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A comparison of nonoperative vs. Endobutton repair of distal biceps ruptures
J Shoulder Elbow Surg (2016) 25, 341–348
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A comparison of nonoperative vs. Endobutton repair of distal biceps ruptures Andrew J. Legg, FRCS (Orth)*, Richard Stevens, MRCS, Nanette O. Oakes, BSc, Shantanu A. Shahane, FRCS (Orth) Chesterfield Royal Hospital, Chesterfield, Derbyshire, UK Background: The aim of this study was to compare the outcome of patients who have undergone distal biceps tendon repair by a single-incision Endobutton fixation technique with the results of another cohort of patients who elected not to undergo surgery for distal biceps tendon rupture. Methods: A retrospective cohort study was performed of patients diagnosed with distal biceps ruptures, repaired with an Endobutton (Smith & Nephew, Andover, MA, USA) technique or treated nonoperatively by the senior surgeon (S.A.S.). With a minimum follow-up of 6 months, a routine elbow examination, radiographs, and functional questionnaires were performed. Isometric supination, flexion, and grip strength was measured using a BTE machine (Baltimore Therapeutic Equipment, Hanover, MD, USA). There were 47 patients available for follow-up with 50 distal biceps ruptures; 40 ruptures have undergone repair, and 10 have been managed nonoperatively. Three patients had sustained bilateral ruptures. Results: There was a significant difference in flexion and supination isometric strength between the operative and nonoperative cohorts compared with the uninjured contralateral side (92.94% vs. 70.65%, P = .01512; 87.91% vs 59.11%, P = .00414, respectively). The difference in grip strengths between the 2 cohorts compared with the uninjured side was not significant (100.00% vs. 79.16%; P = .16002). The operated cohort had significantly better QuickDASH score, Oxford Elbow Score, and Mayo Elbow Performance Score (6.29 vs. 14.10, P = .02123; 44.71 vs. 38.70, P = .00429; 93.13 vs. 84.50, P = .01423). Conclusion: Repair of distal biceps ruptures using an Endobutton fixation results in nearly normal return of strength and function, which is significantly better than in those managed nonoperatively. Level of evidence: Level III, Retrospective Cohort Design; Treatment Study © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees Keywords: Biceps; Endobutton; distal; repair; tendon; rupture
Starks reported the first distal biceps tendon rupture in 1843. More than 50 years later in 1897, Johnson reported repair of Ethics approval was gained from the NRES Committee East Midlands— Nottingham 1 (REC reference 13/EM/0053). *Reprint requests: Andrew J. Legg, FRCS (Orth), 6 Edmonton Place, Chapel Allerton, Leeds, West Yorkshire LS7 4LP, UK. E-mail address: [email protected] (A.J. Legg).
the distal biceps tendon using a single anterior incision approach.14,16 The majority of biceps tendon ruptures involve the long head proximally or, more infrequently, the short head; only 3% of all biceps tendon ruptures occur in the distal biceps tendon.2 Distal biceps ruptures managed nonoperatively can result in chronic pain, aching, and relative weakness of supination, flexion, and grip strength compared with the uninjured side.2,6,7,20
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342 The incidence of distal biceps ruptures has been reported to be 1.2 per 100,000 per year, typically occurring in men between 40 and 60 years.22 Two independent risk factors that have been identified to increase the risk of distal biceps tendon rupture are a history of smoking and steroid use.22 This suggests that smoking and steroid use may weaken the tendon, especially at the tendon-bone interface as the majority of ruptures are avulsion from the bicipital tuberosity. Several methods of fixation have been described in the literature, including bone tunnels, suture anchors, and interference fixation. Although it has not been proven clinically, the Endobutton (Smith & Nephew, Andover, MA, USA) has superior strength in biomechanical tests.9,13,23 The original technique using the Endobutton was described by Bain et al3 but has been slightly modified by the senior author (S.A.S.). The original surgical approach to repair of distal biceps tendon ruptures used a single extensive anterior approach and a bone bridge technique to repair the ruptured tendon to the radius. However, there were significant rates of posterior interosseous nerve (PIN) injuries with this technique, with the nerve lying within millimeters of the distal biceps insertion into the bicipital tuberosity.18 Boyd and Anderson developed a 2-incision technique to reduce the risk of damage to the neurovascular structures, most notably the PIN and lateral cutaneous nerve of the forearm. This approach involves making a second incision over the dorsal aspect of the ulna and approaching the bicipital tuberosity from the dorsum, through the supinator muscle.1,2 However, this resulted in a number of cases of proximal radioulnar synostosis.8 Few studies have directly compared nonoperative vs. operative, anatomic repair of distal biceps ruptures. Baker and Bierwagen showed that patients managed nonoperatively compared with operatively had a reduction in supination strength of 40% and supination endurance of 79%.4 More recently, Chillemi et al showed that those who underwent anatomic repair had better European Society for Surgery of the Shoulder and the Elbow scores, suggesting improved function compared with nonoperative treatment.5 There have been no studies published that have compared Endobutton repair with nonoperative treatment. The aim of this study was to compare the outcome of patients under the care of a single surgeon who have undergone distal biceps tendon repair by a single-incision Endobutton fixation technique with the results of another cohort of patients who elected not to undergo surgery for distal biceps tendon rupture. The outcomes were functional and subjective through questionnaires and measurement of strength and range of motion. All physical outcomes were compared with the contralateral uninjured side. We hypothesized that distal biceps repair by a single anterior incision Endobutton technique is a safe procedure that will result in statistically significantly better subjective and objective functional recovery of supination, flexion, and grip strength compared with the nonoperated group.
A.J. Legg et al.
