A majority of surgeons (83%) reported always giving antibiotics on induction when performing K-wire fixation and 33% always prescribe a postoperative course. Most surgeons reported removing exposed K-wires from phalangeal fractures at 4 weeks (60%) and buried wires at 4 weeks (32%) or 6 weeks (28%). For metacarpal fractures, nonburied wires were most often removed at 4 weeks (60%), whereas buried wires were removed at 4 weeks (28%) or 6 weeks (28%). The reported follow-up periods were 6 weeks (17.4%), 8 weeks (20.3%), or 12 weeks (40.1%). Exposed wires were most commonly removed in an outpatient setting, whereas buried wires were most commonly removed in theater (Fig. 1).
Hand therapists mostly had no preference in terms of whether the wire was buried or not (60%). Pin-site infection and osteomyelitis were major concerns for this group. The hand therapists generally rated patient-related outcomes as more important than the clinician group, including quality of life, patient satisfaction, and return to normal activity. Range of movement was also a key outcome of importance for hand therapists, but cosmesis did not score highly in the hand therapy group compared with the clinicians.
Patients in both the buried and exposed wire groups expressed similar concerns (Fig. 2). The primary concerns were related to the K-wire, their recovery, and associated pain. Patients with exposed K-wires were proportionally more concerned about the risk of infection than the other group.
This study used a trainee collaborative approach to assess the current U.K. clinical practice for managing K-wire fixation of metacarpal and phalangeal fractures of the hand. It identified areas of common practice. These included the lack of surgeon preference for K-wire or ORIF for managing hand fractures and the use of antibiotics on induction. It also highlighted areas of clinical variation, including postoperative antibiotic prescribing, location of K-wire removal, and follow-up regimes. The WIRE Study was the first U.K. hand surgery study to take a trainee-led collaborative approach, which has been used with great success in other surgical specialties.15 The survey response rates were markedly higher than a comparable study from our network investigating preferences for managing mallet finger injuries.16 The collaborative model improved survey methodology through collection of denominator lists and by directly engaging clinicians and patients when completing the survey.
Half of the surgeons expressed a preference for burying K-wires with the other half either having no preference or reporting a preference for leaving wires exposed. This uncertainty reflects the clinical equipoise and low-quality evidence available to inform decision-making.12 Risk of infection was identified as an independent variable in the decision making of those surgeons preferring to bury wires. Infection was also a major concern of patients. However, infection rates are reported to be low in other studies, and it is unclear whether burying K-wires reduces infection rates in the hand. A recent retrospective case review of 695 patients with buried and exposed K-wires in hand and wrist fractures found that exposed K-wires were more likely to be treated for a pin-site infection than buried wires. Exposed K-wires in metacarpal fractures were the most likely to require antibiotic treatment.17 Another recent retrospective series of 1,213 patients, with K-wires left exposed following fixation of hand and wrist fractures, reported that 85 (7%) developed a pin-site infection.18 Five (0.4%) of these patients required further surgery, 3 for osteomyelitis. The rest were successfully treated with antibiotics. Botte et al.19 reported an infection rate of 7% in a series of 137 patients with exposed K-wire fixation of hand fractures. Koç et al.7 reported infection rates of 10% in exposed and 9% in buried K-wires when used in hand fracture fixation. A number of studies use the Oppenheim Classification of pin-site infection, or a modification. It remains unclear whether a pin-site infection has any long-term effect on patient outcomes.
Ease of wire removal was an independent variable in the decision making of those surgeons preferring to leave wires exposed. Removal of buried wires usually requires admission to hospital for a further procedure. This is inconvenient and costly for both patient and health service. A U.K.-based cost-analysis by Koç et al.7 of metacarpal and phalangeal fractures reported a cost per patient of £235.51 and £90.80 for buried wires and exposed wires, respectively. Despite this clear cost difference, surgeons in this study did not score economic factors as being important in the decision-making process.
