, but can be medial. They are usually associated with horizontal cleavage tears – allow fluid out in a ball-valve type mechanism. They are treated by partial meniscectomy and decompression of the cyst into the knee.

– if using interference screws for bone plug fixation, use a screw the same length as the graft bone – if there is a 20 mm length of bone plug, use a 20 mm screw. If you use a longer screw, some of the threadas may cut the tendon graft.

– acute hemarthrosis of the knee alters quads strength by inhibiting muscle firing. The capsular distention, irritation, and pain caused by the effusion inhibits normal motor unit activation and firing.

– for osteochondral lesions of the talus caused by trauma – most are anterolateral; if displaced – open or scope them, consider fixing the fragment or excising it and drilling the base.

– doing a Chrisman Snook lateral ankle ligament reconstruction may cause symptomatic restriction of subtalar motion, because the calcaneofibular arm of the reconstruction crosses the subtalar joint at a different angle than the native CFL.

– os trigonum syndrome presents with posterolateral ankle pain as the posterior process of the talus impinges against the calcaneus with forced plantar flexion. The key is the forced passive plantar flexion causing pain.

– anabolic steroids increase muscle strength; the nonreversible side effect – alopecia (cystic acne, decreased sperm, testicular atrophy, and increased LDL are all reversible); the best test is LDH liver isoenzymes.

– arthroscopic debridement of an arthritic knee has the best chance of working if the normal alignment is maintained. It has poor results in patients with ligamentous laxity, loss of joint space, or abnormal alignment (varus)

– for ACL graft placement – the femoral tunnel placement is key; the tibia is abit more forgiving because the zone of isometricity is larger. If the graft is placed to far forward on the femur, it will be too tight in flexion. If it is too far back, it will be too tight in extension (over the top).

– the anterior horns of the medial and lateral menisci often serve to prevent

Osteoid Osteoma

Osteoid Osteoma

– small circumscribed osteoblastic lesion
– presents most frequently in males in 2nd decade
– proximal femur affected in 30%

Signs & Symptoms:
– dull pain that is worse at night
– relieved by ASA
– may cause localized swelling or limp depending on location

Xrays:
– lucent ‘nidus’ surrounded by dense reactive bone
– usu

Amputations II – 7

AMPUTATIONS 7
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REFERENCES

American Academy of Orthopaedic Surgeons, Atlas of Limb Prosthetics, Surgical and Prosthetic Principles, C.V. Mosby Company, 1981.

American Academy of Orthopaedic Surgeons, Atlas of Orthotics, Biomechanical Principles and Application, 2nd ed., C.V. Mosby Company, 1985

Murdoch, G., Wilson, A.B., Amputation, Surgical Practice and Patient Management, Butterworth Heinemann, 1996

Haimovici, H., Haimovici’s Vascular Surgery, Chapter 102: Amputation of the Lower Extremity: General Considerations, Chapter 105: Below-the-Knee Amputations, Chapter 106: Above-the-Knee Amputations., Blackwell Science, 1996

Czerniecki, J.M., Rehabilitation in Limb Deficiency, Arch Phys Med Rehabil. Vol 77, S 3-8, March 1996

Malawer, M., Postoperative Infusional Continuous Regional Analgesia, Clin Orthop Rel Research., Vol 266, pg 227-237, May 1991.

Dellon et al., Implantation of Sensory Nerve into Muscle: Preliminary Clinical and Experimental Observations on Neuroma Formation, Ann Plast Surg., Vol 12, pg 30-40, 1984.