Long-Term Results of Watson-Jones Tenodesis of the Ankle. Clinical and Radiographic Findings After Ten to Eighteen Years of Follow-up*

SUGIMOTO, KAZUYA M.D.†; TAKAKURA, YOSHINORI M.D.‡; AKIYAMA, KOHICHI M.D.‡; KAMEI, SHIGERU M.D.‡; KITADA, CHIKARA M.D.§; KUMAI, TSUKASA M.D.‡, KASHIHARA, NARA, JAPAN

Journal of Bone & Joint Surgery - American Volume:
Article
Abstract

Thirty-seven chronically unstable ankles in thirty-six patients were operated on with use of a Watson-Jones tenodesis. Thirty-four ankles (thirty-three patients) were followed for a mean duration of thirteen years and eight months (range, ten to eighteen years) after the operation. There were nine male and twenty-four female patients. The mean age of the patients was thirty-one years (range, fourteen to fifty-seven years) at the time of the operation and forty-four years (range, twenty-eight to seventy years) at the time of the latest follow-up. At the time of the most recent follow-up evaluation, twenty-seven patients (twenty-eight ankles) were examined directly by one of us and twenty-five patients (twenty-six ankles) also were evaluated radiographically. The other six patients were interviewed, with use of a questionnaire, by telephone. Of the thirty-four ankles, nineteen had an excellent result (grade 1), eleven had a good result (grade 2), three had a fair result (grade 3), and one had a poor result (grade 4) according to the rating system of Good et al. The mean score (and standard deviation) on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society for the twenty-eight ankles that were examined directly by one of us was 90 ± 9.3 points (range, 68 to 100 points). Progression of an exostosis at the edge of the joint was detected in eighteen (69 percent) of the twenty-six ankles that were examined radiographically, but narrowing of the joint space was not seen in any ankle. No relationship was detected between the clinical results and radiographic osteoarthrotic changes or the duration of follow-up. The results did not deteriorate over the long term.

Author Information

†Department of Orthopaedic Surgery, Saiseikai Nara Hospital, 4-643 Hchijo, Nara-shi, Nara 6308145, Japan.

‡Department of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara-shi, Nara 6340813, Japan.

§Department of Orthopaedic Surgery, Saiseikai Chuhwa Hospital, 323 Abe, Sakurai-shi, Nara 6330054, Japan.

Article Outline

Chronic lateral instability of the ankle sometimes can be treated by suturing of the torn lateral ligament2,9,10,14, but tenodesis or reconstruction with use of an autogenous tendon graft has been used in most published series1,3-6,8,12,13,16,17,20,22,24,26,27,30,31,33-37. Substitutes for the ligament have included the peroneus longus37 or brevis tendon1,3-6,8,12,13,17,20,22,24,31,33-36, the Achilles tendon31, the plantaris tendon27, and the periosteal membrane7,23,29,38. Of these autogenous grafts, a free or partly attached peroneus brevis tendon is the most popular choice for reconstruction of the lateral ligament. However, most tenodeses in which the peroneus brevis tendon is used do not result in an anatomical reconstruction with regard to the isometry of the ligament, and these procedures may not restore the normal stability or movement of the hindfoot.

The Watson-Jones tenodesis is one of the standard procedures that involve use of the peroneus brevis tendon. It consists of three parts. The first part of the tenodesis is performed between the fibula and the fifth metatarsal and crosses the calcaneofibular ligament at a right angle. The second and third parts are done between the fibula and the talus and follow almost the same route as the anterior talofibular ligament. Thus, this procedure is partly anatomical and partly nonanatomical.

The short-term results of the original or modified Watson-Jones procedure have been reported as satisfactory in most patients6,12,20,36,37. However, in 1984, Van der Rijt and Evans reported that the results deteriorated seven to ten years after the procedure34. The mean duration of follow-up in their series was sufficient, but the number of patients (nine) was too small to provide a basis for an evaluation of the Watson-Jones procedure. Hoy and Henderson, in the most recent report of the results of the Watson-Jones tenodesis of which we are aware, found no relationship between the duration of follow-up and the results13. This controversy has not been resolved, and the recent trend has been toward delayed primary suture or suture with augmentation10,14.