The survey identified a trend toward surgical factors determining the choice to bury or leave K-wires exposed. This included risk of pin-site infection, osteomyelitis, range of motion, and grip strength. Patient-related outcomes including the Disabilities of the Arm, Shoulder and Hand scores, cosmesis, quality of life, return to normal function, and postoperative pain did not seem to have any significant impact on the decision-making process. In contrast to the surgeon responses, hand therapists’ responses highlighted their interest in the impact on patient satisfaction and quality of life.
Limitations of the study include the geographical restriction to the United Kingdom. The “event rate,” which in this case was the preference to bury K-wires, was lower than had been anticipated. Convention suggests that studies should have 10 events per covariate; the regression analysis performed in the present study might be considered underpowered.20 However, the validity of this heuristic has been challenged, and lower event rate:covariate ratios may be acceptable.21 The other option would have been to only analyze a restricted number of covariates, or to generate a parsimonious set using stepwise methods. Neither of these options were considered appropriate for an exploratory study. Instead, the potential for under powering and over fitting in this study was accepted. Our ordinal scales of variables were treated as covariates in the regression analysis rather than as factors, despite not having interval-level measurement properties demonstrated. In the absence of clear a priori hypotheses about cutoffs in the scales, and a desire to avoid exacerbating potential under powering, this was considered reasonable.
This trainee-led, collaborative national survey of clinicians and patients has identified key areas of clinical variability and uncertainty in the management of patients undergoing K-wire fixation of hand fractures. Decisions to bury or leave K-wires exposed are based on surgical dogma rather than evidence. Surgeon-centric factors seem to outweigh patient center factors in the decision-making process. Our findings along with further public and patient engagement, funded by the British Association of Plastic, Reconstructive and Aesthetic Surgeons, will be used to develop a protocol for a randomized clinical trial.
SG, FI, MDG, HLH, JCRW and AJ conceived the idea; SG, HLH, JCRW, MDG, FI, TP, JNR and AJ formed the steering group and were involved in every aspect of patient and public engagement, protocol design and delivery of the project; SG and MDG programmed REDCap; JNR performed the statistical analysis; JCRW and MDG drafted the manuscript, all members of the steering group revised the manuscript and act as guarantors. WIRE Collaborators produced the denominator lists, ensured surgeons and therapists completed the surveys and identified patients to survey.
The Steering Group acknowledges the following contributors: Ben Dean, Lewis Dingle, Roisin Dolan, Shakeel Dustagheer, Jessica Harvey, Alex Reid, Andrew Robinson, Daniel Ryan, and thank the following units for participating in the study: Addenbrooke’s Hospital, Arrowe Park Hospital, Bradford Royal Infirmary, Broomfield Hospital, Cardiff University Hospital Wales, Chelsea and Westminster Hospital, Derriford Hospital, Glasgow Royal Infirmary, Gloucester Royal Hospital, Hull Royal Infirmary/Castle Hill Hospital, James Cook University Hospital, John Radcliffe Hospital, Leeds General Infirmary, Leicester Royal Infirmary, Lincoln County Hospital, Mater Misercordiae, Morriston Hospital, New Pinderfields Hospital, Norfolk and Norwich University Hospital, Peterborough City Hospital, Pulvertaft Hand Centre, Queen Alexandra Hospital, Queen Elizabeth Hospital, Queen Victoria Hospital, Queen’s Medical Centre, Royal Berkshire Hospital, Royal Devon and Exeter Hospital, Royal Free Hospital, Royal Preston Hospital, Royal Stoke Hospital, Royal Victoria Infirmary, Salisbury District Hospital, Southampton General Hospital, Southmead Hospital, St George’s Hospital, St. James’s Hospital, St John’s Hospital at Howden, St Mary’s Hospital, St Thomas’ Hospital, Stoke Mandeville Hospital, The Countess of Chester Hospital, Ulster Hospital, The Robert Jones and Agnes Hunt Orthopaedic Hospital, The Lister hospital, University Hospital Coventry, Wexham Park Hospital, Whiston Hospital.
