Abstract

Abstract

‘Primum non nocere’ is one of the most well known moral principles associated with the medical profession. Often, in our bid to maintain and improve quality of life, we neglect to recognise those patients who are in fact nearing the end of theirs. Thus, our aim was to ascertain if we are recognising the ‘dying’ orthopaedic patient and whether key elements of management in accordance with SIGN are being addressed.

All hip-fracture deaths occurring at a District General Hospital over a 4-year period (2012–2015) were included. Paper and electronic notes were used to record patient demographics, days from admission to death, diagnosis of ‘dying’ and discussions regarding DNACPR and ceiling of care. Total numbers of investigations undertaken during the week prior to death were noted.

89 hip-fracture deaths occurred between 2012–2015, of which 57 were female with a mean age at death of 84 years. The number of days post-admission to death was 17.5 (range 0–109). 45 patients had a new DNACPR recorded and 13 were longstanding. 43 patients (48.3%) were diagnosed as dying at a mean of 7.2 days following admission, 31 of whom (72.1%) had ceiling of care discussed. Of this cohort, 32 had futile investigations during their last week of life and astoundingly 10 on the day of death.

Although some effort is being made to recognise the ‘dying’ orthopaedic patient, further work is needed to establish a clear ceiling of care pathway, which maintains and respects patient comfort and dignity during their last days of life.

We describe the association between post-operative femoral stem radiological appearances and aseptic failure of THA (total hip arthroplasty) following a retrospective review of records and radiographs of all patients attending for follow-up between August 2002 and August 2003 who had a cemented Charnley femoral stem and either a cemented polyethylene acetabular cup inserted. Femoral stem aseptic loosening was defined either by findings at revision surgery, the definite radiographic loosening criteria of Harris or progressive endosteal cavitation across zones as described by Gruen. Well-fixed control THAs were defined as those that demonstrated none of the radiographic features of aseptic loosening or ‘at risk’ signs as described by Wroblewski. Parameters measured were: Alignment, Barrack grade of cementation, cement mantle width of the cement mantle and the presence and width of any radiolucent lines.

Sixty-three hips were entered into the aseptic failure group and 138 into the control group. The alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was statistically associated with failure in Gruen zones 6 (p=0.040) and Gruen zone 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). The grade of cementation as measured by the Barrack grade was strongly associated with failure for grades C (p=0.001) and D (p=0.001).

This study has demonstrated that easily applied radiological criteria can be used to identify ‘at risk’ Charnley THAs from the immediate post-operative AP radiograph.

The Osteoprotegerin/RANK/RANKL system has been implicated in the biological cascade of events initiated by particulate wear debris and bacterial infection resulting in periprosthetic bone loss around loosened total hip arthroplasties (THA). Individual responses to such stimuli may be dictated by genetic variation and we have studied the effect of single nucleotide polymorphisms (SNPs) within these genes.

We performed a case control study of the Osteoprotegerin, RANK and RANKL genes for possible association with deep sepsis or aseptic loosening. All patients included in the study were Caucasian and had had a cemented Charnley THA and polyethylene acetabular cup. Cases consisted of 91 patients with early aseptic loosening and 71 patients with microbiological evidence at surgery of deep infection. Controls consisted of 150 THAs that were clinically asymptomatic for over 10 years and demonstrated no radiographic features of aseptic loosening. DNA samples from all individuals were genotyped using Taqman allelic discrimination.

The A allele (p<0.001) and homozygous genotype A/A (p<0.001) for the OPG-163 SNP were highly associated with aseptic failure. Additionally, the RANK-575 (C/T SNP) T allele (p=0.004) and T/T genotype (p=0.008) frequencies were associated with aseptic failure. No statistically significant relationship was found between aseptic loosening and the OPG- 245 or OPG-1181 SNPs.

When the septic group was compared to controls, the frequency of the A allele (p<0.001) and homozygous genotype A/A (p<0.001) for the OPG-163 SNP were statistically significant. No statistically significant relationship was found between septic failure and the OPG- 245, OPG-1181 or RANK-575 SNPs.

Aseptic loosening and possibly deep infection of THA may be under genetic influence to candidate susceptibility genes. SNP markers may serve as predictors of implant survival and aid pharmacogenomic prevention of THA failure.