Materials and methods A retrospective cohort study was performed of 65 consecutive patients diagnosed and managed by a single surgeon between 2002 and 2013, with a minimum follow-up of 6 months. All of the patients were male; no female patients were diagnosed with a distal biceps rupture. All patients had been counseled by the senior author (S.A.S.) after sustaining the distal biceps rupture and were given the same information about the pros and cons of surgical repair vs. nonoperative management. They then were able to make an informed decision to be treated nonoperatively or surgically by a single-incision Endobutton technique. The surgical technique involves making a transverse incision 2 cm distal to the antecubital fossa crease. After dissection through the subcutaneous tissue, on the lateral aspect of the incision, brachioradialis and the lateral cutaneous nerve of the forearm are identified and protected. The bicipital tuberosity is exposed with the arm in full supination and extension to allow easy visualization of the distal biceps tendon footprint and to protect the PIN. The ruptured tendon is then identified and débrided to normal tendon. A 4 × 12-mm titanium Endobutton (Acufex; Smith & Nephew, Andover, MA, USA) is attached using a No. 5 Ethibond (Ethicon, Somerville, NJ, USA) with a Krakow stitch. To allow the Endobutton to flip through 90° on the dorsum of the radius, a 2-mm gap is left between the tendon and the Endobutton (Fig. 1). A guidewire is passed under direct vision and fluoroscopic control in an anterior to posterior direction in the footprint of the distal biceps tendon on the bicipital tuberosity (Fig. 2). A 4.5-mm drill is then used to perforate both volar and dorsal cortices, thus allowing the 4-mm Endobutton to pass though. The distal biceps tendon is then sized, and the appropriate cannulated drill is used to overdrill the volar cortex, which is usually either 6.5 or 7 mm. A Beath pin is passed through the hole in the radial tuberosity in a volar to dorsal direction and through the skin on the dorsal side of the forearm, ensuring that the arm is fully supinated to protect the PIN. The Endobutton and
Figure 1
Endobutton sutured to débrided distal biceps tendon.
Endobutton Repair of Distal Biceps Ruptures
Figure 2 Intraoperative fluoroscopic image of guidewire position on bicipital tuberosity.
Figure 3 Intraoperative fluoroscopic image of Endobutton passing through hole in bicipital tuberosity.
distal biceps tendon are pulled through the hole with the lead sutures. Once the Endobutton is just outside the dorsal cortex of the radius, which can be visualized using fluoroscopy, the trailing sutures are pulled to flip it so it lies flat on the dorsal cortex (Figs. 3 and 4). The elbow is then examined to ensure that full extension and supination are achieved and that the tendon has not been excessively tensioned. After thorough irrigation to remove bone debris, the wound is closed and the elbow is then placed in a backslab at 90° flexion with the forearm in a midprone position for 7 to 10 days to allow the soft tissues to settle and the wound to heal. Progressive early active range of motion exercises are started 7 to 10 days postoperatively, after removal of the backslab. At 6 weeks postoperatively, they are then reviewed in outpatients to ensure that full range of motion has been achieved and to assess for any complications. Anteriorposterior and lateral radiographs are performed to ensure that
343
Figure 4 Intraoperative fluoroscopic image after the Endobutton has been flipped on the dorsal cortex of the radius.
the position of the Endobutton is unchanged from the intraoperative image and that there have not been any radiologic complications. Light lifting is allowed at 3 months, progressing to unrestricted weights at 6 months. The nonoperative cohort received the same early range of motion physiotherapy, which started as soon as pain allowed. At a minimum of 6 months of follow-up, a routine elbow examination was performed on both the injured and uninjured elbows, and all patients completed validated functional elbow scores including Oxford Elbow Score, Mayo Elbow Performance Score, and shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaires. Isometric supination, flexion, and grip strength measurements of the operative side or the side treated nonoperatively were measured and compared with the contralateral, uninjured side using a BTE machine (Baltimore Therapeutic Equipment, Hanover, MD, USA). Isometric supination, flexion, and grip strength was measured with the elbow flexed at 90°, shoulder adducted, and forearm in neutral rotation. As the operative side or the side treated nonoperatively was compared with the contralateral, uninjured side, the subjects who had sustained bilateral injuries could not be included in the analysis, and therefore their results are analyzed as a separate group.
Statistical analysis Unpaired Student t test analysis was used for parametric data (isometric strength) and Mann-Whitney U test for ordinal data (functional questionnaires). P values of < .05 were classified as significant.
344 Table I
A.J. Legg et al. Isometric strength relative to contralateral uninjured side (%)
Operated Nonoperated P value
Flexion
Supination
Grip
92.94 (54.43-130.63) 70.65 (29.62-104.67) .01512
87.91 (42.42-139.00) 59.11 (33.04-88.98) .00414
100.00 (24.41-270.04) 79.16 (39.14-108.46) .16002
Bold values indicate statistical significance.
Table II Relative isometric strength of dominant operated vs. nondominant operated cohorts compared with their contralateral uninjured side (%) Dominant Nondominant P value
Flexion
Supination
Grip
96.88 (61.86-130.63) 85.44 (59.43-103.09) .10727
86.85 (42.42-125.33) 85.70 (44.24-139.00) .90713
105.90 (49.18-125.58) 86.45 (24.41-105.75) .21314
Table III Relative isometric strength of dominant nonoperated vs. nondominant nonoperated compared with their contralateral uninjured side (%) Dominant Nondominant P value
Flexion
Supination
Grip
82.25 (30.25-104.67) 55.18 (29.62-100.99) .38423
59.54 (33.75-88.98) 58.53 (33.03-73.99) .96287
80.91 (39.14-108.46) 76.83 (38.97-96.91) .87019
Results There were 65 men identified to be included in the study, with no women. There were a total of 68 distal biceps tendon ruptures, with 3 patients having sustained bilateral ruptures. Of the 68 ruptures, 55 underwent surgical repair, and 13 patients decided to undergo nonoperative management. Of the 55 distal biceps tendon repairs performed, 40 were available for follow-up, compared with 10 of the 13 ruptures managed nonoperatively; 75% of the distal biceps ruptures were of the dominant side, which is comparable to what has been published in the literature.22 The mean age at the time of injury was 42 years 3 months (30 years 0 months to 60 years 2 months) in the operated cohort compared with 54 years 3 months (42 years 5 months to 57 years 7 months) in the nonoperated cohort.
Follow-up The average follow-up was 3 years 4 months (6 months to 8 years 7 months) in the operated cohort compared with 2 years 1 month (6 months to 6 years 3 months) in the nonoperated cohort.
