Case studies and clinical papers: Musculoskeletal infections

Chronic draining sinus with Serratia in left ankle

69-year-old patient endured fifteen surgeries prior to presenting with chronic draining sinus. He was hospitalised and cultures tested positive for Serratia.

Transform osteomyelitis in diabetic foot

67-year-old male with type 2 diabetes and BMI of 37 presented with osteomyelitis and interphalangeal joint destruction to his left hallux.

Infected revision THA

84-year-old male presented with a painful left hip 18 years after a total hip arthroplasty procedure.

Bilateral femoral fractures

50-year-old female presented with bilateral high energy fractures due to a motor vehicle accident with prolonged extrication.

Infected Knee Joint

45-year-old female presented with 6 months’ history of knee pain and swelling. This patient had undergone allograft reconstruction of the anterior cruciate ligament 9 months prior.

Transform osteomyelitis caused by Group B Streptococcus and MRSA

73-year-old female with osteomyelitis caused by Group B Streptococcus and MRSA infection.

Transform infected humerus

44-year-old female presented with persistent and severe pain of the right arm. She had a history of infection following a nailing of the humerus 15 years ago.

Transform osteomyelitis caused by MRSA

40-year-old male with osteomyelitis caused by MRSA infection. Presented with drainage, failure of fixation and non-union 6 months after the initial ORIF calcaneus due to a 20ft fall.

Transform infected revision arthroplasty

Infected total knee replacement 2 years after primary procedure.

Transform infected trauma

Infected femoral nail and non-union of left femur with persistent discharging wounds proximally and distally.

Transform infected revision arthroplasty

35-year-old male presented with recurrent periprosthetic infection after complex hinged total knee replacement (TKR), performed 1 year ago, to treat severe post-traumatic knee osteoarthritis.

Transform osteomyelitis in diabetic foot

A 67-year-old male patient with Type 2 diabetes presented with a 1 year history of a right foot ulcer and symptoms of infection with osteomyelitis caused by Staphylococcus aureus.

Some papers require users to submit their contact details before downloading

Dissolvable antibiotic beads in treatment of periprosthetic joint infection and revision arthroplasty. The use of synthetic pure calcium sulfate (Stimulan) impregnated with vancomycin & tobramycin

McPherson EJ, Dipane MV, Sherif SM. Reconstructive Review 2013;3(1):32–43.

Purpose: A study to review the clinical results in 250 cases of aseptic and septic revision total hip and total knee arthroplasty using antibiotic-loaded (vancomycin and tobramycin) STIMULAN beads.

Results: In all cases, STIMULAN had completely absorbed. Out of 250 cases there were 29 complications (11.6%) – 11 hips and 18 knees. These included 8 wound complications, 9 failures of which only 6 were the result of infection.

The incidence of wound drainage was very low with 8 cases reported (3.2%) – 5 knees and 3 hips. Heterotopic bone formation was also very low with 3 cases (1.2%) – 1 knee and 2 hips.

Managing lower-extremity osteomyelitis locally with surgical debridement and synthetic calcium sulphate antibiotic tablets

Gauland C. Adv Skin Wound Care 2011;24(11): 515–523.

Purpose: An evaluation of 323 patients with clinically confirmed chronic osteomyelitis of the lower extremity, following debridement and implantation of STIMULAN beads.

Results: Of the 323 patients evaluated, 303 (93.8%) were cleared of infection with no reoccurrence within the 5-year evaluation period. 86.4% of the patients who healed did so without the concurrent use of IV antibiotics. The author did not experience the complications (excessive effusion) previously described using mined and refined calcium sulfate source.

The use of antibiotic impregnated, implanted synthetic calcium sulfate tablets in the treatment of soft tissue, vancomycin-resistant enterococcus infections

Gauland C, In The Symposium on Advanced Wound Care and Wound Healing Society Annual Meeting. 2011: Gaylord Texan Hotel & Convention Center, Dallas, Texas.

Purpose: A clinical study of 5 patients presenting with soft tissue, vancomycin resistant enterococcus (VRE) infection to the foot, all facing amputation.

Results: Within 24 hours of STIMULAN bead implantation all 5 patients responded with a reduction of both clinical signs of infection and wound drainage. Within 4 days, all 5 patients showed no clinical, laboratory or radio-graphical signs of infection, and by day 28 all wounds had resurfaced with no clinical or radiographical signs of infection.

Infected non-union of radius and ulna – strategy of approach

Parihar M and Ahuja D. Journal of Orthopaedic Case Reports 2012 Oct-Dec;2(4):26–31.

