Ann R Coll Surg Engl 2002; 84: 43-46
The Royal College of Surgeons of England
Original article
A comparison between forefoot plaster and wooden soled shoes following Mitchell's osteotomy for hallux valgus Mark C Forster, Sunil Dhar Department of Orthopaedics, Nottingham City Hospital, Nottingham, UK Between 1 October 1997 and 1 November 1998, 43 patients (59 feet) were treated with a standard Mitchell's osteotomy for hallux valgus. Of these, 26 patients (36 feet) were treated postoperatively in a forefoot plaster. The other 17 patients (23 feet) were treated with a wooden soled shoe. There was no significant difference between the 2 groups for age, indication for surgery, pre-operative deformity or grade of the operating surgeon. There was no significant difference in the mean time immobilised, mean time to union or complications. The patients were interviewed by telephone after a mean follow-up of 9.4 months. There was no significant difference in results between the 2 groups. This suggests that a forefoot plaster following Mitchell's osteotomy is unnecessary. Postoperative mobilisation in a wooden soled shoe can be used as an alternative.
Key words: Hallux valgus Mitchell's osteotomy Postoperative care Wooden soled shoe Forefoot plaster -
The correction of hallux valgus by a distal first metatarsal osteotomy was first described in 1881 by Reverdin.1 Mitchell popularised the double stepcut osteotomy of the distal first metatarsal.2'3 This operation has been performed for many years and has good results, 82-97% of feet being satisfactorily corrected.24 Traditionally, below-knee or forefoot plasters have been used postoperatively to hold the osteotomy in place. More recently, wooden soled shoes have been used as an alternative. They offer some advantages in that they can be removed at night and when not weight bearing, which is of obvious convenience to the patient. They also allow access for wound assessment but it is uncertain whether they provide as good fixation. Our experience suggests that there is little difference between the two methods, but there have been no trials comparing the use of forefoot plasters and wooden soled shoes.
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The aim of this study was to see if there was any difference in outcome between those patients treated with forefoot plaster and those with wooden soled shoes.
Patients and Methods
The case notes and radiographs of all patients who underwent Mitchell's osteotomy between 1 October 1997 and 1 November 1998 were reviewed. The patients were divided into 2 groups. The first group were those who had been treated with a forefoot plaster (Fig. 1) and the second group were those treated with a wooden soled shoe (Fig. 2) postoperatively. All the patients underwent a standard Mitchell's osteotomy with the fragments held by a suture placed through drill holes in the first metatarsal. Postoperatively, those in the forefoot plaster group were placed initially in
Correspondence to: Mark Forster, 9 Lamboume Avenue, Ashboume DE6 1BP, UK E-mail:
[email protected] Ann R Coll Surg Engl 2002; 84
43
FORSTER
FOREFOOT PLASTER OR WOODEN SOLED SHOES - MITCHELUS OSTEOTOMY FOR HALLUX VALGUS
Figure 1 A forefoot plaster
intermetatarsal angles (IMA) were measured from the radiographs. The patients were also contacted by telephone and assessed using a forefoot score.7 The forefoot score assesses pain (0-30 points), functional restriction (0-15 points), footwear restriction (0-10 points), callus (0-10 points), alignment (0-5 points) and stiffness (0-5 points). This gives a range of scores from 0 (bad) to a maximum of 75 points (good). The patients were asked if each symptom was improved, worsened, or not changed by the operation. Patient satisfaction was also assessed. The data gathered for each group were analysed using the chi squared test for parametric data and the MannWhitney U test for non-parametric data. Results A total of 43 patients (59 feet) had Mitchell's osteotomies at the Nottingham City Hospital between 1 October 1997 and 1 November 1998. The data collected are summarised in Table 1 Summary of data collectedfrom casenotes and X-rays
Forefoot plaster
Wooden soled
shoe
Figure 2 A wooden soled shoe
a plaster slab covering the medial border of the foot, held in place by a wool and crepe bandage. They were treated with bedrest and elevation for 24-48 h. Ankle exercises were encouraged to prevent ankle stiffness. On the first postoperative day, a check radiograph was taken to assess the position of the osteotomy. At 24-48 h, they were changed to a forefoot Scotchcast with a separator between the hallux and second toe. With the help of the physiotherapists, the patients were then mobilised with crutches and their foot flat to the floor. They were discharged home when they could mobilise safely. The wooden soled shoe group were treated similarly except that no plaster slab or forefoot Scotchcast were used. The patients were treated in a wool and crepe bandage and mobilised foot flat to the floor in a wooden soled shoe. Both groups were seen at 2 weeks for a wound check and removal of sutures and then at 6 weeks for removal of the cast or shoe, X-ray and clinical assessment. The patients were then seen as clinically indicated. The following details were recorded for each patient: age, sex, indication for surgery, grade of surgeon, time immobilised, compliance, time to union and complications. The pre- and postoperative hallux valgus angles (HVA) and 44