Strength Using the BTE machine, isometric elbow flexion, forearm supination, and grip strength was examined and compared with the opposite side, and a relative percentage was calculated. This was calculated by dividing the strength measured on the
side that had sustained the distal biceps rupture by the contralateral uninjured side, then multiplying this value by 100 to gain a percentage (Table I). In general, the dominant upper limb is usually approximately 10% stronger than the nondominant limb. As 75% of the injuries affected the dominant side, it is important to identify if this was a possible confounding factor that may bias the results, as a 10% loss of strength in the dominant limb compared with the nondominant limb would suggest that there had been no loss of strength, as they would be equal (100%) (Tables II and III).
Bilateral distal biceps ruptures Three patients sustained bilateral distal biceps ruptures that occurred during 2 separate events. None of them were smokers or had a history of steroid use. One of them decided for both of the distal biceps tendon ruptures to be managed nonoperatively. The second patient had bilateral ruptures repaired. The third patient with bilateral rupture had his first managed nonoperatively, but after sustaining a contralateral injury, he decided to have it repaired as he was unhappy with the nonoperative outcome. The nonoperative dominant side had 77.04% the flexion isometric strength, 37.76% the supination isometric strength, and 105.52% the grip isometric strength compared with the operated nondominant side. The nonoperative side also had a worse QuickDASH and Oxford Shoulder Score compared with the operative side, but the Mayo Elbow Performance Scores were the same (11.4 vs. 0; 38 vs. 47; 100 vs 100).
Endobutton Repair of Distal Biceps Ruptures Table IV
345
Mean functional questionnaire scores
Operated Nonoperated P value
QuickDASH
Oxford
Mayo
6.29 (0-31.8) 14.10 (2.3-40.9) .02123
44.71 (35-48) 38.70 (22-48) .00429
93.13 (70-100) 84.50 (50-100) .01423
Bold values indicate statistical significance.
Table V
Loss of range of motion (degrees)
Operated Nonoperated P value
Flexion
Extension
Supination
Pronation
0 (−20 to 15) 2 (0-20) .12951
0 (−15 to 10) 5 (−5 to 10) .05852
4 (−10 to 20) 1 (0-5) .27601
4 (−5 to 40) 3 (0-20) .88419
Functional questionnaire The operated cohort had significantly better mean functional questionnaire scores in QuickDASH, Oxford Shoulder and Elbow Scores, and Mayo Elbow Performance Score (Table IV).
Range of motion There was no significant loss in range of motion in either cohort compared with the uninjured side, with the greatest loss in range of motion being extension in the nonoperative cohort, although this was not significant (Table V).
Steroids Steroid use has been implicated as an associated risk factor in the rupture of distal biceps. Seven of 47 patients (15%) had previously used steroids, but none of them were taking steroids at the time of injury.
Figure 5 Postoperative follow-up radiograph showing evidence of tunnel lysis.
Smoking
Complications
Three of 47 patients (6%) had a history of smoking. Although this could be implicated as a factor that contributed to the initial rupture, it had no impact on the function or strength after the surgical repair.
Heterotopic ossification and nerve injury, especially to the lateral cutaneous nerve of the forearm, have been reported, with variable incidence. There was 1 stitch abscess that resolved with incision and drainage followed by a short course of oral antibiotics. Two patients developed a postoperative PIN palsy, which fully recovered within 3 months. An incidental finding on follow-up radiographs was heterotopic ossification and tunnel lysis, but it had no impact on function (Figs. 5 and 6; Table VI).
Employment All of the patients in the operative cohort returned to their original employment, with 28 of 33 having a manual job. Two patients in the nonoperative cohort did not return to their preinjury employment. One of them retired because of an unrelated issue, but the other changed his employment from a manual to an administrative job as he was unable to continue his manual job safely.
Discussion There have been few published studies comparing operative repair of distal biceps ruptures with nonoperative treatment,
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A.J. Legg et al.
Figure 6 Postoperative follow-up radiograph showing evidence of heterotopic bone formation. Table VI
Complications
Mild Infection: suture granuloma Lateral antebrachial cutaneous nerve of forearm transient neurapraxia Heterotopic ossification Severe Rerupture Vascular injury Transient PIN palsy Pathologic radial fracture Radioulnar synostosis Stiffness Incidental finding Tunnel lysis
1 8 14 0 0 2 0 0 0 4
PIN, posterior interosseous nerve.
but this is the first study that compares Endobutton repair with nonoperative management. Baker and Bierwagen showed that patients managed nonoperatively compared with operatively had a reduction in supination strength of 40% and supination endurance of 79%. More recently, Chillemi et al showed that those who underwent anatomic repair had better European Society for Surgery of the Shoulder and the Elbow scores, suggesting improved function compared with nonoperative treatment.4,5 The age range of patients in the study was similar to that which has been reported in the literature, between 30 years 1 month and 60 years 2 months at the time of injury, with the majority, 75%, affecting their dominant side.22 However, the cohorts were not self-selected simply by age as the age
ranges overlapped, although the nonoperative cohort’s mean age was 12 years older than that of the operative cohort (54 years 1 month vs. 42 years 3 months). This may be a reflection of the younger patients selecting surgery to try to regain their preinjury strength, compared with the slightly old patients not wanting to go through surgery as they thought they might be able to function with the potential strength deficit. This study supports the published evidence in the literature that anatomic repair of distal biceps tendon ruptures restores flexion and supination strength to nearly a preinjury level, with supination and flexion isometric strength being restored to 90.97% and 93.66% of the uninjured side, respectively.12,19 Grip strength was nearly equal to the uninjured side (98.98%). There was no significant difference in isometric flexion, supination, or grip strength in the operated group whether the dominant or nondominant side was affected. We identified 3 patients (6.4%) who had sustained bilateral distal biceps ruptures. The high incidence of bilateral ruptures supports the evidence that some patients may have a predisposition to distal biceps rupture.21 There may be a genetic component as to why certain patients may develop the tendinopathy that usually precedes the tendon rupture. This potentially could be an anatomic variant or a structural variant within the tendon itself, with most of the tendons showing degenerative changes. Green et al reported the largest series of distal biceps repairs during 22 years, identifying a cumulative incidence of 8%, and although our results suggest a higher incidence, our cohort size was much smaller and for a shorter time, which could easily bias such a result.10 The functional questionnaire scores of the operative cohort were significantly better than in the nonoperative cohort. The QuickDASH score in the operative cohort was 6.29 compared with 14.10 in the nonoperative cohort. The operative score was similar to that reported by McKee et al, who