International Orthopaedics (SICOT) DOI 10.1007/s00264-014-2621-6
ORIGINAL PAPER
Introducing prospective national registration of knee osteotomies. A report from the first year in Sweden Annette W-Dahl & Lars Lidgren & Martin Sundberg & Otto Robertsson
Received: 13 November 2014 / Accepted: 25 November 2014 # SICOT aisbl 2014
Abstract Purpose Knee osteotomy is a joint preserving surgery with new techniques and implants introduced during recent years. However the information of its use and outcome is scarce. A national knee osteotomy register was started in Sweden in 2013 from which we report here the information gathered during the first year of registration. Methods All patients having knee osteotomy (distal femur and proximal tibia), primaries and re-operations are intended to be included in the prospective registration. Reporting to the register is based on a paper form including information on the patient (ID, sex, age, American Society of Anesthesiologists classification [ASA], weight and height) surgical date, hospital, diagnosis, pre-operative alignment and grade of osteoarthritis (OA), part and LOT numbers of implants, surgical technique, prophylaxis (antithrombotic and antibiotic) and operating time. Results During the first year (April 2013 to March 2014), 34 clinics reported 220 primary knee osteotomies (209 proximal tibia and 11 distal femur). We estimate that this represents almost 80 % of those performed on the adult population during the period. The majority of the patients were classified as healthy (60 % ASA grade 1), were men (66 %) and the median age was 51 years (range 19–67). Proximal tibia osteotomy for OA performed with open wedge osteotomy using internal fixation without bone transplantation was most commonly reported.
A. W-Dahl (*) : L. Lidgren : M. Sundberg : O. Robertsson Department of Clinical Sciences, Lund, Orthopaedics, Lund University, Box 117, 221 00 Lund, Sweden e-mail: [email protected] A. W-Dahl : L. Lidgren : M. Sundberg : O. Robertsson The Swedish Knee Arthroplasty Register, Skåne University Hospital Lund, Klinikgatan 22, 221 85 Lund, Sweden
Conclusions As relatively few patients are being treated with different types of fixation and bone substitution in Sweden as well as the rapid development of techniques and new implants, a nationwide registration of knee osteotomies is relevant. Keywords Knee osteotomy . Distal femur osteotomy . Proximal tibial osteotomy . National register
Introduction Knee osteotomy is a joint preserving surgery most often used for younger and/or physically active patients with OA. Of the osteotomies performed around the knee joint, high tibial osteotomy (HTO) is absolutely the most common. Most often it is used for medial OA while its use for lateral OA is less common. Osteotomies of the distal femur (DFO) are more infrequent and are used mostly for congenital and acquired deformities as well as sometimes for lateral OA. HTO was introduced in Sweden in 1969 as a standard treatment for uni-compartmental OA by Göran Bauer, a Professor in Lund. However, after the modern knee implants were introduced in the 1970s they quickly became the most common surgical option for OA. Since then the number of osteotomies has constantly diminished. In the beginning of the 1980s, HTO was estimated to constitute about 30 % of the primary knee reconstruction surgery in Sweden [1], decreasing to about 20 % during the period 1989–1991 [2]. A Swedish population-based study of HTOs for OA performed on patients 30 years and older during 1998–2007 showed a further decline by about 30 % [3]. Knee osteotomies can be performed with different methods, such as closed wedge osteotomy, open wedge osteotomy, and dome shaped osteotomy. In the 1980s, closed osteotomy was the standard osteotomy method for OA in
International Orthopaedics (SICOT)
Sweden. However, open wedge osteotomy with external fixation became the most common procedure used during 1998– 2007 as the use of closed wedge osteotomy decreased. The use of open wedge osteotomy has become more popular since the millennium and the use of dome osteotomy has been limited [3]. With relatively few young patients being treated with different methods and techniques that often use different types of fixation and bone substitution, a nationwide registration of knee osteotomies becomes relevant. The choice of method and technique for osteotomy may affect the risk for complications in the short and long term as well as affect a later knee arthroplasty both technically and with respect to longer-term outcome. The health economical perspective is also important for healthcare providers, society and not least the patients. Therefore, a nationwide prospective registration of knee osteotomies, corresponding to the registration of the knee arthroplasty surgery, was started in the spring of 2013.
