Clinical outcome of hallux valgus corrective surgery

Chiu SY, Fu WK, Ip FK

Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.

ABSTRACT

We retrospectively reviewed the results of 32 patients (45 feet), with hallux valgus deformity of whom were corrected by operative procedures (19 feet with distal chevron osteotomy and 26 feet with distal soft tissue procedure [DSTP] and basal osteotomy) in our hospital. Patients were followed for 18 to 63 (mean 32) months. The mean preoperative and postoperative hallux valgus angle (HVA) were 33.7o and 20.6o respectively. The mean preoperative and postoperative intermetatarsal angle (IMA) were 13.7o and 8.3o respectively. Only 46.9% of our patients were totally satisfied with the operation. Of the patients, 68.8% stated that, given the identical circumstances, they would have the operation again; 56.3% had pain improvement after the operation. The mean HVA improvement was found to be associated with greater satisfaction postoperatively. Patients with younger age and less degeneration of the first metatarsophalangeal joint (MTPJ) in preoperative radiographs would have better pain relief after the operation. Four recurrence of hallux valgus, one hallux varus, one wound infection and one osteotomy site nonunion were encountered. In conclusion, our results were comparable to other reported series. We recommend further studies in identifying the favourable and adverse risk factors to hallux valgus corrective surgery.

Key Words: Basal osteotomy, Chevron osteotomy, Clinical outcome, Distal soft tissue procedure,

Hallux valgus

中文摘要

   趾外翻矯形手術的臨床研究

趙善揚、傅偉基、葉富強

本院自199311月開院至19976月,共治理32例45   趾外翻矯形手術。十九外翻患足接受了遠端蹠骨截骨術,26隻外翻患足接受了遠端軟織重整及近端截骨術。經1863個月的隨診,外翻角平均值於術前為33.7o,術後為20.6o 。二蹠間角平均值於術前為13.7o,術後為8.3o

手術後效果完全滿意的只有46.9%,術後足部疼痛減少的有56.3%。術後外翻角的減少與病者術後的滿意程度有關係。年輕的f者與術前第一蹠趾關節退化較少的病者,在術後疼痛緩較多。併發症:四足再次出現外翻,內翻、傷口感染、截骨端未能骨癒合各一。

INTRODUCTION

The treatment of hallux valgus deformity includes nonoperative and operative aspects. Various surgical procedures had been reported in the literature.1-6,8-11,13,14 Clinical and satisfaction outcomes were reported and analysed by some authors.3,6,7,9,10,12,14 The results varied a lot.

This is a retrospective review of the results of adult Chinese patients (all above 18 years old) who had received corrective operation of hallux valgus deformity in our hospital. The objectives of this study were to assess clinical outcomes and patients' satisfaction of the operative treatment of hallux valgus and to identify the risk factors that were associated with poor clinical outcome postoperatively.

 

PATIENTS AND METHODS

Between November 1993 and June 1997, 38 adult patients (52 feet) received hallux valgus corrective operation in our hospital. Four patients had emigrated to other countries, two patients had lost contacts. This left 32 patients with 45 feet for analysis.

Conservative treatments were tried prior to operations if indicated. Treatment included shoe wear modification, padding, activity restriction and analgesics.

Indications for operative treatment included failure to control symptoms (eg pain, difficulties in shoe wear, etc) with conservative treatment and advance deformity.

A standard protocol was followed in choosing the type of operation for individual patient.11 Chevron distal osteotomy was performed to deal with mild hallux valgus deformity (hallux valgus angle [HVA] < 30o and intermetatarsal angle [IMA] < 15o). Distal soft tissue procedure (DSTP) and basal osteotomy were done to correct severe hallux valgus deformity (HVA > 30o and IMA > 15o).

The patients were allowed heel walking for 6 weeks after the operation. Gradual weight-bearing was then continued. All patients having DSTP with basal osteotomy had their feet taped by medical staff weekly or twice weekly for 6 weeks.

The duration of follow-up after operation ranged from 18 to 63 months, averaging at 30 months. All patients were interviewed by phone. All interviews were conducted by one single investigator who had never seen the patients. A standard questionnaire was used to assess patient's preoperative and postoperative symptoms and functional status. Assessments of patient's pain, activities of daily living, participation in recreational and sports activities, walking distance, the use of walking aids, problems of shoe wearing, overall satisfaction and complications were included in the questionnaire.

Preoperative and postoperative weight-bearing dorsoplantar and lateral X-rays of the feet were taken. The latest postoperative X-ray (ie at least 18 months after the operation) was measured. HVA, IMA, congruency and degeneration of the first metatarsophalangeal joint (MTPJ), and position of tibial sesamoid bone relative to the first metatarsal head were assessed. The HVA is the angle subtended by a line drawn through the centre of the first metatarsal head and the middle of its base and a line along the long axis of the proximal phalanx. The IMA is the angle subtended by a line drawn through the centre of the first metatarsal head and the middle of its base, and a line parallel to the second metatarsal shaft (Fig. 1). The positions of the medial sesamoids were classified as lateral, central or medial in relation to a line drawn along the centre of the longitudinal axis of the first metatarsal (Fig. 2A , B).15 All measurements were done by the same investigator to prevent interobserver bias.