reported that mean DASH scores after repair through an anterior approach were similar to those of controls, 8.2 vs. 6.2.17 Our Mayo Elbow Performance Scores were similar to those reported in the literature, with a score of 93.13 of 100. Leon et al reported a similar score of 95 at a minimum follow-up of 6 months.15 Although heterotopic ossification was identified on a number of follow-up radiographs, it was not possible to quantify this on the basis of the plain radiographs. However, in the patients with heterotopic ossification, there was no evidence that it resulted in any symptomatic or functional deficit, with no loss of range of motion or discomfort. All of the radiographs that identified heterotopic ossification had increased heterotopic ossification in the follow-up radiographs compared with their routine 6-week follow-up radiograph, but there was no correlation between duration of time after surgery and amount of heterotopic ossification that could be estimated from plain radiographs. It was not possible to conclude from these images that the heterotopic ossification will not progress further, as future follow-up radiographs would be required. Heterotopic ossification may be linked to bone debris created
Endobutton Repair of Distal Biceps Ruptures during making the hole in the radial tuberosity. The amount of debris created is minimized with this technique as the cannulated drills are used rather than a burr, and thorough irrigation of the surgical bed is performed before wound closure. A single anterior incision approach to repair distal biceps tendon ruptures was first described more than 100 years ago by Johnson, and since then, alternative approaches including a 2-incision approach have been popularized.16 The main driving force for the development of the 2-incision technique was to reduce the risk of nerve injury, in particular of the PIN. There were 2 transient PIN palsies that recovered fully within 3 months; therefore, it was most likely a neurapraxia as a result of retractor misplacement or not keeping the forearm fully supinated when the drill or Beath pin was inserted. In comparison, there have been no PIN injuries reported in the literature with the 2-incision technique, but proximal radioulnar synostosis has been reported and has been postulated to be secondary to subperiosteal dissection.1 Tunnel lysis as a result of using the Endobutton may be due to pistoning of the tendon within the bone, as the elbow flexes and extends, compared with interference fixation. Tunnel lysis is a well-described phenomenon with anterior cruciate ligament reconstruction using a suspensory Endobutton technique. However, there is no evidence that it has any detrimental effect on functional outcome. Although this can be potentially troublesome when anterior cruciate ligament revision surgery is required as the defect may require bone grafting or another technique to fill the defect, there is no risk of fracture. In comparison, the initial hole created in the bicipital tuberosity is relatively large compared with the width of the bone, and therefore any significant increase in size potentially could result in a fracture. It was not possible to identify if the lysis was progressive or not from 1 follow-up radiograph. However, there was no correlation between the size of the lysis and the length of follow-up period, and there were no pathologic fractures. Although 50 distal biceps ruptures in 47 patients were included in the study, a total of 68 distal biceps ruptures in 65 patients were identified that could have been included. This equates to 26% being lost to final follow-up. However, at the time of discharge at 6 months postoperatively, of those who were not reviewed in the follow-up clinic, there were no complications or patient-reported problems documented in the hospital medical notes. A recent retrospective study by Hinchey et al showed that any complications that occurred in their cohort were identified in the first 3 weeks postoperatively.11 Therefore, although we were unable to measure the functional outcomes, we can fairly confidently assume that there were not any complications in the cohort patients who were unable to attend the study follow-up. However, we cannot exclude the small possibility that they may have sustained a rerupture or a redial fracture and not returned to the senior author (S.A.S.) for review. Both of these complications could occur after the minimum 6-month follow-up that was re-
347 quired to be included in the study, although they are both rare complications. There was one-third the number of patients in the nonoperative cohort as in the surgical cohort, which potentially leaves the study subject to bias. This type of study also allows the potential for surgeon bias, unlike a randomized control trial. It would not be ethical to perform a prospective randomized control trial and to randomize patients to a nonoperative and operative cohort as surgical repair has been shown to have significantly improved functional outcome.4,5
Conclusion Our study shows that a single-incision Endobutton repair of acute distal biceps ruptures is a safe technique that allows early mobilization and restoration of full range of motion and nearly normal flexion and supination strength. This in comparison to distal biceps ruptures managed nonoperatively, which result in significantly weaker isometric flexion and supination strength in addition to functional outcome questionnaire scores.
Disclaimer The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. Funding was received from Chesterfield Royal Hospital Research Fund to reimburse participants for their travel expenses (R & D number 2012/52).
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348 8. Failla M, Amadio PC, Morrey BF, Beckenbaugh RD. Proximal radioulnar synostosis after repair of distal biceps brachii rupture by the two-incision technique. Report of four cases. Clin Orthop Relat Res 1990;253:133-6. 9. Fox JA, Fernandez JJ. Single incision technique for distal biceps tendon repair: using the Endobutton. Oper Tech Sports Med 2003;11:42-6. http://dx.doi.org/10.1053/otsm.2003.35891 10. Green JB, Skaife TL, Leslie BM. Bilateral distal biceps tendon ruptures. J Hand Surg Am 2012;37:120-3. http://dx.doi.org/10.1016/ j.jhsa.2011.09.043 11. Hinchey JW, Aronowitz JG, Sanchez-Sotelo J, Morrey BF. Re-rupture rate of primarily repaired distal biceps tendon injuries. J Shoulder Elbow Surg 2014;23:850-4. http://dx.doi.org/10.1016/j.jse.2014.02.006 12. Kelly EW, Steinmann S, O’Driscoll SW. Surgical treatment of partial distal biceps tendon ruptures through a single posterior incision. J Shoulder Elbow Surg 2003;12:456-61. http://dx.doi.org/10.1016/ S1058-2746(03)00052-1 13. Kettler M, Tingart MJ, Lunger J, Kuhn V. Reattachment of the distal tendon of biceps: factors affecting the failure strengths of the repair. J Bone Joint Surg Br 2008;90:103-6. http://dx.doi.org/10.1302/0301620X.90B1.19285 14. Khan W, Agarwal M, Funk L. Repair of distal biceps tendon ruptures with Biotenodesis screw. Arch Orthop Trauma Surg 2004;124:206-8. http://dx.doi.org/10.1007/s00402-004-0639-8 15. Leon RAF, Ibanez EI, Mont RN, Jaen TF. Functional recovery and re-introduction to sport, after repair of distal biceps tear by two-incision technique Mayo. Br J Sports Med 2013;47:e2. http://dx.doi.org/10.1136/ bjsports-2013-092459.37