Purpose: A clinical case study of an infected non-union of the radius and ulna, including the strategy of approach to the case, as infected non-unions of the forearm are rarely encountered.

Results: 1-year post-surgery radiographs show solid union at all the four sites, without additional procedures being required. The patient is infection-free and back to an active life, with fairly good function.

The influence of third body damage with bone void fillers on the wear of UHMWPE

Cowie RM, Carbone S, Aiken S, Cooper JJ, Fisher J, Jennings LM. Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds, UK Biocomposites Ltd, Staffordshire, Keele, UK.

Purpose: In this study, damage to cobalt chrome plates caused by third body particles from bone cement and the bone void fillers was assessed. This was followed by wear tests of UHMWPE against the plates using a 6 station multi-axial pin on plate rig.

Results: It is evident that third body particles from bone void fillers or bone cement can scratch cobalt chrome counter faces, however no damage could be measured from STIMULAN. It was also determined under the wear test conditions used, to increase wear of UHMWPE, the surface damage must be severe with scratches requiring a lip height of over 2 μm.

Treatment of experimental osteomyelitis caused by methicillin-resistant Staphylococcus aureus with a synthetic carrier of calcium sulfate (STIMULAN) releasing moxifloxacin

Kanellakopoulou K et al. Int J Antimicrob Agents 2009;33(4):354–359.

Purpose: An in vivo study to assess the efficacy of STIMULAN in experimental bone infection caused by methicillin-resistant Staphylococcus aureus (MRSA).

Results: Pharmacokinetic analysis showed sustained release of moxifloxacin by Stimulan for almost 35 days with the greatest eluted concentration at day 7. Concentrations at the site of implantation were almost 300 times greater than MIC for MRSA and these concentrations remained at this high level within 3 cm around the site of implantation. Serum and soft tissue concentration levels remained low; moxifloxacin was detected only within the first 7 days after implantation in the systemic circulation at limited amounts of 0.56 μg/ml dropping to 0.10 μg/ml thereafter. These findings make systemic toxicity unlikely.

Elution and efficacy of colistin when combined with a synthetic calcium sulfate

Laycock PA, Cooper JJ, Brayford. Biocomposites Ltd, Keele, Staffordshire, UK. (Poster presentation) 33rd Annual Meeting of the European Bone & Joint Infection Society, Utrecht, The Netherlands 2014

Purpose: The emergence of multi-drug resistant Gram-negative bacteria is a serious threat to health. The polymyxin antibiotic colistin may be the last line of defence against these pathogens in the 21st century. This study establishes the potential of STIMULAN to mix with, set and elute colistin in bactericidal concentrations while systemic levels and associated side effects remain low.

Results: Colistin sulfate will mix, set and elute from STIMULAN at bactericidal levels. Eluate levels remained above MIC for 100% of 561 P. aeruginosa isolates and 100% of 31 A. baumannii isolates out to 3 days. Both microorganisms tested for zone of inhibition (ZOI) showed susceptibility to colistin eluted from STIMULAN beads. Higher sustained colistin elution levels were achieved when rifampicin was added as a second antibiotic.

A simple acoustic technique to assess the setting time of antibiotic loaded calcium sulphate

Laycock PA, Brayford MJ, Cooper JJ. Product Development. Biocomposites Ltd, Keele, Staffordshire, UK.

Purpose: Calcium sulfate hemi-hydrate when mixed with water results in the formation of a solid precipitated calcium sulfate dihydrate. Many factors affect the timing of this reaction, hence the need to quantify set times. This work developed a new simple acoustic technique to measure the setting times of a calcium sulfate bone cement loaded with different antibiotic mixes.

Results: A new simple acoustic test has been developed and used to assess the effect of different antibiotic additions on the setting time of a ‘rapid cure’ calcium sulfate bone cement (STIMULAN). This technique gives ‘absolute’, reproducible and consistent results and can be used with very small quantities of cement.

Assessing the influence of third body damage to articulating surfaces with bone void fillers

Purpose: Third body particles such as those from bone cements and bone void fillers when trapped between articulating surfaces can accelerate wear of arthroplasty materials leading to premature failure. In this two phase study the damage to cobalt chrome (CoCr) by PMMA bone cement, STIMULAN and a competitor calcium sulfate material was investigated. Damage simulation was evaluated using pin on disk testing and compared to that of control samples.

Results: Phase 1 damage simulation showed that STIMULAN resulted in no third body damage - causing no significant damage to cobalt chrome. Phase two results showed no additional damage to CoCr disks as a result of the STIMULAN, with results comparable to negative controls, where no third body material is present.