In the current report, we describe the clinical results and radiographic changes in the ankle and subtalar joints ten to eighteen years after a Watson-Jones tenodesis.

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Materials and Methods

Patients

Thirty-seven chronically unstable ankles in thirty-six patients were operated on at Nara Medical University with use of a Watson-Jones tenodesis between August 1979 and May 1989. Three patients (three ankles) subsequently were lost to follow-up, after less than three years, because they had moved more than twice; these patients were not included in the study, although their short-term results were excellent.

The remaining thirty-four ankles (thirty-three patients) were followed for a mean duration of thirteen years and eight months (range, ten to eighteen years). There were nine male and twenty-four female patients. The mean age of the patients at the time of the operation was thirty-one years (range, fourteen to fifty-seven years). Seventeen ankles were injured as a result of a fall down stairs or on uneven ground; eleven, during sports activity; and one, in a motor-vehicle accident. The cause of the injuries of the remaining five ankles was unknown. The mean interval between the injury and the operation was five years and seven months (range, two months to forty years). Preoperatively, all patients had had pain during walking, thirty-two had had giving-way or a feeling of apprehension during sports activity or when walking on uneven ground, and twenty-three had had swelling after activity.

Twelve patients were students, nine were homemakers, eight were desk workers, three were manual laborers, and one was a nurse. Three of the students were competitive athletes, and the other nine were recreational athletes. There were no professional athletes.

At the time of the latest follow-up, twenty-seven patients (twenty-eight ankles) were examined directly by one of us (K. S.) and twenty-five patients (twenty-six ankles) also were evaluated radiographically (Table I). The remaining six patients (six ankles) were interviewed, with use of a questionnaire, by telephone (Table II).

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Operative Technique

The Watson-Jones tenodesis was performed with the patient under lumbar spinal anesthesia, in the decubitus position, and with the affected side up. Three minor modifications were made to the procedure. First, the tenodesis between the fibula and the fifth metatarsal was performed with the ankle and the hindfoot in the neutral position. Second, the two holes that were drilled in the fibula were located close to each other, five to ten millimeters apart. (The superior hole was located at the superior edge of the attachment of the anterior talofibular ligament to the fibula, and the inferior hole was located at the inferior edge of the attachment.) Third, the tendon was sutured to the periosteal membrane at the edges of the holes in the fibula with a 2-0 nylon suture.

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Postoperative Regimen

After the operation, the wound was drained for two days. A below-the-knee cast was worn for four to six weeks (mean, 5.2 weeks), and weight-bearing was not allowed for three weeks. Supervised physiotherapy included range-of-motion exercises of the ankle and the hindfoot and strengthening of the peroneal muscles, performed every day for one week and two or three times a week for the next three weeks. Active exercises of the ankle and the subtalar joint were allowed immediately after removal of the cast, and passive exercises of the hindfoot, performed by a physical therapist, were begun six weeks after the operation. Sports activity was allowed three months after the operation.

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Clinical Evaluation

The preoperative condition of the ankle was graded according to the rating system of Good et al. (Table III)8. Two ankles were grade 2; seventeen, grade 3; and fifteen, grade 4. The clinical results for the twenty-seven patients (twenty-eight ankles) who were examined directly were determined according to the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society15 and the rating system of Good et al.8. The other six patients (six ankles), who were interviewed by telephone with use of a questionnaire, were assessed only with the rating system of Good et al.