A.J. Legg et al. 16. Mazzocca AD, Alberta FG, ElAttrache NS, Romeo AA. Single incision technique using an interference screw for the repair of distal biceps tendon ruptures. Oper Tech Sports Med 2003;11:36-41. http://dx.doi.org/ 10.1053/otsm.2003.35886 17. McKee M, Hirji R, Schemitsch EH, Wild LM, Waddell JP. Patientoriented functional outcome after repair of distal biceps tendon ruptures using a single-incision technique. J Shoulder Elbow Surg 2005;14:302-6. http://dx.doi.org/10.1016/j.jse.2004.09.007 18. Meherin JM, Kilgore ES. The treatment of ruptures of the distal biceps brachii tendon. Am J Surg 1960;99:636-40. 19. Morrey BP, Askew LJ, An KN, Dobyns JH. Rupture of the distal tendon of the biceps brachii. A biomechanical study. J Bone Joint Surg Am 1985;67:418-21. 20. Nesterenko S, Domire ZJ, Morrey BF, Sanchez-Sotelo J. Elbow strength and endurance in patients with a ruptured distal biceps tendon. J Shoulder Elbow Surg 2010;19:184-9. http://dx.doi.org/10.1016/j.jse.2009 .06.001 21. Rokito A Ioin I. Simultaneous bilateral distal biceps tendon rupture during a preacher curl exercise: a case report. Bull NYU Hosp Jt Dis 2008;66:68-71. 22. Safran MR, Graham SM. Distal biceps tendon ruptures: incidence, demographics, and the effect of smoking. Clin Orthop Relat Res 2002;404:275-83. http://dx.doi.org/10.1097/00003086-200211000 -00042 23. Spang JT, Weinhold PS, Karas SG. A biomechanical comparison of Endobutton versus suture anchor repair of distal biceps tendon injuries. J Shoulder Elbow Surg 2006;15:509-14. http://dx.doi.org/10.1016/ j.jse.2005.09.020
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ELBOW
A comparison of nonoperative vs. Endobutton repair of distal biceps ruptures Andrew J. Legg, FRCS (Orth)*, Richard Stevens, MRCS, Nanette O. Oakes, BSc, Shantanu A. Shahane, FRCS (Orth) Chesterfield Royal Hospital, Chesterfield, Derbyshire, UK Background: The aim of this study was to compare the outcome of patients who have undergone distal biceps tendon repair by a single-incision Endobutton fixation technique with the results of another cohort of patients who elected not to undergo surgery for distal biceps tendon rupture. Methods: A retrospective cohort study was performed of patients diagnosed with distal biceps ruptures, repaired with an Endobutton (Smith & Nephew, Andover, MA, USA) technique or treated nonoperatively by the senior surgeon (S.A.S.). With a minimum follow-up of 6 months, a routine elbow examination, radiographs, and functional questionnaires were performed. Isometric supination, flexion, and grip strength was measured using a BTE machine (Baltimore Therapeutic Equipment, Hanover, MD, USA). There were 47 patients available for follow-up with 50 distal biceps ruptures; 40 ruptures have undergone repair, and 10 have been managed nonoperatively. Three patients had sustained bilateral ruptures. Results: There was a significant difference in flexion and supination isometric strength between the operative and nonoperative cohorts compared with the uninjured contralateral side (92.94% vs. 70.65%, P = .01512; 87.91% vs 59.11%, P = .00414, respectively). The difference in grip strengths between the 2 cohorts compared with the uninjured side was not significant (100.00% vs. 79.16%; P = .16002). The operated cohort had significantly better QuickDASH score, Oxford Elbow Score, and Mayo Elbow Performance Score (6.29 vs. 14.10, P = .02123; 44.71 vs. 38.70, P = .00429; 93.13 vs. 84.50, P = .01423). Conclusion: Repair of distal biceps ruptures using an Endobutton fixation results in nearly normal return of strength and function, which is significantly better than in those managed nonoperatively. Level of evidence: Level III, Retrospective Cohort Design; Treatment Study © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees Keywords: Biceps; Endobutton; distal; repair; tendon; rupture
Starks reported the first distal biceps tendon rupture in 1843. More than 50 years later in 1897, Johnson reported repair of Ethics approval was gained from the NRES Committee East Midlands— Nottingham 1 (REC reference 13/EM/0053). *Reprint requests: Andrew J. Legg, FRCS (Orth), 6 Edmonton Place, Chapel Allerton, Leeds, West Yorkshire LS7 4LP, UK. E-mail address: [email protected] (A.J. Legg).
the distal biceps tendon using a single anterior incision approach.14,16 The majority of biceps tendon ruptures involve the long head proximally or, more infrequently, the short head; only 3% of all biceps tendon ruptures occur in the distal biceps tendon.2 Distal biceps ruptures managed nonoperatively can result in chronic pain, aching, and relative weakness of supination, flexion, and grip strength compared with the uninjured side.2,6,7,20
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342 The incidence of distal biceps ruptures has been reported to be 1.2 per 100,000 per year, typically occurring in men between 40 and 60 years.22 Two independent risk factors that have been identified to increase the risk of distal biceps tendon rupture are a history of smoking and steroid use.22 This suggests that smoking and steroid use may weaken the tendon, especially at the tendon-bone interface as the majority of ruptures are avulsion from the bicipital tuberosity. Several methods of fixation have been described in the literature, including bone tunnels, suture anchors, and interference fixation. Although it has not been proven clinically, the Endobutton (Smith & Nephew, Andover, MA, USA) has superior strength in biomechanical tests.9,13,23 The original technique using the Endobutton was described by Bain et al3 but has been slightly modified by the senior author (S.A.S.). The original surgical approach to repair of distal biceps tendon ruptures used a single extensive anterior approach and a bone bridge technique to repair the ruptured tendon to the radius. However, there were significant rates of posterior interosseous nerve (PIN) injuries with this technique, with the nerve lying within millimeters of the distal biceps insertion into the bicipital tuberosity.18 Boyd and Anderson developed a 2-incision technique to reduce the risk of damage to the neurovascular structures, most notably the PIN and lateral cutaneous nerve of the forearm. This approach involves making a second incision over the dorsal aspect of the ulna and approaching the bicipital tuberosity from the dorsum, through the supinator muscle.1,2 However, this resulted in a number of cases of proximal radioulnar synostosis.8 Few studies have directly compared nonoperative vs. operative, anatomic repair of distal biceps ruptures. Baker and Bierwagen showed that patients managed nonoperatively compared with operatively had a reduction in supination strength of 40% and supination endurance of 79%.4 More recently, Chillemi et al showed that those who underwent anatomic repair had better European Society for Surgery of the Shoulder and the Elbow scores, suggesting improved function compared with nonoperative treatment.5 There have been no studies published that have compared Endobutton repair with nonoperative treatment. The aim of this study was to compare the outcome of patients under the care of a single surgeon who have undergone distal biceps tendon repair by a single-incision Endobutton fixation technique with the results of another cohort of patients who elected not to undergo surgery for distal biceps tendon rupture. The outcomes were functional and subjective through questionnaires and measurement of strength and range of motion. All physical outcomes were compared with the contralateral uninjured side. We hypothesized that distal biceps repair by a single anterior incision Endobutton technique is a safe procedure that will result in statistically significantly better subjective and objective functional recovery of supination, flexion, and grip strength compared with the nonoperated group.