Introduction: Ilizarov frames are widely used as an external fixation system. Whether applied for trauma, bone transport or deformity-correction they are usually applied for a minimum of three months and can be used for over a year. The psychological and lifestyle impact of frames has been shown to be significant.

Purpose: We examined the informational needs of patients with Ilizarov frames pre and post-operatively. We then assessed how these needs are met by the provision of a nurse-led support group.

Methods: All patients with Ilizarov frames applied at Hope Hospital, Manchester were contacted by postal questionnaire. Questions were asked about preparation before surgery, changes to lifestyle and information received. Specific questions were asked about attendance at the nurse-led Ilizarov support group.

Results: Thirty-seven patients replied. Twenty-two had frames on and fifteen had recently had them removed. Most patients reported feeling well prepared before surgery regarding the likely impact on their lives. Two-thirds (twenty-five) felt they had received adequate information. Three-quarters (twenty-six) patients had attended the Ilizarov support group and most (twenty-one) had attended the group pre¬operatively. Over three-quarters of patients agreed they would attend the group with a “frame problem” before attending their own GP. All patients found the group supportive and felt comfortable discussing their problems.

Conclusion: The Ilizarov Support Group is a useful resource for people with frames. The group atmosphere is supportive to patients and it is a valuable problem-solving environment. It helps patients prepare for their surgery and reduces attendance to primary care providers for frame related problems. We suggest other Ilizarov units may benefit from the provision of such a service.

Total hip replacement is a successful and reliable procedure for the relief of pain, but the results achieved have been reported to be less successful in younger patients who tend to be relatively more active and place greater demands on prostheses than older patients.

Between 1966 and 1978, 226 Charnley low friction arthroplasties (LFAs) were implanted in young patients with an average age at operation of 31.7 years. Initial results were presented at an average of 19.7 years. We have performed a further retrospective analysis of this cohort at 10 years on from the time of data collection of the original study. Of the original cohort, 112 patients are alive and either under follow-up at our hospital or have been traced to other hospitals. 16 have been lost to follow-up. Mean follow-up was 26.4 years. At the time of final follow-up or death, rate of aseptic loosening of the stem was approximately 80%. Acetabular components proved to be less successful with less than 60% remaining well fixed. Differences in survival were apparent between subgroups with differing original pathology with stem survival greater in those with DDH as opposed to rheumatoid or degenerative arthritis and the opposite being true for socket survival.

This study adds to the available knowledge of the longevity of cemented total hip replacement as performed with unsophisticated cementation techniques and how it may perform in differing patients groups.

A secure bone cement interface between the acetabulum and the cement mantle of the hip socket is an important requirement for the long-term success of a cemented hip arthroplasty. Cement pressurisation after bone bed cleaning enables cement to penetrate interstices of cancellous bone forming a superior fixation strength.

We designed an in-vitro experiment to evaluate the performance of the Exeter, Depuy T-handle and a plunger-type pressurisers using two parameters: cement penetration and cement pressurisation.

The deformation of the flexible pressure head of the DePuy model produced a cement mantle, which is thick at the pole but tapered at its rim and variable in the amount of penetration produced (range 2–8mm) for an estimated similar force. Pressures of up to 60KPa were generated throughout the model acetabulum. The Exeter pressuriser was found to produce cement mantles more compatible with a socket. However, the test results show a wide variation in cement penetration occurring for what was estimated to be a similar applied force (3mm to 9mm at the pole and 5mm to 9mm at the rim). It was also shown to have the disadvantage of causing widely dissimilar pressures at the pole and the rim. The plunger protrusion required to produce 5mm cement penetration was found to be 7.5mm. Since this protrusion can be monitored and controlled by the operator, a cement intrusion of 5mm +/−1mm was found to be reproducible with the plunger-type device. The maximum variation in intrusion between rim and pole was 1 mm. Maximin pressures of 70KPa were generated.

We have presented experimental evidence that suggests that a plunger type of acetabular cement pressuriser may provide a more consistently reproducible level of pressurisation leading to optimal cement penetration.

Introduction: In attempting to unravel the complex cellular responses leading to prosthetic loosening investigators have been limited to studying gene expression of extracellular molecules about which most is known whereas new microarray technology allows simultaneous expression profiling of thousands of genes from a complex sample such as the membrane formed around loosened hip prostheses.