Patients Feet Mean age (years) Age range (years) Sex
26 36 47.9 16-73 All women
17 23 47.1 17-72 2 men, 15 women
Indications for surgery (number of feet) 27 (75%) Pain 7 (19.4%) Deformity 18 (50%) Footwear restriction
20 (87%) 2 (8.7%) 12 (52.2%)
Surgeon Consultant Registrar
14 (38.9%) 22 (61.1%)
7 (30.4%) 16 (69.6%)
31.30 13.80 16.90 7.60 14.40 6.20
35.60 15.00 17.10 8.30 18.50 6.60
6.5 7.9
6.6 7.4
0 (0%) 0 (0%)
Metatarsalgia Infection - superficial
4 (11.1%) 1 (2.8%) 4 (11.1%) 5 (13.9%) 1 (2.8%)
Recurrence
0 (0%)
Angles Mean pre-op HVA Mean pre-op IMA Mean postop HVA Mean postop IMA Mean correction HVA Mean correction IMA Times (weeks) Mean time immobilised Mean time to union
Complications Malunion - plantar flexion > 50 Malunion - dorsiflexion > 50
Shortening > 10 mm
1 (4.3%) 3 (13%) 0 (0%) 1 (4.3%)
Ann R Coll Surg Engl 2002; 84
FORSTER
FOREFOOT PLASTER OR WOODEN SOLED SHOES - MITCHELL'S OSTEOTOMY FOR HALLUX VALGUS
Table 3 Changes in symptoms after Mitchell's osteotomy
Table 2 Forefoot score results
Forefoot plaster Mean follow-up 8.7 months
Forefoot score Pain
Wooden soled shoe 10.4 months
Forefoot plaster
Functional restriction
None 17 (58.6%) Mild 10 (34.5%) Moderate 2 (6.9%) Severe 0
None 16 (80%) Mild 3 (15%) Moderate 1 (5%) Severe 0
None 24 (82.8%) Mild 5 (17.2%)
None 18 (90%) Mild 0 Moderate 2 (10%) SevereG
Tender callus
None/mild 16 (80%)
Alignment
Severe 0
Moderate 4 (20%) Severe 0
Tender callus
Present 9 (31%)
Present 7 (35%)
Stiffness
Alignment
Acceptable 26 (89.7%) Acceptable 20 (100%) Not acceptable 3 (10.3%) Not acceptable 0
Stiffness
Present 9 (31%)
Functional restriction
Moderate 0 Severe 0 Footwear restriction
None/mild 21 (72.4%) Moderate 8 (27.6%)
62.7 Mean total forefoot score
Present 5 (25%)
Better Same Worse Better Same Worse Better Same Worse Better Same Worse Better Same Worse Better Same Worse
Pain
Footwear restriction
23 (79.3%) 3 (10.3%)
3(10.3%) 22 (75.9%) 4 (13.8%o) 3 (10.3%)
23 (79.3%) 4 (13.8%) 2 (6.9%) 15 (51.7%) 11 (37.9%) 3 (10.3%) 25 (86.2%) 2 (6.9%) 2 (6.9%)
10 (34.5%) 13 (44.8%) 6 (20.7%)
Wooden soled shoe 19 (95%) 0 1 (5%) 14 (70%) 4 (20%) 2 (10%) 14 (70%) 4 (20%) 2 (10%) 8 (40%) 8 (40%) 4 (20%) 20 (100%) 0 0 7 (35%) 10 (50%) 3 (15%)
Table 4 Patient satisfaction
66.8
Forefoot plaster
Wooden soled shoe
26 (89.7%7o) 1 (3.4%) 2 (6.9%)
19 (95%) 1 (5%)
28 (96.6%)
20 (100%)
Would you have the operation again?
Table 1. There was no statistically significant difference between the 2 groups for any of the variables. The two groups were comparable for age, indication for surgery, grade of surgeon operating and severity of the hallux valgus. There was no statistically significant difference between the two groups for time immobilised, time to union, malunion, shortening, metatarsalgia, superficial infection or recurrence. No patient suffered overcorrection, avascular necrosis, non-union, deep infection or deep vein thrombosis. More patients in the forefoot plaster group had malunion or shortening >10 mm on X-ray. All patients having forefoot plasters complied. Two patients who were given wooden soled shoes were not wearing them at their first out-patient visit. This did not affect their outcome adversely. One patient was changed from a wooden soled shoe to a forefoot plaster for severe pain. This gives a 87% compliance. We were able to contact 33 of the 43 patients by telephone, giving a 76.7% response. All the patients contacted agreed to answer the questions. The results of the forefoot score are summarised in Table 2. No statistically significant difference could be demonstrated between the two groups using the chi-squared test. The mean total forefoot score, the percentage of patients who were pain-free and the percentage of patients with acceptable alignment was greater in the group treated with the wooden soled shoe. Ann R Coll Surg Engl 2002; 84
Yes No Don't know
Are you satisfied with the operation? Yes No Don't know
1 (3.4%)
As part of the questionnaire, the patients were asked whether each symptom covered by the forefoot score had been improved, worsened, or unchanged by the operation. These results are summarised in Table 3. No statistically significant difference could be shown between the two groups using the chi-squared test. More patients treated with the wooden soled shoe showed improvement in their pain and the alignment of their hallux. Patient satisfaction was assessed by asking the two questions in Table 4. Patient satisfaction was high in both groups: 96.6% of the forefoot plaster group and 100% of the wooden soled shoe group were satisfied with the operation. This difference was not statistically significant.