A.J. Legg et al.
Materials and methods A retrospective cohort study was performed of 65 consecutive patients diagnosed and managed by a single surgeon between 2002 and 2013, with a minimum follow-up of 6 months. All of the patients were male; no female patients were diagnosed with a distal biceps rupture. All patients had been counseled by the senior author (S.A.S.) after sustaining the distal biceps rupture and were given the same information about the pros and cons of surgical repair vs. nonoperative management. They then were able to make an informed decision to be treated nonoperatively or surgically by a single-incision Endobutton technique. The surgical technique involves making a transverse incision 2 cm distal to the antecubital fossa crease. After dissection through the subcutaneous tissue, on the lateral aspect of the incision, brachioradialis and the lateral cutaneous nerve of the forearm are identified and protected. The bicipital tuberosity is exposed with the arm in full supination and extension to allow easy visualization of the distal biceps tendon footprint and to protect the PIN. The ruptured tendon is then identified and débrided to normal tendon. A 4 × 12-mm titanium Endobutton (Acufex; Smith & Nephew, Andover, MA, USA) is attached using a No. 5 Ethibond (Ethicon, Somerville, NJ, USA) with a Krakow stitch. To allow the Endobutton to flip through 90° on the dorsum of the radius, a 2-mm gap is left between the tendon and the Endobutton (Fig. 1). A guidewire is passed under direct vision and fluoroscopic control in an anterior to posterior direction in the footprint of the distal biceps tendon on the bicipital tuberosity (Fig. 2). A 4.5-mm drill is then used to perforate both volar and dorsal cortices, thus allowing the 4-mm Endobutton to pass though. The distal biceps tendon is then sized, and the appropriate cannulated drill is used to overdrill the volar cortex, which is usually either 6.5 or 7 mm. A Beath pin is passed through the hole in the radial tuberosity in a volar to dorsal direction and through the skin on the dorsal side of the forearm, ensuring that the arm is fully supinated to protect the PIN. The Endobutton and
Figure 1
Endobutton sutured to débrided distal biceps tendon.
Endobutton Repair of Distal Biceps Ruptures
Figure 2 Intraoperative fluoroscopic image of guidewire position on bicipital tuberosity.
Figure 3 Intraoperative fluoroscopic image of Endobutton passing through hole in bicipital tuberosity.
distal biceps tendon are pulled through the hole with the lead sutures. Once the Endobutton is just outside the dorsal cortex of the radius, which can be visualized using fluoroscopy, the trailing sutures are pulled to flip it so it lies flat on the dorsal cortex (Figs. 3 and 4). The elbow is then examined to ensure that full extension and supination are achieved and that the tendon has not been excessively tensioned. After thorough irrigation to remove bone debris, the wound is closed and the elbow is then placed in a backslab at 90° flexion with the forearm in a midprone position for 7 to 10 days to allow the soft tissues to settle and the wound to heal. Progressive early active range of motion exercises are started 7 to 10 days postoperatively, after removal of the backslab. At 6 weeks postoperatively, they are then reviewed in outpatients to ensure that full range of motion has been achieved and to assess for any complications. Anteriorposterior and lateral radiographs are performed to ensure that
343
Figure 4 Intraoperative fluoroscopic image after the Endobutton has been flipped on the dorsal cortex of the radius.
the position of the Endobutton is unchanged from the intraoperative image and that there have not been any radiologic complications. Light lifting is allowed at 3 months, progressing to unrestricted weights at 6 months. The nonoperative cohort received the same early range of motion physiotherapy, which started as soon as pain allowed. At a minimum of 6 months of follow-up, a routine elbow examination was performed on both the injured and uninjured elbows, and all patients completed validated functional elbow scores including Oxford Elbow Score, Mayo Elbow Performance Score, and shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaires. Isometric supination, flexion, and grip strength measurements of the operative side or the side treated nonoperatively were measured and compared with the contralateral, uninjured side using a BTE machine (Baltimore Therapeutic Equipment, Hanover, MD, USA). Isometric supination, flexion, and grip strength was measured with the elbow flexed at 90°, shoulder adducted, and forearm in neutral rotation. As the operative side or the side treated nonoperatively was compared with the contralateral, uninjured side, the subjects who had sustained bilateral injuries could not be included in the analysis, and therefore their results are analyzed as a separate group.
Statistical analysis Unpaired Student t test analysis was used for parametric data (isometric strength) and Mann-Whitney U test for ordinal data (functional questionnaires). P values of < .05 were classified as significant.
344 Table I
A.J. Legg et al. Isometric strength relative to contralateral uninjured side (%)
Operated Nonoperated P value
Flexion
Supination
Grip
92.94 (54.43-130.63) 70.65 (29.62-104.67) .01512
87.91 (42.42-139.00) 59.11 (33.04-88.98) .00414
100.00 (24.41-270.04) 79.16 (39.14-108.46) .16002
Bold values indicate statistical significance.