Methods: Two groups of 8 patients were recruited who have undergone primary total hip arthroplasty for osteoarthritis and subsequently developed either septic or aseptic loosening +/− osteolysis. The control group consisted of one group of 5 patients with the same initial diagnosis who had undergone identical procedures, developed no clinical or radiological signs of aseptic or septic loosening, but had come to revision surgery for other complications as defined by the Swedish Hip register: fracture without previous osteolysis, dislocation, technical error, implant fracture, polyethylene wear or pain. Periprosthetic membrane was harvested at the time of revision surgery and subjected to RNA extraction. cDNA was then synthesized and hybridised to a Human Genome u95 Genechip ® array which contains a complete set of known human genes. Data normalisation, data filtering and pattern identification was performed using Genechip®3.1 software (Affymetrix, Santa Clara, CA).

Results: This has revealed the involvement of a large number of genes coding for transcriptional regulators upstream from the extracellular and cell-cell signalling molecules already known to be involved in osteolysis and deep infection and which may ultimately control the responses to wear particles and bacterial challenge. Differential expression of genes involved in cell survival and death, cell growth regulation, cell metabolism, inflammation and immune response was found. Most interestingly pathways for control of local bone resorption and inflammatory response have been shown to be highly activated.

Conclusions: The identification of these new pathogenetic mechanisms of total hip replacement failure make new indicators of disease susceptibility and prognosis plus new drug targets direct possibilities.

Introduction: Our group has previously reported on microarray gene expression profiling of failed aseptic and septic THRs. The data obtained from the Affymetrix DNA chips suggested a range of 21 differentially expressed genes between the tissue samples obtained from the control and study patients with failed aseptic THRs. The variation in expression that was demonstrated did not suggest that the basis of the local tissue reaction that occurs in aseptic loosening of THR is primarily inflammatory in nature. In order to validate these results we have performed quantitative real-time polymerase chain reaction (RT-PCR) to analyse the transcriptional levels of genes expression in the samples used in our original study and to formulate a hypothesis of how these candidate genes can be related to aseptic join loosening.

Methods: 3 control and 6 aseptic samples of peri-prosthetic membrane were subjected to RNA extraction. RNA quality analysis and quantification were performed. SYBRâ Green I real time quantitative PCR (RT qPCR) assays were designed using Primer Express [Applied Biosystems] and BLAST searching the resulting sequences. The comparative method for quantitation of gene expression levels, which utilizes arithmetic formulas to give the similar results to those achieved with standard curves, was utilised to validate the cDNA microarray data.

Results: We were able to devise successful quantitative real-time PCR for 15 of the 21 candidate genes plus the reference gene GAPDH. The genes coding for complement component C4B, Osteonectin , ATP2A2 (an ATPase linked to the regulation of adhesion, differentiation and proliferation in tissue that expresses this gene such as bone) and Phospholipase2A, were all found to be under-expressed whereas SLC2A5 (a solute carrier that can facilitate glucose/fructose transport)and NPC1 (intimately involved in cholesterol and glycolipid trafficking and inversely related to PLA2-mediated release of eicosanoids such as PGE2) were found to be over-expressed.

Conclusions: The data from our gene expression and RT-PCR studies have suggested novel pathways that may be intimately involved in the development of peri-prosthetic osteolysis and aseptic loosening that are distinctly different from the currently accepted theory of a proinflammatory cytokine cascade initiated by tissue reaction to particulate wear debris. These include possible alteration in both extra- and intracellular Ca2+ metabolism together with a possible effect upon extra-cellular matrix function. Altered lipid metabolism may also be evident and in particular decreased eicosanoid production. Intriguingly, the pattern of gene expression that is seen our studies would appear to be quite different than that seen in synovial inflammatory arthritidies such as rheumatoid and osteo-arthritis and suggests that previous studies that has used these pathological mechanisms as comparisons or controls may be flawed.

Introduction: We describe the association between postoperative femoral stem radiological appearances and aseptic failure of THA (total hip arthroplasty).

