Introduction

The bone–patellar tendon–bone autograft (BPTB) and the semitendinosus–gracilis autograft (ST–GR) are the most frequently grafts use for anterior cruciate ligament (ACL) reconstruction. Some surgeons use one graft, by the exclusion of the other, in their standard practice [17], whereas others use both, but with different indications.

Randomised studies suggest that both methods are equally valid [1–3, 8, 13, 19], though some reports have shown that the ST–GR is less effective, especially in competitive sportswomen [4–6, 10, 14, 21].

Over the last 3 years we have established clear indications for the use of these two methods at our sports traumatology and arthroscopic surgery centre, namely BPTB for young persons and sportspeople and ST–GR for older subjects or those less devoted to recreational sports.

This paper describes the outcome of a prospective study designed to show whether both methods, albeit applied in dissimilar groups of patients, would lead to comparable results in terms of subjective and objective stability alone.

Materials and methods

Sixty-one consecutive patients (40 males, 21 females: mean age 32), all engaged in competitive or recreational sports, were enrolled (Table 1). All the subjects did not show any previous knee pathology. They had been operated by the same surgeon and reviewed by another independent surgeon. The same endoscopic technique had been employed [18]. The only differences were between the type of graft and the femoral fixation.

Table 1 Number of patients, age and sex
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In the BPTB group, the patellar tendon was fixed with two titanium or bioabsorbable interference screws (as requested by the patient). In the ST–GR group, the doubled tendons were fixed to the femur with two bioabsorbable cross-pins and to the tibia with a bioabsorbable screw.

The rehabilitation programme was the same [20], the only difference being in the ROM completely regaining in 2 weeks in the BPTB group and in 3 weeks in the ST–GR group. This slight difference, in our opinion, is related to the difference in the type of biological material of the graft to be fixed: tendon or bone.

The components of the groups differed in age and sex according to our indications—namely BPTB: young persons preferably male and/or competitive sportspeople; ST–GR: older patients, preferably female and/or recreational sportspeople. The BPTB group, in fact, comprised more young persons and more males (Table 1). Only two subjects in this group (recreational, but competitive football players) were over 40, whereas in the ST–GR group six were under 30.

These were three patients not engaged in contact sports (cycling, swimming) and three selected for BPTB reconstruction, but modified intraoperatively due to the discovery of third-degree patellar chondropathy (one was a female professional volleyball player).

The concomitant lesions treated surgically are set out in Table 2. All subjects came in for a clinical stability after 1, 3, 6, 12 and 24 months and a KT1000 side-to-side examination at maximum manual force [7] after 6, 12 and 24 months (by which time a patient should have already resumed every type of activity). ROM was measured with a goniometer.

Table 2 Associated treated lesions
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One BPTB patient was not examined after 2 years because his ACL graft had a tear for a new trauma during a game of basketball at 15 months. He was therefore reoperated with ST–GR and not included in the 2-year follow-up group. Side-to-side KT1000 was used for objective evaluation of the anterior stability of the operated knee. Statistics were obtained with the analysis of variance and the Wilcoxon paired rank test.

Results

After 1 year, all patients had resumed sport at the same level as before the trauma and were satisfied with their results. ROM had been completely recovered, except by one BPTB subject with a 3° limitation of extension; this was subsequently treated by arthroscopic cleaning of a “cyclops syndrome” (due to a graft hypertrophy) [12].

The KT1000 side-to-side results after 1 and 2 years are illustrated in Tables 3, 4; Figs. 1, 2, 3, and 4. Clinical evaluation of stability (Lachman and Jerk tests) is illustrated in Table 5.

Table 3 KT1000 results in the two groups (in millimetres)
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Table 4 Detailed KT1000 results in the two groups at 1 and 2 years
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Fig. 1
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Graphic of the KT1000 results in the BPTB group

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Fig. 2
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Graphic of the KT1000 results in the ST–GR group

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Fig. 3
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Graphic of the KT1000 results in the compared two groups at 1 year

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Fig. 4
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Graphic of the KT1000 results in the compared two groups at 2 year

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Table 5 Clinical test results in the two groups at 1 and 2 years
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There were no between-group differences in concomitant disorders. Anterior knee pain was sporadic in both groups. It was always intermittent only and mostly in relation to the lower muscle tone with respect to the type of graft employed [3, 4, 11, 19, 21].

The KT1000 statistics in the BPTB group for the first year (mean 0.80) and the second year (mean 0.96) were not significantly different, and the same was true for the ST–GR group (1.18 and 1.20, respectively) (Figs. 3, 4). There were also no statistical differences between the results for the two groups, though the absolute values were slightly higher in the BPTB group (Tables 3, 4) (Figs. 1, 2, 3, 4).

Two patients, one in each group, had a constrained knee (-3 mm at the KT1000 side-to-side evaluation) without any symptom (Figs. 1, 2).

Discussion

As stated earlier, this study was designed to show whether the results of ACL reconstruction with different types of graft in two dissimilar groups of patients were comparable in terms of stability. In effect, the results were similar, though there was a slight, nonsignificant shift in stability in favour of the BPTB method. The KT1000 mean values at 1 and 2 years, in fact, were 0.80 and 0.96 for the BPTB group versus 1.18 and 1.20 for the ST–GR group, respectively. Subjects with a 3–4 mm side-to-side difference were 5% in the BPTB group versus 12% in the ST–GR group.

Generally speaking, therefore, our results were excellent in terms of stability and recovery of knee function. Stress may also be laid on the fact that a different choice of graft in two groups dissimilar in age and sex nonetheless led to superposable results.

Selection of the ST–GR method with its lower postopeartive morbidity proved well indicated for noncompetitive sportspeople and recreational sportswomen. Selection of the BPTB method, undoubtedly “more weighty” in terms of rehabilitation, produced slightly better results in terms of stability, taking into account also the fact that it benefited sportspersons at a greater competitive risk.

Our indications, not supported in the past by objective results such as those provided by the KT1000, have proved indisputably appropriate to the type of patient we have to treat. Provision via the same surgical technique of a type of treatment differed for every patient; “à la carte” as this is usually described, turned out to be suitable for the needs of both the patient and the surgeon.