Table II Relative isometric strength of dominant operated vs. nondominant operated cohorts compared with their contralateral uninjured side (%) Dominant Nondominant P value
Flexion
Supination
Grip
96.88 (61.86-130.63) 85.44 (59.43-103.09) .10727
86.85 (42.42-125.33) 85.70 (44.24-139.00) .90713
105.90 (49.18-125.58) 86.45 (24.41-105.75) .21314
Table III Relative isometric strength of dominant nonoperated vs. nondominant nonoperated compared with their contralateral uninjured side (%) Dominant Nondominant P value
Flexion
Supination
Grip
82.25 (30.25-104.67) 55.18 (29.62-100.99) .38423
59.54 (33.75-88.98) 58.53 (33.03-73.99) .96287
80.91 (39.14-108.46) 76.83 (38.97-96.91) .87019
Results There were 65 men identified to be included in the study, with no women. There were a total of 68 distal biceps tendon ruptures, with 3 patients having sustained bilateral ruptures. Of the 68 ruptures, 55 underwent surgical repair, and 13 patients decided to undergo nonoperative management. Of the 55 distal biceps tendon repairs performed, 40 were available for follow-up, compared with 10 of the 13 ruptures managed nonoperatively; 75% of the distal biceps ruptures were of the dominant side, which is comparable to what has been published in the literature.22 The mean age at the time of injury was 42 years 3 months (30 years 0 months to 60 years 2 months) in the operated cohort compared with 54 years 3 months (42 years 5 months to 57 years 7 months) in the nonoperated cohort.
Follow-up The average follow-up was 3 years 4 months (6 months to 8 years 7 months) in the operated cohort compared with 2 years 1 month (6 months to 6 years 3 months) in the nonoperated cohort.
Strength Using the BTE machine, isometric elbow flexion, forearm supination, and grip strength was examined and compared with the opposite side, and a relative percentage was calculated. This was calculated by dividing the strength measured on the
side that had sustained the distal biceps rupture by the contralateral uninjured side, then multiplying this value by 100 to gain a percentage (Table I). In general, the dominant upper limb is usually approximately 10% stronger than the nondominant limb. As 75% of the injuries affected the dominant side, it is important to identify if this was a possible confounding factor that may bias the results, as a 10% loss of strength in the dominant limb compared with the nondominant limb would suggest that there had been no loss of strength, as they would be equal (100%) (Tables II and III).
Bilateral distal biceps ruptures Three patients sustained bilateral distal biceps ruptures that occurred during 2 separate events. None of them were smokers or had a history of steroid use. One of them decided for both of the distal biceps tendon ruptures to be managed nonoperatively. The second patient had bilateral ruptures repaired. The third patient with bilateral rupture had his first managed nonoperatively, but after sustaining a contralateral injury, he decided to have it repaired as he was unhappy with the nonoperative outcome. The nonoperative dominant side had 77.04% the flexion isometric strength, 37.76% the supination isometric strength, and 105.52% the grip isometric strength compared with the operated nondominant side. The nonoperative side also had a worse QuickDASH and Oxford Shoulder Score compared with the operative side, but the Mayo Elbow Performance Scores were the same (11.4 vs. 0; 38 vs. 47; 100 vs 100).
Endobutton Repair of Distal Biceps Ruptures Table IV
345
Mean functional questionnaire scores
Operated Nonoperated P value
QuickDASH
Oxford
Mayo
6.29 (0-31.8) 14.10 (2.3-40.9) .02123
44.71 (35-48) 38.70 (22-48) .00429
93.13 (70-100) 84.50 (50-100) .01423
Bold values indicate statistical significance.
Table V
Loss of range of motion (degrees)
Operated Nonoperated P value
Flexion
Extension
Supination
Pronation
0 (−20 to 15) 2 (0-20) .12951
0 (−15 to 10) 5 (−5 to 10) .05852
4 (−10 to 20) 1 (0-5) .27601
4 (−5 to 40) 3 (0-20) .88419
Functional questionnaire The operated cohort had significantly better mean functional questionnaire scores in QuickDASH, Oxford Shoulder and Elbow Scores, and Mayo Elbow Performance Score (Table IV).
Range of motion There was no significant loss in range of motion in either cohort compared with the uninjured side, with the greatest loss in range of motion being extension in the nonoperative cohort, although this was not significant (Table V).
Steroids Steroid use has been implicated as an associated risk factor in the rupture of distal biceps. Seven of 47 patients (15%) had previously used steroids, but none of them were taking steroids at the time of injury.
Figure 5 Postoperative follow-up radiograph showing evidence of tunnel lysis.
Smoking
Complications
Three of 47 patients (6%) had a history of smoking. Although this could be implicated as a factor that contributed to the initial rupture, it had no impact on the function or strength after the surgical repair.
Heterotopic ossification and nerve injury, especially to the lateral cutaneous nerve of the forearm, have been reported, with variable incidence. There was 1 stitch abscess that resolved with incision and drainage followed by a short course of oral antibiotics. Two patients developed a postoperative PIN palsy, which fully recovered within 3 months. An incidental finding on follow-up radiographs was heterotopic ossification and tunnel lysis, but it had no impact on function (Figs. 5 and 6; Table VI).
Employment All of the patients in the operative cohort returned to their original employment, with 28 of 33 having a manual job. Two patients in the nonoperative cohort did not return to their preinjury employment. One of them retired because of an unrelated issue, but the other changed his employment from a manual to an administrative job as he was unable to continue his manual job safely.
Discussion There have been few published studies comparing operative repair of distal biceps ruptures with nonoperative treatment,
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A.J. Legg et al.