At the time of follow-up, the difference in the maximum circumference of the calf between the affected and the contralateral side was measured, and the strength of the peroneal muscles in the affected leg, as measured with use of a manual test, was compared with that in the contralateral leg. The manual test was performed with the patient sitting on the end of the bed and the leg hanging. The examiner held the patient's right (or left) leg with his right (or left) hand and held the patient's forefoot with his left (or right) hand. The patient then was instructed to bring his or her foot from a position of maximum inversion to one of maximum eversion against the resistant force applied manually by the examiner. This was repeated three times for each leg.

Sagittal motion (flexion and extension) and motion of the hindfoot (inversion and eversion) also were measured, on both sides, with use of a goniometer. Sagittal motion was considered to be unrestricted if it was at least 30 degrees and not less than that on the contralateral side, mildly restricted if it was at least 30 degrees but less than that on the contralateral side, moderately restricted if it was between 15 and 29 degrees, and severely restricted if it was less than 15 degrees. Motion of the hindfoot was considered to be unrestricted if it was more than 90 percent of that on the contralateral side, mildly restricted if it was between 75 and 90 percent of that on the contralateral side, moderately restricted if it was between 50 and 74 percent of that on the contralateral side, and severely restricted if it was less than 50 percent of that on the contralateral side.

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Radiographic Evaluation

Anteroposterior and lateral radiographs, with the patient standing, and routine stress radiographs of the ankle were made at the time of follow-up. Narrowing of the joint space, exostosis at the edge of the joint, and any other osteoarthrotic changes were recorded, and these findings were compared with the radiographic findings before the operation (Figs. 1-A, 1-B, 1-C through 1-D). The talar tilt angle and the anterior drawer distance were measured on routine stress radiographs made both before and after the operation. A stress machine was not available at the time of the operation, so stress was applied manually without use of anesthesia. The talar tilt angle was measured with use of stress inversion radiographs according to the method of Rubin and Witten25, and the anterior drawer distance was measured with use of stress anterior drawer radiographs according to the method of Landeros et al.18. To avoid a muscle spasm, which masks instability of the ankle, a steadily increasing force was applied by the lead-gloved hand of the examiner for one-half of a minute. The same method of stress radiography (without a stress machine) was used at the time of follow-up so that we could compare the stress radiographs made before and after the operation. At the latest follow-up evaluation, two women who were examined directly by one of us were pregnant, so radiographs were not made for them. Thus, twenty-six ankles (twenty-five patients) had radiographic evaluation.

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Statistical Analysis

The preoperative and postoperative talar tilt angles and anterior drawer distances were compared with use of a paired t test. The correlations between the score on the ankle-hindfoot scale and the age of the patients at the time of follow-up, the duration of follow-up, and the preoperative duration of the symptoms were determined with use of the Pearson product-moment method followed by the Fisher x-transformation.

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Results

Clinical Results

The mean age of the patients at the time of the most recent follow-up was forty-four years (range, twenty-eight to seventy years). At the time of the latest follow-up, six patients had or had had a problem related to the lower extremity. One patient (Case 10) had had an injury of the anterior cruciate ligament in the ipsilateral knee, which had been treated operatively with an over-the-top repair; one (Case 15) had had a fracture of the ipsilateral fibula nine years after the operation; one (Case 17) had a severe hallux valgus deformity of the ipsilateral foot as well as severe osteoarthrosis of the contralateral ankle that had been treated with a total ankle arthroplasty; one (Case 18) had a Morton neuroma of the ipsilateral foot; one (Case 19) had moderate osteoarthrosis of both knees; and one (Case 21) had a varix of the ipsilateral leg.

Nineteen of the thirty-four ankles had an excellent result (grade 1), eleven had a good result (grade 2), three had a fair result (grade 3), and one had a poor result (grade 4) according to the rating system of Good et al.8. The mean score (and standard deviation) on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society15 for the twenty-eight ankles that were examined directly was 90 ± 9.3 points (range, 68 to 100 points) (Table I). Fifteen ankles had a score of 90 points or more, and four had a score of less than 80 points. With the ankle-hindfoot scale, motion of the hindfoot is evaluated by comparing it with that of the contralateral, normal hindfoot. However, the woman (Case 22) who was operated on bilaterally received the maximum number of points because of good motion of both hindfeet that was comparable with that of the normal hindfeet of the patients in this series.