Methods: A retrospective review of records and radiographs of all patients attending for follow-up between August 2002 and August 2003 who had a cemented Charnley femoral stem and either a cemented polyethylene acetabular cup inserted. Femoral stem aseptic loosening was defined either by findings at revision surgery, the definite radiographic loosening criteria of Harris or progressive endosteal cavitation across zones as described by Gruen. Well-fixed control THA’s were defined as those that demonstrated none of the radiographic features of aseptic loosening or ‘at risk’ signs as described by Wroblewski. Parameters measured were: Alignment, Barrack grade of cementation, cement mantle width of the cement mantle and the presence and width of any radiolucent lines

Results: 63 hips were entered into the aseptic failure group and 138 into the control group. The alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was statistically associated with failure in Gruen zones 6 (p=0.040) and Gruen zone 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). The grade of cementation as measured by the Barrack grade was strongly associated with failure for grades C (p=0.001) and D (p=0.001).

Discussion and conclusion: This study has demonstrated that easily applied radiological criteria can be used to identify ‘at risk’ Charnley THA’s from the immediate post-operative AP radiograph.

Previous attempts to assess the comfort and protection afforded by surgical gowns have been extremely simplistic and limited in their nature relying on a single and subjective linear scoring system. We have performed a comfort assessment comparison between the Charnley exhaust suit, disposable gown plus visor and the Stryker Steri-Shield system using a newly developed objective multi-dimensional validated ergonomic tool.

A prospective, comparative study was conducted using a modification of the Comfort Rating Scales (CRS) designed to measure wearable comfort of computer devices during physical activity across 6 dimensions. These dimensions are emotion, attachment, harm, perceived change, movement and anxiety.

10 theatre staff were recruited to the study and completed modified CRS scores on three separate occasions after having worn a disposable surgical gown plus mask with visor, a Charnley exhaust suit and a Stryker Steri-Shield system. The total mean CRS for a disposable gown plus visor was 16.1 with a mean dimensional score of 2.7 (range: 0.2 – 8.4), for the Charnley system the values were 51.4 and 8.6 (range: 5.9 – 12.8) respectively and for the Stryker Steri-Shield 15.4 and 2.6 (range: 0.8–5.6).

Although disposable, impermeable gown plus visor or the Steri-Shield system provide a similar level of comfort, the modified CRS has demonstrated that over 6 dimensions of measurable comfort the Steri-Shield system provides the least variation in comfort and as such may offer the best combination of comfort, protective qualities and form or style of personal protection systems for lower limb arthroplasty operations.

Introduction: Non-steroidal anti-inflammatory drugs (NSAIDs) are inhibitors of cyclooxygenase activity and are potential therapeutic agents in the prevention of aseptic loosening. Cigarette smoking is a risk factor for decreased proximal femur bone density. We investigated whether the clinical variables of NSAID usage and cigarette smoking are possibly linked to aseptic loosening around total hip arthroplasty (THA).

Methods: Retrospective review of records and radiographs of all patients attending for follow-up between August 2002 and 2003 who had undergone THA. Age, gender, primary and revision surgery details, radiographic parameters as detailed above, smoking history and NSAID usage history were recorded. Logistic regression analysis was used to determine the presence of associations.

Results: 224 patients were recruited to the study: 143 to the control group with a mean time of THR survival of 14.6 years and 81 to the aseptic group with a mean time to THR failure of 5.1 years. 130 patients had never smoked, 69 were ex-smokers and 25 were smokers (average of 15.5 cigarettes/day). 13.6% of patients in the study group were smokers and 10.5% in the control group. The average duration of NSAID usage pre-operatively was 3.4 years and post-operatively was 4.4 years. Using the logistic regression model, amount of cigarettes smoked, years as a non-smoker and length of usage of NSAID were not found to be associated with aseptic loosening

Discussion and conclusions: We found no such statistically significant relationship with regards to smoking habit or NSAID usage as either protective or risk factors.

Aims: Tumour necrosis factor-alpha is a proinflammatory cytokine that has been implicated in the inflammatory response to bacterial infection and wear debris particles around loosened total hip replacements (THR). Individual TNF responses to such stimuli may be dictated by genetic variation and we have studied the effect of single nucleotide polymorphisms (SNPs) within the TNF gene.