The correlation between subjective and radiographic findings was analysed with unpaired two-tailed student t test. The correlation between preoperative variables and postoperative outcomes was analysed with ANOVA test, p value less than 0.05 was regarded as statistically significant.

RESULTS

For the 32 patients analysed, three were male and 29 were female. Among the 45 feet operated, 28 were the right feet and 17 the left.

Nineteen feet received chevron osteotomy of the distal first metatarsal. Twenty-six feet had modified McBride DSTP and basal osteotomy of the first metatarsal. Twenty feet had lesser toes operated together with the first ray surgery.

Radiographic Evaluation

The preoperative HVA ranged from 18o to 57o with a mean of 33.7o. The postoperative HVA ranged from -10o to 46o with a mean of 20.6o. The mean improvement was 13.1o.

The preoperative IMA ranged from 4o to 26o with a mean of 13.7o. The postoperative IMA ranged from 2o to 17o with a mean of 8.3o. The mean improvement was 5.4o (Table 1).

The preoperative and postoperative radiographic findings of our 19 chevron osteotomy and 26 DSTP with basal osteotomy were shown in table 2.

Preoperatively, the numbers of tibial sesamoids located at medial, central and lateral position were seven, 17 and 21 respectively. In the postoperative X-ray, the number of tibial sesamoids located at medial, central and lateral positions were 12, 20 and 13 respectively. Of all operated feet, 26.6% had significant improvement of the position, ie the position changed from lateral position to central or medial position, or from central position to medial position after the operation.

Of the 45 feet, 13 had congruent joint preoperatively. Of the remaining 32, 10 with incongruent joints (31.3%) had congruent joint after the operation.

The first MTPJ degenerative changes were classified as no degeneration, mild degeneration (mild sclerosis of joint surface), and severe degeneration (narrowing of cartilage space, presence of osteophytes and cystic changes). Of the 45 feet, 30 had no or mild degenerative changes of the first MTPJ in preoperative radiographs. 

Subjective Findings

The severity of pain was categorised according to the use of analgesics. The severity of foot pain preoperatively and postoperatively was compared. Of the patients, 56.3% experienced less pain postoperatively, 40.6% experienced similar magnitude of pain, whereas 3.1% (one patient) had more pain.

For the walking distance, the duration of walking that the patients could tolerate was assessed and compared, 68.8% of them had improvement postoperatively, 25% no improvement and 6.3% deteriorated.

Summary of the subjective findings for chevron osteotomy, DSTP with basal osteotomy were shown in table 3.

About the overall satisfaction with the results of the operation, 46.9% were totally satisfied with the operation, 40.5% were satisfied but with reservation and 12.6% were not satisfied. Results of patients with DSTP plus basal osteotomy and chevron osteotomy were shown in table 4. The latter two groups were classified as the "less satisfied" group in the subsequent analysis and discussion.

Among the patients, 68.8% (nine from chevron osteotomy group and 13 from DSTP plus basal osteotomy group) would have selected the same operation, given the identical situation, if they were allowed to choose again; while 31.2% (four from chevron osteotomy group and six from DSTP and basal osteotomy group) would not.

Complications in this series included: four recurrences of hallux valgus (two from DSTP with basal osteotomy and two from chevron osteotomy), one hallux varus after DSTP with basal osteotomy, one minor wound problem after DSTP with basal osteotomy, and one nonunion of the chevron osteotomy site.

Correlation Between Radiographic and Subjective Findings

The mean HVA improvement for patients who were satisfied with the operation and those who were less satisfied with the operation were 17.5o and 9.6o respectively. The difference was statistically significant (p = 0.015). The mean IMA improvement for patients who were satisfied and for those who were less satisfied with the operation were 6.8o and 4.3o respectively. The difference was not statistically significant (p = 0.127) (Table 5). The mean postoperative HVA for patients who were satisfied and for those who were not satisfied were 17.1o and 23.4o respectively. The difference was statistically significant (p = 0.035). The difference of the mean postoperative IMA for patients who were satisfied and for those who were less satisfied was not statistically significant.

The relationship between the mean HVA and IMA improvement together with postoperative pain improvement was analysed. For the group of patients with postoperative pain improvement, the mean HVA improvement after the operation was 12o. For those with no pain improvement, the mean HVA improvement was 8.7o. The difference was not statistically significant. The mean IMA improvement for those patients with postoperative pain improvement and those without pain improvement were 6.4o and 4.7o respectively. The difference was not statistically significant either (Table 6).