No relationship was found, with the numbers available, between the score on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society at the time of the latest follow-up and the duration of follow-up (r = 0.099; p = 0.620). However, significant negative correlations were found between the final score and the age of the patient at the time of the operation (r = 0.411; p < 0.05) and the age at the time of the latest follow-up (r = 0.412; p < 0.05). No relationship could be detected between the preoperative duration of the symptoms and the score on the ankle-hindfoot scale at the time of the latest follow-up (r = 0.025; p = 0.9023), with the numbers available.

Nine patients had mild restriction of sagittal motion (flexion and extension) compared with that on the contralateral side, but no patient had moderate or severe restriction. No patient reported an impairment in the ability to squat. Fourteen patients had mild or moderate restriction of motion of the hindfoot (inversion and eversion), and seven of them reported difficulty sitting in the Japanese style.

Weakness of the peroneal muscles of the involved leg was not detected in any patient with the manual test, but eight patients reported transient weakness of these muscles after strenuous activity. Atrophy of the calf muscles on the side of the operation was detected in all but two patients (Cases 17 and 21), both of whom had a specific condition of the leg. The mean decrease in the circumference of the calf was 0.9 centimeter compared with that on the contralateral side.

Of the twelve patients who had been students preoperatively, six became desk workers; two, orthopaedic surgeons; two, homemakers; one, a gymnastics instructor; and one, an engineer. The other patients did not change their jobs after the operation.

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Complications

Six patients (18 percent) had a postoperative complication. Three of these patients had a lesion of the cutaneous nerve; two, a superficial wound infection; and one, a fracture of the lateral malleolus of the affected ankle. No patient had a deep wound infection or septic arthritis. Two patients (Cases 11 and 22) of the three who had a lesion of the cutaneous nerve had involvement of the lateral dorsal branch of the superficial peroneal nerve, and the third (Case 25) had involvement of the sural nerve. The numbness was mild in one of them (Case 22) but intractable in the other two. The fracture of the lateral malleolus (Case 15), which occurred nine years after the tenodesis, was treated nonoperatively with immobilization in a cast at another clinic, but it did not affect the result (Fig. 1-C).

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Radiographic Results

The talar tilt angle improved from a mean of 14 ± 6.0 degrees preoperatively to a mean of 4 ± 3.0 degrees postoperatively. The anterior drawer distance also improved, from a mean of 9 ± 1.9 millimeters preoperatively to a mean of 6 ± 2.2 millimeters postoperatively.

Plain radiographs made before the operation showed an exostosis of the medial malleolus in seven (27 percent) of the twenty-six ankles and an impingement exostosis of the tibia in five ankles (19 percent), but narrowing of the joint space was not observed. At least one exostosis was seen in ten (38 percent) of the twenty-six ankles. All ten ankles had progression of the exostoses after the operation, and eight additional ankles had new formation of at least one exostosis. Plain radiographs made at the time of follow-up showed a medial malleolar exostosis in thirteen ankles (50 percent) (Figs. 1-A, 2-A, and 2-B), an impingement exostosis of the tibia in nine (35 percent) (Fig. 1-B), and an anteromedial exostosis of the talar dome in two (8 percent) (Fig. 1-C). At least one exostosis was seen in eighteen ankles (69 percent), but narrowing of the joint space was still not observed. A subchondral cyst was noted in a sixty-three-year-old woman (Case 11) who had had some osteoarthrotic changes before the operation (Fig. 1-D). We could detect no relationship between the clinical results and the radiographic osteoarthrotic changes.

