Multiresistant Osteomyelitis and Implant Failure Resolved with Simini Intraoperative and Post-Operative Drain Lavage
ABvet Klinika · Left Tibia/Fibula · Second Revision with Simini Protocol
Case Summary
A 2-year-old male mixbreed dog presented with a tibia and fibula fracture sustained from a bite injury one month prior, initially treated at another clinic. At presentation, he was non-weight-bearing with persistent secretion, fistulation, leukocytosis, and elevated CRP. Radiographs showed implant failure and atrophic non-union. FNA confirmed infection with multiresistant Enterobacter hormaechei and E. coli.
Following a first revision surgery without Simini, implant failure recurred. The second revision included Simini Protect Lavage intraoperatively and via a post-operative drain for 3 days. Wound healing was significantly faster than after the first revision (complete at 12 days), bacteriology was negative at 3 months, and progressive bone union was confirmed at monthly radiographic rechecks.
Clinical Presentation
Referral with Non-Union, Implant Failure and Multiresistant Infection
The patient presented one month after a bite-injury tibial fracture treated at another clinic. Clinical signs at presentation included complete non-weight-bearing, persistent wound secretion, and fistulation. Bloodwork confirmed leukocytosis and markedly elevated CRP consistent with active systemic infection.
Radiographic evaluation showed implant failure at the fracture site and atrophic non-union — indicating failure of both fixation stability and biological healing. Fine needle aspirate confirmed infection with two organisms.
Causative Organisms — Multiresistant
FNA confirmed co-infection with Escherichia coli and Enterobacter hormaechei. Enterobacter hormaechei is classified as a multiresistant organism and is a recognised challenge in implant-associated orthopaedic infections, with limited antibiotic options and high capacity for biofilm formation.
First Revision Surgery — Without Simini
Initial Revision and Recurrent Implant Failure
The first revision surgery involved removal of the failed original implant, debridement of necrotic and devitalised tissue, betadine irrigation, and application of synthetic bone graft with antibiotic. Following this procedure, the surrounding soft tissue healed and secretion resolved. However, bone healing remained insufficient. Two months post-surgery, the bone plate failed again. Repeat bacteriology confirmed persistent Enterobacter hormaechei infection.
First Revision (No Simini)
Soft tissue healed — bone healing failed
Secretion and fistulation resolved. However, bone healing was inadequate and the plate failed at 2 months. Persistent Enterobacter hormaechei on repeat culture.
Second Revision (With Simini)
Wound healed in 12 days — bone union achieved
Significantly faster wound healing than first revision. Complete wound closure at 12 days with no fistula or recurrent secretion. Progressive bone union confirmed at monthly rechecks.
Second Revision Surgery
Orthogonal Plating, Simini Lavage and Post-Operative Drain Protocol
The second revision surgery involved removal of the failed implant, shortening and revitalisation of bone fragments, and stabilisation with orthogonal plating. Simini Protect Lavage and NaCl were applied repeatedly during the procedure. A post-operative drain was placed for 3 days with daily Simini lavage via the drain.
| Step | Description |
|---|---|
| 01 | Failed implant removed. |
| 02 | Shortening and revitalisation of bone fragment ends performed. |
| 03 | SiminiSimini Protect Lavage and NaCl applied repeatedly during the procedure. |
| 04 | Orthogonal plating used for stabilisation — dual plate configuration. |
| 05 | Post-operative drain placed. |
Post-Operative Drain Lavage Protocol — Days 1 to 3
Patient mildly sedated with analgosedation once daily for drain procedure.
5 ml of Simini Protect Lavage applied via drain.
2 minute dwell time observed.
Irrigation with NaCl performed after dwell. Drain removed after Day 3.
Fig. 1 — Post-operative radiograph, VD view. Orthogonal LCP plate fixation of the left tibia following second revision surgery. Dual plate configuration used for enhanced stability.
Fig. 2 — Post-operative radiograph, lateral view. Orthogonal plating in situ. No periimplant lucency visible at post-operative assessment.
This case involved multiresistant E. coli and Enterobacter hormaechei infection with two prior implant failures. Simini Protect Lavage was applied both intraoperatively (repeated lavage during the procedure) and post-operatively via a surgical drain over 3 days. Wound healing was complete at 12 days — notably faster than the first revision. Bacteriology was negative at 3 months. Progressive bone union was confirmed at monthly radiographic rechecks. This protocol demonstrates Simini's utility in the highest-complexity revision scenarios involving multiresistant organisms and failed prior interventions.
Outcomes
Wound Healing, Bacteriology and Bone Union
Following the second revision with Simini Protect Lavage intraoperatively and via drain, outcome was markedly improved compared to the first revision.
Wound Fully Healed
Complete wound healing at 12 days post-surgery — significantly faster than following the first revision.
Bacteriology Negative
Bacterial culture confirmed negative at 3 months. Multiresistant pathogens no longer detected.
Progressive Bone Union
Radiographic rechecks confirmed progressive bone union at monthly intervals following the second revision.
Fig. 3 — Follow-up radiograph (01/03/2024), left stifle and tibia. Progressive bone union at the fracture site confirmed. No signs of osteomyelitis or periimplant lucency at follow-up.
This case represents a single-centre experience at ABvet Klinika. The Simini protocol (intraoperative + post-operative drain) was used at the second revision only; the first revision did not use Simini.
Follow-Up Timeline
Post-Operative Course
Initial Injury
Bite injury with tibia/fibula fracture treated at prior clinic.
First Revision
Revision surgery without Simini. Soft tissue healed; implant failure recurred at 2 months.
Second Revision + Simini
Orthogonal plating with intraoperative Simini lavage and post-op drain protocol.
Post-Op Drain Protocol
Daily 5 ml Simini via drain, 2-minute dwell, NaCl rinse.
Wound Healed
Complete wound healing confirmed.
Bacteriology Negative
Culture negative. Multiresistant pathogens cleared.
Bone Union Progress
Progressive union confirmed at each monthly radiographic recheck.