Materials and methods The inclusion criteria for the prospective national knee osteotomy registration are patients having osteotomy around the knee (distal femur or proximal tibia), primaries as well as re-operations. Reporting to the register is based on a paper form, the same for both primaries and re-operations. The form includes information on patient-ID, hospital, side, date of surgery, diagnosis, type of osteotomy and if other surgeries were performed at the same time as the osteotomy (e.g. arthroscopy or cruciate ligament reconstruction). Information on pre-operative alignment (hip-knee-ankle angle [HKA angle]), radiological grading of osteoarthritis according to the Ahlbäck classification [4] and previous surgery in the index knee are requested. Depending on the surgical technique, information on the use of bone transplantation (patient’s own, bio bank, synthetic), navigation, angulation guide, tourniquet and drainage (yes/no) are requested. In case of open wedge osteoteomy with external fixation the name of the fixator is asked for. Further, the type of anaesthesia, drug prophylaxis (antithrombotic and antibiotic), American Society of Anesthesiologists classification (ASA), weight and height for calculation of body mass index (BMI, kg/m²) and time when the surgery starts (skin incision) and stops (skin closed) is to be reported. For implants (plates, pins, screws or bone substitute), one set of the stickers, found in the implant packages containing the part and lot numbers, are to be placed on the backside of the form. A part-number database has been established and is updated continuously as new implants are reported. It is recommended that the report form is filled out in the operation theatre where all the information needed is available during the surgery. The form is then sent to the register office
where the information is entered into the database. For the reoperations, a copy of the operation report and discharge letter is required. The results of the reported knee osteotomies during the first year (1 April 2013 to 31 March 2014) are presented descriptively. The registration was approved by the Ethics Committee of the Medical Faculty, Lund University (2013/36).
Results During the first year of the registration, from April 1, 2013 to March 31, 2014, a total of 34 clinics reported 220 primary knee osteotomies (Fig. 1). Of them, 209 were osteotomies of the proximal tibia and 11 of the distal femur. Compared to the total number of in-patient knee osteotomies (surgical code NGK 59) in the Patient Administrative Registry (PAR) 2012 of the Swedish National Board of Health and Welfare, which uses the Nordic Medico-Statistical Committee (NOMESCO) Classification of Surgical Procedures (NCSP), this corresponds to 65 % of the osteotomies around the knee irrespective of method, diagnosis or age. However, at present not many osteotomies in children for congenital deformities are reported to the registry and if we limit the comparison to patients older than 15 years of age the register seems to capture around 85 % of the osteotomies on a national level. The response rate of the variables reported on the form was 82–100 %. Of the 34 clinics, 11 clinics reported ten or more osteotomies during the first year. The clinic that reported most, reported 19 osteotomies (Fig. 1). The patients More than half of the patients were classified as healthy (60 % ASA grade 1), they were more often men (66 %), the median age was 51 years (range 19–67) and they had a median BMI of 27 kg/m² (range 20–45). The majority of the patients had OAgrade 1–2 according to the Ahlbäck classification [4] and median preoperative HKA angle was 7°. Patients operated with distal femur osteotomy were younger, most of them women and they had a larger pre-operative malalignment than those operated with proximal tibia osteotomy (Table 1). Osteoarthritis was the dominating indication for surgery (91 %). Other indications were congenital and required deformity, instability and osteonecrosis. The surgeries Open wedge osteotomy was the most commonly used method (87 %) and the technique with internal fixation was used in the majority (68 %). The closed wedge method was used in 7 %
International Orthopaedics (SICOT)
Fig. 1 The number of knee osteotomies and methods in each clinic respectively
Table 1 Patients characteristics Characteristic
All n=220
Age (years) Median 51 Range 19–67 Men/women n 146/74 (%) (34/66) BMI (kg/m²), n (%) (N=204)
ORIGINAL PAPER
Introducing prospective national registration of knee osteotomies. A report from the first year in Sweden Annette W-Dahl & Lars Lidgren & Martin Sundberg & Otto Robertsson