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Discussion

Many authors have affirmed the value of the Watson-Jones tenodesis for the treatment of chronic lateral instability of the ankle on the basis of the short-term results6,12,20,36,37. Van der Rijt and Evans, in 1984, were the first investigators, to our knowledge, to report unsatisfactory long-term results after a Watson-Jones tenodesis34. In their series of nine patients, who were followed for a mean of twenty-two years, the early, favorable results were found to have deteriorated seven to ten years after the operation. A weakness of that report was the small number of patients. Few papers concerning the results of the Watson-Jones tenodesis subsequently were published. In 1994, Hoy and Henderson reported that they had not found any association between the results of the procedure in thirty patients (thirty-two ankles) and the duration of follow-up (mean, less than five years)13. We do not believe that there have been any reports in which both the number of patients and the mean duration of follow-up were sufficient to allow evaluation of the results of this procedure.

Many different rating systems for evaluation of the results of treatment of instability of the ankle have been used in the studies reported in the literature8,14,15,28. In the current study, we used both the ankle-hindfoot scale proposed by the American Orthopaedic Foot and Ankle Society in 199415 and the subjective grading system reported by Good et al. in 19758. The ankle-hindfoot scale was not intended specifically for the evaluation of instability of the ligaments, but it is conventional and simple to use. The scale consists partially of objective criteria, including motion of the hindfoot. The classic method of rating that was proposed by Good et al. is simpler and is useful for the assessment of patients who are followed with telephone interviews or questionnaires without direct examination. With use of these two rating systems, the results of our study can be compared with data from other studies.

Before beginning this long-term follow-up study, we did not expect such satisfactory results; a high proportion (thirty) of the thirty-four ankles in our series had an excellent or good outcome. This rate is comparable with the short-term results that have been reported after an original or modified Watson-Jones tenodesis: eighteen (90 percent) of twenty ankles in the series of Gillespie and Boucher6, forty-six (94 percent) of forty-nine ankles in the series of Zenni et al.37, and seventeen (81 percent) of twenty-one ankles in the series of Hedeboe and Johannsen12 had a good or excellent result.

Kjærsgaard-Andersen et al. found that the Watson-Jones ankle tenodesis did not restore the normal kinematics of the hindfoot16, and Liu and Baker, in a study of cadavera, reported that the modified Broström procedure produced greater mechanical restraints than did the Watson-Jones procedure19. Liu and Baker stated that the first limb of the tenodesis, from the fifth metatarsal to the fibula, is perpendicular to the anatomical direction of the calcaneofibular ligament and therefore does not play the role of a ligament. However, the mean talar tilt angle in their patients improved after a Watson-Jones tenodesis, which suggests that the first limb of the tenodesis may help to prevent tilting of the talus. Also, the second and third limbs of the tenodesis, between the neck of the talus and the fibula, are parallel to the anterior talofibular ligament. In the current series, we performed the operation in such a way that the second and third limbs of the tenodesis were located parallel and close together, thereby restoring the anterior talofibular ligament. Nevertheless, sagittal mechanical instability was not restored as well, possibly because of elongation or loosening of the tendon graft over the long term.

We found no relationship between the score on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society and the duration of follow-up, and we detected no deterioration of the results. However, significant correlations between the score and the age of the patient were found. Problems with the joints in the lower extremity and the spine increase with age, and walking ability decreases; these factors affect the results. In some of our patients, the score on the ankle-hindfoot scale was in fact affected by osteoarthrosis or an injury of a knee ligament. The use of this type of scale, which contains a subsection related to the patient's ability to walk, makes it difficult to avoid the influence of other diseases of the joints or abnormal neurological conditions.

The mean age of our patients at the time of the operation was almost the same as that of patients in other reports on the results of the Watson-Jones tenodesis. However, at the time of the latest follow-up, ten to eighteen years after the operation, the mean age of our patients was forty-four years, which was greater than the mean age of patients in other reports except that of Van der Rijt and Evans; their nine patients had a mean age of fifty-four years at the time of the latest follow-up, and six had an unsatisfactory outcome34. Those authors thought that the poor results were due to the instability of the ankle; however, we believe that they may have been related to the older age of their patients at the time of follow-up. We do not know why their results differed from ours, but there may have been some minor differences in the details of the operative procedure.

