Quiz 3 - Spivak - Bone and Joint Flashcards
Osteomyelitis - How is it caused?
Result of trauma or surgery
Contiguous spread
Hematogenous - S aureus - thru blood
What happens in osteomyelitis?
Inflammatory exudate leads to increased intramedullary pressure and extension to cortex and periosteum
Blood supply interrupted which leads to necrosis - sequestra is separated dead bone
What is the development of osteomyelitis?
Initial infection -> Blood supply blocked -> Subperiosteal abscess -> Dead bone -> pus escape
Stage I - Osteomyelitis - ?
Stage II - “ - ?
Stage III - “ - ?
Stage IV - “ - ?
I - Medulla of bone
II - Superficial
III - Localized (cortical and medullary bone, but not entire diameter of bone)
IV - Diffuse - Entire bone and loss of stability
Acute vs chronic classification
Acute
- Infection prior to development of sequestra
- Usually less than 2 weeks
Chronic
- Infection after sequestra have formed
- Other hallmarks include formation of involucrum (new bone), bone loss, and sinus tract formation
Clinical presentation of acute osteomyelitis?
- Gradual onset over several days
- Dull pain/local tenderness
- Warm, erythemous, swelling, fevers may occur
- Can present as septic arthritis
Clinical presentation of chronic osteomyelitis?
- Mild pain over several weeks
- May have localized swelling or erythema
- Draining sinus tract
Diagnosis of osteomyelitis?
Clinical presentation may or may not bacteremia with typical organisms - bone pain with other symptoms
- Imaging, poorly healing wounds, diabetes mellitus, vascular disease, decubitus ulcers
- Need an MRI
- Blood tests
- Definitive diagnosis based on culture of bacteria from bone biopsy and pathology with inflammation and osteonecrosis
Acute osteomyelitis treatment?
3-6 weeks antibiotics may or may not need to debride abscess or due to instability
Difference b/t IV vs. oral antibiotic therapy not well established
Chronic osteomyelitis treatment?
3-6 weeks antibiotics, may or may not need surgery, but is common
Greater role for surgery due to necrotic bone and lack of drug penetration to devascularized bone (usually means an amputation)
T/F - Oral antibiotics are acceptable and actually more data in support of them than IV.
TRUE
T/F - Better cure rates of osteomyelitis with adjunctive surgical debridement.
TRUE
Osteomyelitis of the jaw - tell me about it.
Odontogenic infections can spread continuously to the jaw (oral aerobes and anaerobes)
Rare
Mandible more susceptible than maxilla due to thinner cortical plates and poorer vascular supply
What happens? Periosteum penetrated with chronic infection w/ formation of mucosal or cutaneous abscesses and fistulae- lingual aspect of posterior mandible at greatest risk
Risks: Dental infection, fractures, radiation, diabetes mellitus, steroid use
What are some symptoms of osteomyelitis of the jaw?
Mandibular pain, anesthesia/ paresthesia on affected side, lymphadenopathy and can progress to trismus
Treatment of osteomyelitis of the jaw?
Combo of surgery and antibiotics targeting oral flora
Definitive diagnosis of osteomyelitis of the jaw is helped by what?
Medication related osteonecrosis of the jaw
Antiresorptive (bisphosphonates) and antiangiogenic
In general, how does hematogenous osteomyelitis come about?
Bacteria in blood
Spinal cord injuries
Trauma
Surgery
- In adults - seen in spine
- In kids - seen in long bones
T/F - Joint replacements (arthroplasty) are highly effective and improve patients’ quality of life, mobility, and independence.
TRUE
What is the leading cause of arthroplasty failure?
Prosthetic joint infections (PJIs) - This leads to more surgery, prolonged antimicrobials - Difficult to treat with failure rates of 10-20%
What are some risk factors for PJIs?
Surgical site infection not involving joint prosthesis
Prior surgery at site of prosthesis
Extended operative times
Diabetes mellitus, immunosuppression
Microbiology of PJIs?
65% - Gram + cocci
-Coagulase-negative staph
—Aureus
-Streptococcus species
-Enterococcus species
6% of the microbiology of BJIs is from what bugs?
Aerobic gram - bacilli
- Enterobacteriacae
- Psuedomonas aeruginosa
Anaerobes account for what % of osteomyelitis?
4%
Propionibacterium species (shoulder arthroplasty)
Peptostreptococcus
Finegoldia magna
About _________% of osteomyelitis has been found to be polymicrobial.
20
How do bugs colonize on a prosthesis?
Using a biofilm that allows them to adhere to the surface
What is the definition of early PJI?
What are the clinical presentations of early PJI?
W/in 1-3 months, acquired during prosthesis implantation, virulent organisms (S aureus, gram negative)
Local erythema Swelling Pain Drainage Delayed healing May or may not have a fever
What is the definition of delayed PJI?
How is this presented clinically?
3 months - 2 yrs
Acquired during prosthesis implantation
Less virulent organisms (CoNS, P acnes)
Chronic pain
Draining sinus
What is the definition of late PJI?
How is this presented clinically?
> 1-2 yrs
Hematogenous seeding or late manifestation of surgical infection
Chronic pain
Draining sinus or acute septic arthritis with sudden pain (hematogenous)
Treatment = ? + ?
Treatment = surgery + antimicrobials
What are surgical options to cure osteomyelitis?
Debridement and retention Two stage exchange One stage exchange Resection arthroplasty w/ arthrodesis Amputation
T/F - In general, for patients with prosthetic joint implants, prophylactic antibiotics are NOT recommended prior to dental procedures to prevent prosthetic joint infection
TRUE
*Randy does this, probably as a CYA.
What is the antibiotic therapy associated with debridement and retention?
Staph Infection
- 2-6 wks of IV therapy + rifampin
- Follow by oral therapy + rifampin (Tetracycline, levofloxacin)
- Duration (IV + oral): THA - 3 months, TKA - 6 months
What is the antibiotic therapy for 1 stage exchange surgery?
Staph Infection
- 2-6 wks of IV therapy + rifampin
- Follow with oral therapy + rifampin (Tetracycline, levoloxacin)
- Duration (IV + oral): 3 months
What is the antibiotic therapy for 2 stage exchange surgery?
4-6 wks IV therapy or highly bioavailable oral therapy
- Rifampin NOT recommended b/c prosthesis removed
- Antibiotic-impregnated cement spacer used to maintain limb length (May decrease infection recurrence)
- Re-implantation (stage 2): 6 wks - 3 months
How is osteomyelitis classified?
Based on chronicity and whether hematogenous or contiguous
Conclusions about bone and joint infections?
- Treatment for bone and joint infection involve antibiotics and surgical debridement
- NO role for antibiotic prophylaxis prior to dental procedures to prevent orthopedic implant infection in most patients