Received: 13 November 2014 / Accepted: 25 November 2014 # SICOT aisbl 2014
Abstract Purpose Knee osteotomy is a joint preserving surgery with new techniques and implants introduced during recent years. However the information of its use and outcome is scarce. A national knee osteotomy register was started in Sweden in 2013 from which we report here the information gathered during the first year of registration. Methods All patients having knee osteotomy (distal femur and proximal tibia), primaries and re-operations are intended to be included in the prospective registration. Reporting to the register is based on a paper form including information on the patient (ID, sex, age, American Society of Anesthesiologists classification [ASA], weight and height) surgical date, hospital, diagnosis, pre-operative alignment and grade of osteoarthritis (OA), part and LOT numbers of implants, surgical technique, prophylaxis (antithrombotic and antibiotic) and operating time. Results During the first year (April 2013 to March 2014), 34 clinics reported 220 primary knee osteotomies (209 proximal tibia and 11 distal femur). We estimate that this represents almost 80 % of those performed on the adult population during the period. The majority of the patients were classified as healthy (60 % ASA grade 1), were men (66 %) and the median age was 51 years (range 19–67). Proximal tibia osteotomy for OA performed with open wedge osteotomy using internal fixation without bone transplantation was most commonly reported.
A. W-Dahl (*) : L. Lidgren : M. Sundberg : O. Robertsson Department of Clinical Sciences, Lund, Orthopaedics, Lund University, Box 117, 221 00 Lund, Sweden e-mail: [email protected] A. W-Dahl : L. Lidgren : M. Sundberg : O. Robertsson The Swedish Knee Arthroplasty Register, Skåne University Hospital Lund, Klinikgatan 22, 221 85 Lund, Sweden
Conclusions As relatively few patients are being treated with different types of fixation and bone substitution in Sweden as well as the rapid development of techniques and new implants, a nationwide registration of knee osteotomies is relevant. Keywords Knee osteotomy . Distal femur osteotomy . Proximal tibial osteotomy . National register
Introduction Knee osteotomy is a joint preserving surgery most often used for younger and/or physically active patients with OA. Of the osteotomies performed around the knee joint, high tibial osteotomy (HTO) is absolutely the most common. Most often it is used for medial OA while its use for lateral OA is less common. Osteotomies of the distal femur (DFO) are more infrequent and are used mostly for congenital and acquired deformities as well as sometimes for lateral OA. HTO was introduced in Sweden in 1969 as a standard treatment for uni-compartmental OA by Göran Bauer, a Professor in Lund. However, after the modern knee implants were introduced in the 1970s they quickly became the most common surgical option for OA. Since then the number of osteotomies has constantly diminished. In the beginning of the 1980s, HTO was estimated to constitute about 30 % of the primary knee reconstruction surgery in Sweden [1], decreasing to about 20 % during the period 1989–1991 [2]. A Swedish population-based study of HTOs for OA performed on patients 30 years and older during 1998–2007 showed a further decline by about 30 % [3]. Knee osteotomies can be performed with different methods, such as closed wedge osteotomy, open wedge osteotomy, and dome shaped osteotomy. In the 1980s, closed osteotomy was the standard osteotomy method for OA in
International Orthopaedics (SICOT)
Sweden. However, open wedge osteotomy with external fixation became the most common procedure used during 1998– 2007 as the use of closed wedge osteotomy decreased. The use of open wedge osteotomy has become more popular since the millennium and the use of dome osteotomy has been limited [3]. With relatively few young patients being treated with different methods and techniques that often use different types of fixation and bone substitution, a nationwide registration of knee osteotomies becomes relevant. The choice of method and technique for osteotomy may affect the risk for complications in the short and long term as well as affect a later knee arthroplasty both technically and with respect to longer-term outcome. The health economical perspective is also important for healthcare providers, society and not least the patients. Therefore, a nationwide prospective registration of knee osteotomies, corresponding to the registration of the knee arthroplasty surgery, was started in the spring of 2013.