Despite the good clinical results, atrophy of the calf muscles was found in our patients long after the operation. The mean decrease in the circumference of the calf was similar to that reported by Lucht et al.20. We do not know whether the main cause of this decrease is general disuse atrophy of the leg or selected atrophy of the peroneus brevis muscle, which is sacrificed at the time of the operation. Although weakness of the peroneal muscles was not detected with the manual test, eight of our patients described mild weakness of these muscles after walking for a long distance or after strenuous activity. St. Pierre et al. reported that loss of the peroneus brevis tendon did not appear to result in a marked loss of eversion strength and power32.

Minor exostoses, seen in ten of our patients before the operation, represented an early stage of osteoarthrosis. The number of patients who had this finding nearly doubled postoperatively, but no patient had narrowing of the joint space of the affected ankle at the time of the latest follow-up. The increase in the number of patients who had a minor exostosis may have been due to the instability of the ankle even after the operation. There have been a few reports on these exostoses after other operative techniques17,22. Korkala et al.17 reported osteophytes of the ankle after an Evans procedure but found no relationship between the subjective outcome and the presence of osteophytes.

Michelson and Hutchins reported the presence of mechanoreceptors in the lateral ligament of the ankle21. It has not been determined whether these mechanoreceptors can be restored in the repaired or reconstructed ligaments. If the mechanoreceptors are not reproduced in the reconstructed ligaments, minor functional instability due to their absence may cause exostoses.

In the current series of Watson-Jones tenodeses, complications were found in six (18 percent) of thirty-four ankles. This rate is similar to those reported by Van der Rijt and Evans34 (two of nine ankles) and Younes et al.36 (two of ten ankles). Snook et al. reported a higher rate of complications (fourteen of forty-eight ankles) after the Chrisman-Snook operation, although they emphasized that numbness persisted in only four patients30. The high rate of complications associated with these types of operations is due to nerve lesions, caused by the long incision that is needed to obtain the peroneus brevis tendon, which is close to the sural nerve.

In contrast, an anatomical reconstruction such as the modified Broström repair is less invasive than a tenodesis or a reconstruction with use of autogenous tendon graft. Low rates of complications have been reported after anatomical repair and reinforcement operations. Karlsson et al.14 reported one complication (3 percent) in thirty ankles; Gould et al.9, one complication (2 percent) in fifty ankles; and Hamilton et al.11, no major complications in twenty-eight ankles. These low rates of complications and the small operative scars are encouraging, and the recent trend has been toward delayed primary repair or augmented repair. The ideal reconstruction would restore the natural or original anatomy. In order to achieve an anatomical reconstruction, many options must be available to the surgeon because the condition of the injured ligaments varies among patients. Fortunately, the development of suture anchor systems has made anatomical reconstruction easier to perform.

In the near future, reconstruction with use of the peroneus brevis tendon may be replaced by anatomical restoration. If there are no differences in the long-term results between these procedures, we would choose anatomical reconstruction because it is associated with fewer complications and necessitates less extensive exploration. However, the long-term results of anatomical restoration (those seen after a mean duration of more than ten years) have not yet been reported, to our knowledge.

In summary, the long-term results of the Watson-Jones procedure have been reported by several authors, but we are not aware of any previous study in which a sufficient number of patients were followed for a long period. We found that the results of a modified Watson-Jones tenodesis were good; did not deteriorate over the long term; and, although not ideal, were much better than we had expected.

NOTE: The authors thank Hiroshi Yajima, M.D., Hiroshi Iwamoto, M.D., Shigeru Mizumoto, M.D., and Takanori Takaoka, M.D., for their assistance with this study.

*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

Investigation performed at the Department of Orthopaedic Surgery, Nara Medical University, Kashihara

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