Jackson and Waugh, in 1961, reported that proximal tibial osteotomy is a reliable procedure for the relief of pain and the restoration of function in patients who have osteoarthrosis of the knee, and this finding has been supported by several other authors3-5,8,11,13,19. Coventry studied the long-term results of proximal tibial osteotomy performed in 213 patients for osteoarthrosis of the knee and reported that 130 patients (61 per cent) had less pain and 138 patients (65 per cent) had better function ten years after the procedure. Matthews et al. performed a survival analysis of forty patients who had been managed with a proximal tibial osteotomy and found that the probability of continued useful function was 86 per cent at one year, 64 per cent at three years, 50 per cent at five years, and 28 per cent at nine years. The reported deterioration of the results of proximal tibial osteotomy increases the difficulty of selecting the appropriate treatment of osteoarthrosis of the knee in active patients who are less than sixty years old.
In the present study, we tried to determine the highest level of activity that actually had been achieved after a proximal tibial osteotomy, whether the patients had achieved the desired level of function, and whether a total knee arthroplasty would have been a better choice.
*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.
†Read at the Annual Meeting of The American Academy of Orthopaedic Surgeons, New Orleans, Louisiana, March 1, 1994.
‡187 Thomas Johnson Drive, Frederick, Maryland 21702.
§Insall Scott Kelly Institute for Orthopaedics and Sports Medicine, Beth Israel Medical Center, North Division, 170 East End Avenue at 87th Street, New York, N.Y. 10128.
We evaluated the results of thirty-seven proximal tibial osteotomies in thirty-four patients. This cohort was part of a group of seventy-eight patients who had had a proximal tibial osteotomy between 1979 and 1991. Our criteria for the performance of an osteotomy were more general in 1979 because of our uncertainty regarding the long-term results of total knee arthroplasty. Today, we seldom recommend osteotomy for women because of concerns about the cosmetic effect of the operation. From the original group of seventy-eight patients, therefore, we excluded twenty-four women, fifteen men who had been more than sixty years old at the time of the operation, and three patients (all men) who had died. Of the thirty-six patients who met our criteria for inclusion, two were lost to follow-up. The study group therefore included thirty-four patients, all of whom were men. The average age of the patients at the time of the operation was forty-nine years (range, twenty-eight to sixty years), and the average deformity was 10 degrees (range, 0 to 20 degrees) of varus. The diagnosis was degenerative osteoarthrosis for twenty-two knees, post-traumatic osteoarthrosis for twelve, and osteochondritis dissecans for three.
The senior one of us (J. N. I.) performed all of the operations with use of a previously described technique6. A closing-wedge osteotomy was performed, and correction was maintained with an above-the-knee cast (twenty-nine knees) or with fixation with a blade-plate (eight knees). There were no specific indications for the use of internal fixation.
After an average duration of follow-up of eight years (range, two to fourteen years), the patients were evaluated with use of a detailed questionnaire to determine the highest level of activity that had been achieved after the proximal tibial osteotomy. To avoid bias by the operating surgeon or by the patient, who may try to please the surgeon with satisfactory responses, the operating surgeon did not participate in the interviews or the administration of the questionnaire. The functional results were evaluated according to the scoring system of Tegner and Lysholm (Table I), in which the level of performance in manual labor and recreational sports activities is rated on a scale from 0 points (complete disability) to 10 points (the ability to perform at the level of an elite professional athlete).
In an earlier report7, one of us (J. N. I.) and colleagues noted deterioration of the clinical results of proximal tibial osteotomy with time and with increasing age of the patient. In the present study, therefore, we recorded the highest level of activity (peak performance) that had been achieved at any time after the osteotomy and not necessarily the level that was observed at the time of the latest evaluation.
The patients also completed the questionnaire by providing a yes-or-no response to a number of questions regarding the ability to walk one mile (1.6 kilometers), to go up and down stairs normally, to stand for four hours or more, to kneel, to climb a ladder, to perform manual labor before and after the operation, to participate in singles or doubles tennis, to ski downhill or cross-country, to ride a stationary or a conventional bicycle, to run, to jog, and to participate in other sports. They also were asked if activity caused pain or swelling and if they would have the operation again given the same circumstances. They then were asked to grade the efficacy of the operation in relieving pain and improving function on a scale from 0 to 100 points, with 0 implying failure and 100 implying a successful result.