Methods: We performed a case control study of 9 SNPs (−1031, −863, −857, −376, −308, −238, +489, +851 and +1304) for possible association with deep sepsis or aseptic loosening. All patients included in the study were Caucasian and had had a cemented Charnley THR. Cases consisted of 44 patients with early aseptic loosening and 30 patients with microbiological evidence at surgery of deep infection. Controls consisted of 85 THRs that were clinically asymptomatic for over 10 years and demonstrated no radiographic features of aseptic loosening. DNA was extracted from venous blood and genotyped by Snapshot assay.

Results: Genotype and allele frequencies for all SNPs were in Hardy-Weinberg equilibrium between THR controls and a random sample of UK Caucasians. A significant association was found for the -863 SNP and aseptic loosening (p< 0.05; OR=2.36; 95% CI: 0.976 – 5.71). A trend towards association was found between the -863A SNP and deep infection (p=0.80; OR=2.42; CI: 0.800 – 7.34).

Conclusions: Genetic polymorphism of TNF-alpha may play a significant role in THR aseptic loosening and possibly in deep infection. SNP markers may serve as predictors of implant survival and response to therapy such as anti-TNF treatment.

In 1999 a statement of best practice in primary total hip replacement was approved by the Council of the British Orthopaedic Association (BOA) and by the British Association for Surgery of the Knee (BASK) to provide a basis for regional and national auditable standards: we have compared practice in the North West of England to this document to ascertain adherence to this guide to best practice.

A direct comparison of data held on the North West Hip Arthroplasty Register for 2001/2002 and BASK/BOA guidelines was performed. 86 surgeons from 26 hospitals were included in the study. A mean of 93.3% of operations were performed in the surgeon’s usual theatre. All of these theatres had vertical laminar air flow systems. 42.2% of respondents routinely used exhaust suits. 68.1% of respondents routinely used impermeable disposable gowns. All surgeons use some form of anti-thromboembolic prophylaxis. 66.2% use a combination of both mechanical and chemical means. All surgeons used antibiotic prophylaxis. The most popular choice of antibiotic was a cephalosporin. 93.7% of surgeons routinely use antibiotic-loaded cement. The PFC and Kinemax prostheses were the most commonly used pros-theses. Interestingly, 97.7% of all first choice implants were cemented. Only 2 surgeons used uncemented TKR. 69.8% of surgeons used a posterior cruciate retaining design. A midline longitudinal skin incision is used by 87.2% of surgeons, a medial longitudinal skin incision by 7.0% and a lateral longitudinal skin incision by 5.8% 0f surgeons. A medial parapatellar capsular incision is preferred by 91.9% with the remainder using mid vastus or trivector retaining capsulotomy. Closure of capsulotomies is performed in flexion by 65.1% and in extension by 34.9%. In patients with osteoarthritis 38.4% routinely resurfaced the patella, 34.9% never resurfaced the patella and 26.7% selectively resurfaced. This was in direct contrast to practice for patients with rheumatoid arthritis in whom 66.3% routinely resurfaced the patella, 22.1% never resurfaced the patella and 11.6% selectively resurfaced.

This study has demonstrated considerable variation of practice in hip arthroplasty across the North West region and significant divergence from the BASK/BOA statement of best practice. The introduction of a properly funded national arthroplasty register will surely help to clarify the effect of such diverse practice on patient outcome.

Introduction and aims: Numerous questionnaires are available to assess outcome of hip arthroplasty, but as yet there is no consensus as to which are the most appropriate to use following acetabular osteotomy. We have prospectively evaluated a quality of life measure validated for patients from the United Kingdom and self-administered disease and hip specific questionnaires in patients undergoing Bernese periacetabular osteotomy and compared these to outcome as measured by the Harris hip and Merle d’Aubigne and Postel hip scores.

Method: Since 1997, 24 Bernese periacetabular osteotomies have been performed at our institution. Only patients with a primary diagnosis of development dysplasia of the acetabulum, no evidence of degenerative disease and a minimum of 24 months of follow-up were included in this study. Any non life-threatening co-morbid conditions were documented and recorded. Harris hip (HHS), Merle d’Aubigne and Postel (MDP), Nottingham Health Profile (NHP) and Oxford Hip scores (OHS) were calculated pre-operatively and post-operatively at 6 weeks, 12 weeks, 6 months, one year and then yearly.