1. Karl JW, Olson PR, Rosenwasser MP. The epidemiology of upper extremity fractures in the United States, 2009. J Orthop Trauma. 2015;29:242–244.
2. Anakwe RE, Aitken SA, Cowie JG, et al. The epidemiology of fractures of the hand and the influence of social deprivation. J Hand Surg Eur Vol. 2011;36:62–65.
3. Bucholz RW. Chapter 3. The epidemiology of fractures. Rockwood and Green’s Fractures in Adults. 2009.Vol 1. 7th ed. Philadelphia: Lippincott Williams & Wilkins.
4. van Onselen EB, Karim RB, Hage JJ, et al. Prevalence and distribution of hand fractures. J Hand Surg Br. 2003;28:491–495.
5. Diaz-Garcia R, Waljee JF. Current management of metacarpal fractures. Hand Clin. 2013;29:507–518.
7. Koç T, Ahmed J, Aleksyeyenko S. Buried Kirschner wires in hand trauma: do they reduce infection rates and is it worth the extra cost? Eur J Plast Surg. 2012;35:803–807.
8. Cheng HS, Wong LY, Chiang LF, et al. Comparison of methods of skeletal fixation for severely injured digits. Hand Surg. 2004;9:63–69.
9. Hsu LP, Schwartz EG, Kalainov DM, et al. Complications of K-wire fixation in procedures involving the hand and wrist. J Hand Surg Am. 2011;36:610–616.
10. Hargreaves DG, Drew SJ, Eckersley R. Kirschner wire pin tract infection rates: a randomized controlled trial between percutaneous and buried wires. J Hand Surg Br. 2004;29:374–376.
11. Das De S, Bae DS, Waters PM. Displaced humeral lateral condyle fractures in children: should we bury the pins? J Pediatr Orthop. 2012;32:573–578.
12. Wormald JCR, Jain A, Lloyd-Hughes H, Gardiner S, et al. A systematic review of the influence of burying or not burying Kirschner wires on infection rates following fixation of upper extremity fractures. J Plast Reconstr Aesthet Surg. 2017; 70 (9): 1298–1301.
13. Harris PA, Taylor R, Thielke R, et al. Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42:377–381.
14. Benjamini Y, Hochberg Y. Controlling the false discovery rate: a practical and powerful approach to multiple testing. J R Stat Soc Series B. 1995;57(1):289–300.
15. Bhangu A, Kolias AG, Pinkney T, et al. Surgical research collaboratives in the UK. Lancet. 2013;382:1091–1092.
16. Tolkien Z, Potter S, Burr N, et al. Conservative management of mallet injuries: a national survey of current practice in the UK. J Plast Reconstr Aesthet Surg. 2017;70:901–907. doi: 10.1016/j.bjps.2017.04.009. [Epub ahead of print].
17. Ridley TJ, Freking W, Erickson LO, et al. Incidence of treatment for infection of buried versus exposed Kirschner wires in phalangeal, metacarpal, and distal radial fractures. J Hand Surg Eur Vol. 2017;42:525–531. doi: 10.1016/j.jhsa.2017.03.040. [Epub ahead of print].
18. van Leeuwen WF, van Hoorn BT, Chen N, et al. Kirschner wire pin site infection in hand and wrist fractures: incidence rate and risk factors. J Hand Surg Eur Vol. 2016;41:990–994.
19. Botte MJ, Davis JL, Rose BA, et al. Complications of smooth pin fixation of fractures and dislocations in the hand and wrist. Clin Orthop Relat Res. 1992:194–201.
20. Peduzzi P, Concato J, Kemper E, et al. A simulation study of the number of events per variable in logistic regression analysis. J Clin Epidemiol. 1996;49:1373–1379.
21. Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol. 2007;165:710–718.
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