Figure 6 Postoperative follow-up radiograph showing evidence of heterotopic bone formation. Table VI
Complications
Mild Infection: suture granuloma Lateral antebrachial cutaneous nerve of forearm transient neurapraxia Heterotopic ossification Severe Rerupture Vascular injury Transient PIN palsy Pathologic radial fracture Radioulnar synostosis Stiffness Incidental finding Tunnel lysis
1 8 14 0 0 2 0 0 0 4
PIN, posterior interosseous nerve.
but this is the first study that compares Endobutton repair with nonoperative management. Baker and Bierwagen showed that patients managed nonoperatively compared with operatively had a reduction in supination strength of 40% and supination endurance of 79%. More recently, Chillemi et al showed that those who underwent anatomic repair had better European Society for Surgery of the Shoulder and the Elbow scores, suggesting improved function compared with nonoperative treatment.4,5 The age range of patients in the study was similar to that which has been reported in the literature, between 30 years 1 month and 60 years 2 months at the time of injury, with the majority, 75%, affecting their dominant side.22 However, the cohorts were not self-selected simply by age as the age
ranges overlapped, although the nonoperative cohort’s mean age was 12 years older than that of the operative cohort (54 years 1 month vs. 42 years 3 months). This may be a reflection of the younger patients selecting surgery to try to regain their preinjury strength, compared with the slightly old patients not wanting to go through surgery as they thought they might be able to function with the potential strength deficit. This study supports the published evidence in the literature that anatomic repair of distal biceps tendon ruptures restores flexion and supination strength to nearly a preinjury level, with supination and flexion isometric strength being restored to 90.97% and 93.66% of the uninjured side, respectively.12,19 Grip strength was nearly equal to the uninjured side (98.98%). There was no significant difference in isometric flexion, supination, or grip strength in the operated group whether the dominant or nondominant side was affected. We identified 3 patients (6.4%) who had sustained bilateral distal biceps ruptures. The high incidence of bilateral ruptures supports the evidence that some patients may have a predisposition to distal biceps rupture.21 There may be a genetic component as to why certain patients may develop the tendinopathy that usually precedes the tendon rupture. This potentially could be an anatomic variant or a structural variant within the tendon itself, with most of the tendons showing degenerative changes. Green et al reported the largest series of distal biceps repairs during 22 years, identifying a cumulative incidence of 8%, and although our results suggest a higher incidence, our cohort size was much smaller and for a shorter time, which could easily bias such a result.10 The functional questionnaire scores of the operative cohort were significantly better than in the nonoperative cohort. The QuickDASH score in the operative cohort was 6.29 compared with 14.10 in the nonoperative cohort. The operative score was similar to that reported by McKee et al, who reported that mean DASH scores after repair through an anterior approach were similar to those of controls, 8.2 vs. 6.2.17 Our Mayo Elbow Performance Scores were similar to those reported in the literature, with a score of 93.13 of 100. Leon et al reported a similar score of 95 at a minimum follow-up of 6 months.15 Although heterotopic ossification was identified on a number of follow-up radiographs, it was not possible to quantify this on the basis of the plain radiographs. However, in the patients with heterotopic ossification, there was no evidence that it resulted in any symptomatic or functional deficit, with no loss of range of motion or discomfort. All of the radiographs that identified heterotopic ossification had increased heterotopic ossification in the follow-up radiographs compared with their routine 6-week follow-up radiograph, but there was no correlation between duration of time after surgery and amount of heterotopic ossification that could be estimated from plain radiographs. It was not possible to conclude from these images that the heterotopic ossification will not progress further, as future follow-up radiographs would be required. Heterotopic ossification may be linked to bone debris created
Endobutton Repair of Distal Biceps Ruptures during making the hole in the radial tuberosity. The amount of debris created is minimized with this technique as the cannulated drills are used rather than a burr, and thorough irrigation of the surgical bed is performed before wound closure. A single anterior incision approach to repair distal biceps tendon ruptures was first described more than 100 years ago by Johnson, and since then, alternative approaches including a 2-incision approach have been popularized.16 The main driving force for the development of the 2-incision technique was to reduce the risk of nerve injury, in particular of the PIN. There were 2 transient PIN palsies that recovered fully within 3 months; therefore, it was most likely a neurapraxia as a result of retractor misplacement or not keeping the forearm fully supinated when the drill or Beath pin was inserted. In comparison, there have been no PIN injuries reported in the literature with the 2-incision technique, but proximal radioulnar synostosis has been reported and has been postulated to be secondary to subperiosteal dissection.1 Tunnel lysis as a result of using the Endobutton may be due to pistoning of the tendon within the bone, as the elbow flexes and extends, compared with interference fixation. Tunnel lysis is a well-described phenomenon with anterior cruciate ligament reconstruction using a suspensory Endobutton technique. However, there is no evidence that it has any detrimental effect on functional outcome. Although this can be potentially troublesome when anterior cruciate ligament revision surgery is required as the defect may require bone grafting or another technique to fill the defect, there is no risk of fracture. In comparison, the initial hole created in the bicipital tuberosity is relatively large compared with the width of the bone, and therefore any significant increase in size potentially could result in a fracture. It was not possible to identify if the lysis was progressive or not from 1 follow-up radiograph. However, there was no correlation between the size of the lysis and the length of follow-up period, and there were no pathologic fractures. Although 50 distal biceps ruptures in 47 patients were included in the study, a total of 68 distal biceps ruptures in 65 patients were identified that could have been included. This equates to 26% being lost to final follow-up. However, at the time of discharge at 6 months postoperatively, of those who were not reviewed in the follow-up clinic, there were no complications or patient-reported problems documented in the hospital medical notes. A recent retrospective study by Hinchey et al showed that any complications that occurred in their cohort were identified in the first 3 weeks postoperatively.11 Therefore, although we were unable to measure the functional outcomes, we can fairly confidently assume that there were not any complications in the cohort patients who were unable to attend the study follow-up. However, we cannot exclude the small possibility that they may have sustained a rerupture or a redial fracture and not returned to the senior author (S.A.S.) for review. Both of these complications could occur after the minimum 6-month follow-up that was re-
347 quired to be included in the study, although they are both rare complications. There was one-third the number of patients in the nonoperative cohort as in the surgical cohort, which potentially leaves the study subject to bias. This type of study also allows the potential for surgeon bias, unlike a randomized control trial. It would not be ethical to perform a prospective randomized control trial and to randomize patients to a nonoperative and operative cohort as surgical repair has been shown to have significantly improved functional outcome.4,5
Conclusion Our study shows that a single-incision Endobutton repair of acute distal biceps ruptures is a safe technique that allows early mobilization and restoration of full range of motion and nearly normal flexion and supination strength. This in comparison to distal biceps ruptures managed nonoperatively, which result in significantly weaker isometric flexion and supination strength in addition to functional outcome questionnaire scores.
Disclaimer The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. Funding was received from Chesterfield Royal Hospital Research Fund to reimburse participants for their travel expenses (R & D number 2012/52).
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