Results: Patients have been followed up for an average of 3.2 years (range: 1–5.5 years). The male: female ratio was 1: 8.5. The average age at time of operation was 32.3 years (range 18 – 48). No patient required further surgery or conversion to total hip arthroplasty. Mean postoperative HHS was 89.9. MDP 16.4 and OHS 16.3. All dimensions of the NHP demonstrated improvement of greater than 50 %. The MDP and OHS were most sensitive to time of assessment in the post-operative period. There was no significant difference in the order of magnitude of improvement between any of the scores.

Conclusion: This study has demonstrated that the Bernese periacetabular osteotomy, in a carefully selected group of patients, has a reproducibly good outcome as measured by a variety of scoring methods dependent upon both clinician and patient derived assessment.

Purpose: In attempting to unravel the complex cellular responses leading to prosthetic loosening investigators have been limited to studying gene expression of extracellular molecules about which most is known whereas new microarray technology allows simultaneous expression profiling of thousands of genes from a complex sample such as the membrane formed around loosened hip prostheses.

Methods: Two groups of 8 patients were recruited who have undergone primary total hip arthroplasty for osteoarthritis and subsequently developed either septic or aseptic loosening +/− osteolysis. The control group consisted of one group of 5 patients with the same initial diagnosis who had undergone identical procedures, developed no clinical or radiological signs of aseptic or septic loosening, but had come to revision surgery for other complications as defined by the Swedish Hip register: fracture without previous osteolysis, dislocation, technical error, implant fracture, polyethylene wear or pain. Peri-prosthetic membrane was harvested at the time of revision surgery and subjected to RNA extraction. cDNA was then synthesized and hybridised to a Human Genome u95 Genechip ® array which contains a complete set of known human genes. Data normalisation, data filtering and pattern identification was performed using Genechip®3.1 software (Affymetrix, Santa Clara, CA).

Results: This has revealed the involvement of a large number of genes coding for transcriptional regulators upstream from the extracellular and cell-cell signalling molecules already known to be involved in osteolysis and deep infection and which may ultimately control the responses to wear particles and bacterial challenge. Differential expression of genes involved in cell survival and death, cell growth regulation, cell metabolism, inflammation and immune response was found. Most interestingly pathways for control of local bone resorption and inflammatory response have been shown to be highly activated.

Conclusions: The identification of these new pathogenetic mechanisms of total hip replacement failure make new indicators of disease susceptibility and prognosis plus new drug targets direct possibilities.

Injuries to the lower urinary tract are well recognized following fractures to the pelvic ring. The overall incidence of pelvic fractures is similar in men and women. However associated urological injuries occur less frequently in women. There are very few reported cases of combined bladder and urethral injury or combined intra- and extraperitoneal bladder rupture in women. Only two cases have been reported describing communication of the hip joint and an extra peritoneal bladder rupture.

To our knowledge we are the first to describe a pelvic ring injury complicated by combined intra and extra-peritoneal bladder rupture, urethral injury and direct intraperitoneal communication of the ruptured bladder with a central dislocation of the hip joint. The mechanism of bladder laceration was gross displacement of the quadrilateral plate and pubic rami following acetabular fracture. This bone was found at laparotomy to be lying within the bladder cavity.

To determine the type and number of injuries that occur during the training and practice of Muay Thai kick boxing and to compare the data obtained with those from previous studies of karate and taekwondo.

One to one interviews using a standard questionnaire on injuries incurred during training and practice of Muay Thai kick boxing were conducted at various gyms and competitions in the United Kingdom and a Muay Thai gala in Holland.

A total of 152 people were questioned, 132 men and 20 women. There were 19 beginners, 82 amateurs, and 51 professionals. Injuries to the lower extremities were the most common in all groups. Head injuries were the second most common in professionals and amateurs. Trunk injuries were the next most common in beginners. The difference in injury distribution among the three groups was significant (p≤0.01). Soft tissue trauma was the most common type of injury in the three groups. Fractures were the second most common in professionals, and in amateurs and beginners it was sprains and strains (p≤0.05). Annual injury rates were: beginners, 13.5/1000 participants; amateurs, 2.43/1000 participants; professionals, 2.79/1000 participants. For beginners, 7% of injuries resulted in seven or more days off training; for amateurs and professionals, these values were 4% and 5.8% respectively. The results are similar to those found for karate and taekwondo with regard to injury distribution, type, and rate. The percentage of injuries resulting in time off training is less.