Materials and methods The inclusion criteria for the prospective national knee osteotomy registration are patients having osteotomy around the knee (distal femur or proximal tibia), primaries as well as re-operations. Reporting to the register is based on a paper form, the same for both primaries and re-operations. The form includes information on patient-ID, hospital, side, date of surgery, diagnosis, type of osteotomy and if other surgeries were performed at the same time as the osteotomy (e.g. arthroscopy or cruciate ligament reconstruction). Information on pre-operative alignment (hip-knee-ankle angle [HKA angle]), radiological grading of osteoarthritis according to the Ahlbäck classification [4] and previous surgery in the index knee are requested. Depending on the surgical technique, information on the use of bone transplantation (patient’s own, bio bank, synthetic), navigation, angulation guide, tourniquet and drainage (yes/no) are requested. In case of open wedge osteoteomy with external fixation the name of the fixator is asked for. Further, the type of anaesthesia, drug prophylaxis (antithrombotic and antibiotic), American Society of Anesthesiologists classification (ASA), weight and height for calculation of body mass index (BMI, kg/m²) and time when the surgery starts (skin incision) and stops (skin closed) is to be reported. For implants (plates, pins, screws or bone substitute), one set of the stickers, found in the implant packages containing the part and lot numbers, are to be placed on the backside of the form. A part-number database has been established and is updated continuously as new implants are reported. It is recommended that the report form is filled out in the operation theatre where all the information needed is available during the surgery. The form is then sent to the register office
where the information is entered into the database. For the reoperations, a copy of the operation report and discharge letter is required. The results of the reported knee osteotomies during the first year (1 April 2013 to 31 March 2014) are presented descriptively. The registration was approved by the Ethics Committee of the Medical Faculty, Lund University (2013/36).
Results During the first year of the registration, from April 1, 2013 to March 31, 2014, a total of 34 clinics reported 220 primary knee osteotomies (Fig. 1). Of them, 209 were osteotomies of the proximal tibia and 11 of the distal femur. Compared to the total number of in-patient knee osteotomies (surgical code NGK 59) in the Patient Administrative Registry (PAR) 2012 of the Swedish National Board of Health and Welfare, which uses the Nordic Medico-Statistical Committee (NOMESCO) Classification of Surgical Procedures (NCSP), this corresponds to 65 % of the osteotomies around the knee irrespective of method, diagnosis or age. However, at present not many osteotomies in children for congenital deformities are reported to the registry and if we limit the comparison to patients older than 15 years of age the register seems to capture around 85 % of the osteotomies on a national level. The response rate of the variables reported on the form was 82–100 %. Of the 34 clinics, 11 clinics reported ten or more osteotomies during the first year. The clinic that reported most, reported 19 osteotomies (Fig. 1). The patients More than half of the patients were classified as healthy (60 % ASA grade 1), they were more often men (66 %), the median age was 51 years (range 19–67) and they had a median BMI of 27 kg/m² (range 20–45). The majority of the patients had OAgrade 1–2 according to the Ahlbäck classification [4] and median preoperative HKA angle was 7°. Patients operated with distal femur osteotomy were younger, most of them women and they had a larger pre-operative malalignment than those operated with proximal tibia osteotomy (Table 1). Osteoarthritis was the dominating indication for surgery (91 %). Other indications were congenital and required deformity, instability and osteonecrosis. The surgeries Open wedge osteotomy was the most commonly used method (87 %) and the technique with internal fixation was used in the majority (68 %). The closed wedge method was used in 7 %
International Orthopaedics (SICOT)
Fig. 1 The number of knee osteotomies and methods in each clinic respectively
Table 1 Patients characteristics Characteristic
All n=220
Age (years) Median 51 Range 19–67 Men/women n 146/74 (%) (34/66) BMI (kg/m²), n (%) (N=204)