The patients were divided into two groups on the basis of their preoperative activity score22: the patients in Group I had a score of 4 points or less and those in Group II, a score of 5 points or more. The results were analyzed with the Fisher exact test, and the level of significance was p < 0.05.
Group I comprised twelve patients (fourteen knees) who were an average of forty-eight years old (range, thirty-one to sixty years old) at the time of the index procedure (Table II). The preoperative diagnosis was post-traumatic osteoarthrosis for six patients, osteoarthrosis for five, and osteochondritis dissecans for one. Two patients had a bilateral procedure. The average deformity was 11 degrees (range, 5 to 20 degrees) of varus preoperatively and 10 degrees (range, 5 to 15 degrees) of valgus postoperatively. The average preoperative activity score of Tegner and Lysholm was 3.2 points (2, 3, or 4 points), and the average postoperative score was 2.8 points (range, 1 to 4 points). Eight patients had no change in their score postoperatively, and four had a decrease in their score (Table II).
Group II comprised twenty-two patients (twenty-three knees) who were an average of fifty years old (range, twenty-eight to sixty years old) at the time of the index operation (Table II). The preoperative diagnosis was osteoarthrosis for fifteen patients, post-traumatic osteoarthrosis for six, and osteochondritis dissecans for one. One patient had a bilateral procedure. The average deformity was 7 degrees (range, 5 to 15 degrees) of varus preoperatively and 9 degrees (range, 5 to 17 degrees) of valgus postoperatively. The average preoperative activity score of Tegner and Lysholm was 6.5 points (range, 5 to 8 points), and the average postoperative score was 5.9 points (range, 2 to 8 points). Postoperatively, twelve patients had no change in the activity score and ten had a lower score. Of the ten who had a lower score, five had a decrease to a score of 4 points or less and five continued to function at a level of 5 points or more (Table II).
A comparison of the ability of the patients in each group to participate in activities of daily living showed that the only significant difference was in the ability to stand for four hours or more; seven patients in Group I and twenty patients in Group II were able to do so (p = 0.03). Ten patients in Group I and twenty-one patients in Group II were able to walk at least one mile (1.6 kilometers) (p = 0.28), nine patients in Group I and twenty-one patients in Group II were able to walk up stairs normally (p = 0.12), eight patients in Group I and nineteen patients in Group II were able to walk down stairs normally (p = 0.18), four patients in Group I and thirteen patients in Group II were able to kneel (p = 0.14), and ten patients in Group I and twenty patients in Group II were able to climb a ladder (p = 0.44).
We combined the two groups for the analysis of the ability to participate in sports and to perform manual labor as several patients in each group had not performed these activities preoperatively and had no intention of performing them postoperatively. The numbers were too small for us to draw any meaningful conclusions. Twenty-six of the thirty-four patients regularly performed manual labor that necessitated climbing, lifting, pushing, or pulling. This manual labor included activities such as painting, laying tile or carpet, paneling, carpentry, daily housekeeping, gardening, lawn-mowing, brick-laying, and construction work.
Fifteen patients played tennis preoperatively, and thirteen continued to do so postoperatively (nine played singles and four played doubles tennis). This finding was not related to age. Four additional patients participated in squash, racquetball, or handball, and one patient played competitive badminton.
Eleven patients skied preoperatively. Of the nine patients who continued to ski postoperatively, six skied downhill and three skied both downhill and cross-country; one of these nine also was able to water-ski. All nine patients were able to ski at their preoperative level.
Preoperatively, fourteen patients jogged ten minutes or more three times a week; ten continued to do so postoperatively. Eight of these ten patients were able to run strenuously.
Thirty patients were able to ride either a stationary or a conventional bicycle preoperatively, and twenty-six were able to do so postoperatively. Twenty-one of these patients bicycled vigorously for ten minutes or more three times a week.
Eleven patients had pain with activity: the pain was mild in nine and moderate in two. Six of the thirty-four patients had swelling of the knee with activity.
The average patient-satisfaction score was 84 of a possible 100 points. Twenty-eight patients (nine from Group I and nineteen from Group II) stated that they would have the operation again; this finding was not significant (p = 0.35).
Eight patients had at least one additional operative procedure. Six had a total knee replacement at an average of seven years (range, two to thirteen years) after the osteotomy. One patient had reconstruction of the anterior cruciate and medial collateral ligaments because of recurrent instability, and another had a fibular osteotomy because of proximal migration of the fibular head.