When the results were analysed separately for the group of patients receiving Chevron osteotomy and for another group of patients receiving DSTP with basal osteotomy, the relationship between radiological findings and subjective findings (ie pain, the degree of postoperative satisfaction) were all statistically not significant (Table 5,6).

Association of Preoperative Variables and Postoperative Subjective Outcome

No preoperative variables were found to be related to postoperative outcome statistically. Namely, preoperative HVA and IMA were not associated with postoperative pain relief or satisfaction. However, some patterns worth being observed. Firstly, a large number of patients with no or mild preoperative degenerative changes of the first MTPJ had postoperative pain improvement, but a smaller number of them were satisfied with the operation (Fig. 3, 4, ). Secondly, in order to study "age" as a preoperative variable, patients were divided into four age groups for statistical analysis. A large number of the younger patients had pain relief postoperatively, but some of them were less satisfied with the operation (Fig. 5, 6).

Furthermore, there was no statistical significance between postoperative pain relief and the degree of satisfaction (Table 7).

 

DISCUSSION

The overall postoperative mean HVA was 20.6o. The mean correction of HVA and IMA were 13.5o and 5.7o after basal osteotomy. The mean correction of HVA and IMA after distal chevron osteotomy were 10.8o and 4.6o respectively. In the literature, after basal osteotomy, the HVA corrected was in the range from 15o to 23o.9,12,13 The reported IMA corrected was in the range from 6o to 10o.9,12,13 After chevron osteotomy, the reported hallux angle correction and IMA correction were 10o - 12o and 4o - 5o respectively.5,7,10,14 Our results were comparable to those reported in the literature.

In our study, more than half of the patients experienced less pain after the operation. Concerning the degree of satisfaction, only about two thirds of our patients would like to have the operation again, whereas the remaining one third would not do so. The degree of satisfaction was relatively low in contrast to other published studies.5-10,12,14 The reasons were the presence of complications, inability to meet the patients' expectation and long postoperative rehabilitation course. Of the 32 patients, 10 reported that the early postoperative "recovery period" was too long. During the period, they had limitation in walking and hence their earning abilities were affected.

Significant number of complications after the operative treatment developed. Of the 45 feet, four still had the hallux valgus deformity after the operation, two had recurrence after chevron osteotomy, and two had persistence of the hallux valgus deformity after basal osteotomy and DSTP. All were due to inadequate correction. One of them received a second operation and the result was satisfactory afterward. One recurrence was due to inadequate postoperative dressing and another was because of the inappropriate use of narrow shoes postoperatively. In the literature, hallux valgus recurrence rate was 10% after chevron osteotomy1,5 and 3.7% after DSTP with basal osteotomy.9

One hallux varus deformity (the HVA less than 0o in dorsoplantar X-rays) after modified McBride and basal osteotomy developed. The HVA was -10o. The reported incidence of hallux varus deformity after basal osteotomy were 8% to 12%.3,9 Our patient was asymptomatic despite the deformity.

One nonunion developed after chevron osteotomy. However, the patient refused to have further operation. One patient had minor wound infection in one of her operated feet. The condition was successfully treated with daily dressing and antibiotics.

The lesser degree of residual deformity in terms of residual postoperative HVA and the greater degree of HVA improvement was associated with higher degree of satisfaction statistically but was not associated with better pain relief. Improvement of HVA means a better contour of the foot and better biomechanics of the foot which would increase the overall satisfaction rate.

We were unable to identify any preoperative variables statistically associated with postoperative pain relief and satisfaction. It might be attributed to our small sample size. A large number of our young patients and those patients with no or mild preoperative degenerative changes of their first MTPJ had pain relief but were less satisfied with the operation. There were two inferences from these observations. Firstly, pain relief did not necessarily represent satisfaction. Secondly, besides pain relief, young patients might be more concerned about other aspects such as the contour of the foot, the lengthy postoperative rehabilitation, the short- and long-term functional status postoperatively. A detailed preoperative counseling and understanding of patients' concern is considered necessary.

A major criticism of our study is that our patients are heterogeneous in age, degree of deformity and disability. In addition, because we collected our data by phone, some information, such as the exact sites of pain, could not be analysed. Furthermore, this is a retrospective review of a small number of patients. Hopefully, a prospective study can be conducted in the future for a larger number of patients after corrective operation of hallux valgus deformity.      

ACKNOWLEDGEMENT

The authors would like to thank Dr. MT Ng of the Department of Surgery, Alice Ho Miu Ling Nethersole Hospital, Tai Po, Hong Kong, to assist in the review of the patients.

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The Authors

CHIU Shin-Yeung, MBBS, FRCSEd, Medical Officer, Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.

FU Wai-Kee, FRCSEd, FHKAM (Orth Surg), Senior Medical Officer, Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.

IP Fu-Keung, FRCSEd, FHKAM (Orth Surg), Consultant, Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.