Hip Arthroplasty Infection
The HAIBA case definition of hip arthroplasty infection
The HAIBA algorithm is based on operation and diagnosis codes from the National Patient Register (LPR) and microbiological sample responses from the Danish Microbiology Database (MiBa).
Primary hip arthroplasty (index surgery, see surgery codes below) is divided into acute and planned surgery, using diagnosis codes (see classification below).
The patient is followed for infections from 2 to 90 days after the index surgery and up to 365 days. Patients with bilateral index surgery have two parallel follow-up periods.
An infection is recorded if a relevant re-operation has been recorded and at least two out of a minimum of three biopsy tests are positive for the same microorganism.
HAIBA case definition of hip arthroplasty (index operation)
Notes on surveillance data from HAIBA
Figures for infections occurring 2-90 days after the index surgery are provided online as the majority of infections occur in this period.
Figures on infections after acute index operations are not presented online, but data on these infections and on infections occurring 91-365 days after the index operations are made available to each of the Danish regions.
Data from HAIBA cover the past five full calendar years and the current year. The number of infections is estimated on a monthly basis in relation to the date of the index operation.
Which department/hospital are infections attributed to?
Infections are listed according to the date of the operation and the department where the operation was performed. As an example: An index operation was performed in Department X on January 2, 2016. Re-operation, during which an infection was found, was performed in Ward Y on February 10, 2016.
This infection is recorded in HAIBA as an infection in Department X on January 2, 2016.
How is incidence calculated?
The incidence of these infections is calculated as a risk or cumulative incidence fraction, i.e. the number of infections per 100 index operations.
The HAIBA algorithm is based on primary hip replacements (index operations), which are defined by the operation codes from the LPR listed below. Surgery codes follow the Danish version of
NOMESCO Classification of Surgical Procedures.
Operation codes and texts:
KNFB20 - Primary total prosthetic replacement of hip joint not using cement
KNFB30 - Primary total prosthetic replacement of hip joint using hybrid technique
KNFB40 - Primary total prosthetic replacement of hip joint using cement
Acute operations are separated from planned index operations by diagnosis codes; all index operations with a DS7* diagnosis code ("lesions of the hip and thigh") are marked as acute and all others as planned operations.
Diagnosis codes follow the International Classification of Diseases (in Danish), 10th version (ICD-10) classification system.
Relevant reoperations are defined by the following operation codes from the LPR.
Operation code and text:
KNFA02A - Open exploration of soft tissue of hip
KNFA12 - Open exploration of hip joint
KNFA22A - Open biopsy of hip joint
KNFA22C - Open biopsy of soft tissue of hip
KNFC20 - Secondary total arthroplasty uncemented, cup rev.
KNFC21 - Secondary total arthroplasty uncemented, stem rev.
KNFC22 - Sec. imp. of distal comp. total prothesis in hip joint not using cement
KNFC23 - Sec. imp. of other comp. total prothesis in hip joint not using cement
KNFC29 - Sec. imp. of unspecified comp. total prothesis in hip joint not using cement
KNFC30 - Sec. imp. of both comp. hybrid total prothesis in hip joint
KNFC31 - Sec. imp. of proximal comp. hybrid total prothesis in hip joint
KNFC32 - Sec. imp. of distal comp. hybrid total prothesis in hip joint
KNFC33 - Sec. imp. of other comp. hybrid total prothesis in hip joint
KNFC39 - Sec. imp. of unspecified comp. hybrid total prothesis in hip joint
KNFC40 - Sec. imp. of both comp. total prothesis in hip joint using cement
KNFC41 - Sec. imp. of proximal comp. total prothesis in hip joint using cement
KNFC42 - Sec. imp. of distal comp. total prothesis in hip joint using cement
KNFC43 - Sec. imp. of other comp. total prothesis in hip joint using cement
KNFC49 - Sec. imp. of unspecified comp. total prothesis in hip joint using cement
KNFC59 – Sec. Imp. of interposition prosthesis in hip joint
KNFC99 – Sec. other prosthetic replacement in hip joint
KNFF02 - Open total synovectomy of hip joint
KNFF12 - Open partial synovectomy of hip joint
KNFG09 - Excision arthroplasty of hip joint
KNFG19 - Interposition arthroplasty of hip joint
KNFG29 - Other arthroplasty of hip joint without prosthetic replacement
KNFG49 - Fusion of hip joint with internal fixation
KNFG59 - Fusion of hip joint with external fixation
KNFH32 – Open Freeing of adhesions of hip joint
KNFH92 – Other open operation on hip joint
KNFK29 - Fenestration or forage of femur
KNFM79 - Excision of bursa of hip or thigh
KNFQ09 - Exarticulation of hip
KNFQ99 - Other amputation or related operation on hip or femur
KNFS19 - Incision and debridement of infection of hip joint
KNFS29 - Incision and debridement of infection of femur
KNFS49 - Incision and debridement of infection of hip joint with introduction of therapeutic agent
KNFS59 - Incision and debridement of infection of femur with introduction of therapeutic agent
KNFS99 - Other operation for infection of tendon, joint or bone of hip or thigh
KNFU10 - Removal of both comp. total prosthesis from hip joint
KNFU11 - Removal of proximal comp. total prosthesis from hip joint
KNFU12 - Removal of distal comp. total prosthesis from hip joint
KNFU19 - Removal of unspecified comp. total prosthesis from hip joint
KNFU99 - Removal of other implant from hip joint or femur
KNFW59 - Reoperation for superficial infection in surgery of hip or thigh
KNFW69 - Reoperation for deep infection in surgery of hip or thigh
KNFW89 - Reoperation for deep haemorrhage in surgery of hip or thigh
KNFW99 - Other reoperation in surgery of hip or thigh
The following codes are used to identify all samples taken as Kamme biopsies. These are material codes from Mikrobiologisk Diagnose System (MDS). Read more about the MDS.
Material code and text:
40000 - Tissue
40010 - Biopsy
40030 - Bone tissue
40035 - Package Kamme biopsies
40065 - Joint capsule tissue
All biopsies with sampling time in the interval from 24 hours before re-operation to 48 hours after re-operation are treated as a single set of biopsies.
All microorganisms are treated the same in this algorithm, i.e. we apply no special rules for any specific microorganisms.