Discussion
The results of both groups in this study are good. The patient satisfaction is high in both groups and comparable 45
FORSTER
FOREFOOT PLASTER OR WOODEN SOLED SHOES - MITCHELL'S OSTEOTOMY FOR HALLUX VALGUS
to previous studies.24 Patients in either group had a similar mean correction and there was no significant difference in complications between the two groups. Patients in the forefoot plaster group suffered more postoperative pain and were more likely to be unhappy with the postoperative alignment, but this was not statistically significant. There is wide variation in the postoperative management of patients after Mitchell's osteotomy Intemal fixation has been suggested as a means to early mobilisation without plaster.8 Mitchell described the use of padded tongue depressors for splintage.2-3 These were placed on the plantar, medial and dorsal surface of the hallux and arranged to hold the toe overcorrected and with 50 of plantar flexion. These were held in position with a bandage and left undisturbed for 10 days. After this, a below knee walking cast was used until the fracture had united (at least 4 weeks). Wilson, when reporting his osteotomy, recommended a below-knee walking plaster for 8 weeks postoperatively.9 A postoperative plaster is also recommended by some experts.1-02 Wooden soled shoes are usually used following soft tissue procedures or when internal fixation is used to stabilise the bone fragments.10 Below-knee plasters and forefoot plasters have been compared following Wilson's osteotomy.13 There was no significant difference between the two groups, leading the authors to conclude a forefoot plaster was sufficient postoperative support. Below-knee plasters and forefoot plasters have not been compared following Mitchell's osteotomy. The forefoot Scotchcasts are expensive, costing £15 each. At least 2 are used for each foot treated. The cost of the initial plaster of Paris U slab and dressings is £1.72. This gives a cost per foot of £31.72. The wooden soled shoes cost £5.80 and can be re-used. The dressing in this group cost 72p and are changed an average of 3 times. Without re-use, the cost per foot for the wooden soled shoe is £7.96. This represents a large possible saving. Plaster of Paris casts could be used (to reduce cost) but they take 24 h to dry and harden. This would delay mobilisation and increase hospitalisation leading to increased costs. The ease of removing the wooden soled shoe could mean that compliance is a problem. The temptation for patients to
46
remove the shoe and walk without it must be great. This is only likely to occur late when the osteotomy is beginning to heal and is no longer painful. We have no evidence that this causes any problems. In this study, 2 patients did not fully comply, but they reported no problems. Conclusions In this study, there was no statistically significant difference between the 2 groups for any of the variables tested. Both techniques gave similar good results. This suggests that a forefoot plaster following Mitchell's osteotomy is unnecessary and the simpler technique using a removable wooden soled shoe could be used as an altemative. References 1. Reverdin J. De la deviation en dehors du gros orteil et de son traitement chirugical. Trans Int Med Congress 1881; 2: 408-12. 2. Hawkins FB, Mitchell CL, Hedrick DW. Correction of hallux valgus by metatarsal osteotomy. J Bone Joint Surg 1945; 27: 387-94. 3. Mitchell CL, Fleming JL, Allen R, Glenney C, Sanford GA. Osteotomybunionectomy for hallux valgus. J Bone Joint Surg Am 1958; 40: 41-60. 4. Blum JL. The modified Mitchell osteotomy-bunionectomy: indications and technical considerations. Foot Ankle Int 1994; 15: 103-6. 5. Glynn MK, Dunlop JB, Fitzpatrick D. The Mitchell distal metatarsal osteotomy for hallux valgus. J Bone Joint Surg Br 1980; 62: 188-91. 6. Wu KK. Mitchell's bunionectomy and Wu's bunionectomy: a comparison of 100 cases of each procedure. Orthopaedics 1990; 13: 1001-7. 7. Kitaoka HB, Holiday Jr AD. Metatarsal head resection for bunionette: long term follow-up. Foot Ankle Int 1991; 6: 345-9. 8. Briggs TWR, Smith P, McAuliffe TB. Mitchell's osteotomy using internal fixation and early mobilisation. J Bone Joint Surg Br 1992; 74: 137-9. 9. Wilson JN. Oblique displacement osteotomy for hallux valgus. J Bone Joint Surg Br 1963; 45: 552-6. 10. Coughlin MJ. Hallux valgus. J Bone Joint Surg Am 1996; 78: 932-66. 11. Mann RA, Coughlin MJ. Adult hallux valgus. In: Mann RA, Coughlin MJ. (eds) Surgery of the Foot and Ankle, 6th edn. Chicago, IL: Mosby, 1993; 167-297. 12. Richardson EG, Donley BG. Disorders of the hallux. In: Canale ST. (ed) Campbell's Orthopaedics, 9th edn. Chicago, IL: Mosby, 1998; 1652-5. 13. Ramanathan EBS, Haywood-Waddington MB. Plaster support after Wilson's osteotomy for hallux valgus. J Bone Joint Surg Br 1988; 70: 412-4.
Ann R Coll Surg Engl 2002; 84
