절단된 토끼 아킬레스 힘줄의 시간 경과에 따른 수술 및 비수술 치료후 생역학적 특성 및 형태 비교

Abstract

[한글]

아킬레스힘줄 파열의 치료는 수술 방법과 비수술 방법이 논란되고 있다. 1920년대부터 1960년대까지는 수술 치료가 주된 치료방법이었지만, 여러 동물실험 및 임상 관찰에서 아킬레스힘줄의 자연 치유능력이 보고된 후, 1970년대부터 비수술 치료로도 만족스러운 결과를 얻을 수 있으므로 여러가지 합병증이 생기는 수술 치료가 필요 없다는 주장이 나오기 시작하였다. 그러나 수술을 선호하는 사람은 비수술 치료의 높은 재파열율을 단점으로 지적하고 있다. 아킬레스힘줄 파열 환자 중 약 25%는 초진시 정확히 진단되지 못하므로 치료가 지연되는 경우가 적지 않고, 이런 경우 보존적인 치료방법을 선택할 수 있을 것인지, 또한 재파열율은 높지 않을 것인지에 대해서 의구심을 가지고 있다. 그러므로 이 연구에서는 토끼 아킬레스힘줄을 절단한 후 시차를 두고 수술과 비수술로 치료하여 생역학적 특성과 형태를 비교하고자 하였다. 실험동물은 성숙 토끼 72마리를 사용하였으며, 아킬레스힘줄을 절단 후 치료시기와 방법에 따라 즉시 수술, 즉시 비수술, 1주일 지연수술, 1주일 지연 비수술, 2주일 지연 수술, 2주일 지연 비수술소군으로 구분하였다. 치료 후

4주일간 석고붕대 고정을 하고 각 소군에서 10마리씩 희생하여 육안, 생역학적 및 조직학적 검사를 시행하고, 각 소군마다 2마리씩 Microfil관류 검사를 시행하여 다음의 결과를 얻었다.

1, 육안 검사상 치유조직의 길이는 즉시 수술소군에서 가장 짧았고 2주일 지연 비수술소군에서 가장 길었다. 동일한 치료시기에는 모든 수술소군이 비수술소군보다, 또한 동일 치료방법의 경우 조기치료가 지연치료보다 치유조직의 길이가 짧았다.

2. 생역학적 검사상 최대하중은 동일한 방법으로 치료한 경우에는 치료가 지연될수록 낮아졌고, 즉시 수술소군과 2주일 지연 수술소군, 1주일 지연 수술소군과 2주일 지연 수술소군, 그리고 즉시 비수술소군과 2주일 지연 비수술소군간에 통계적으로 유의한 차이가

있었다. 동일한 치료시기의 최대하중은 수술소군과 비수술소군간에 통계적으로 유의한 차이가 없었다. 흡수에너지와 강성도 최대하중과 비슷한 결과를 볼 수 있었다.

3. 조직학적 검사상 치유조직의 성숙정도는 평균적으로 2주일 지연 수술소군에서 가장 낮았고,1주일 지연 수술소군, 즉시 수술소군, 모든 비수술소군 순으로 낮았다.

4. Microfil 관류를 이용한 미세혈관 검사상 모든 실험소군의 치유조직에서는 신생혈관의 배열이 불규칙하고 굵기 차이가 심하며 서로 많은 부위에서 연결되어 그물같은 구조를 보였다. 혈관의 불규칙한 모양, 배열 및 주행은 즉시 수술과 비수술소군보다 지연 수술소군에서 더 심한 경향을 보였다.

이상의 결과로 미루어 아킬레스힘줄 파열시 치료방법에 상관없이 조기에, 늦어도 1주일 이내에 치료를 시작하여야 우수한 힘줄의 인장 강도를 얻을 수 있고, 재파열의 관점에서 보면 치료가 2주일 이내에 이루어진다면 비수술 치료와 수술 치료가 비슷한 결과를 가져 올 수 있을 것으로 생각된다.

A comparison of biomechanical and morphological characteristics between operative

and nonoperative treatments of tenotomized rabbit Achilles tendon over lapse of

tome

Sung Soo Kim

Department of Medical Science The Graduate School, Yonsei University

(Directed by Professor Nam Hyun Kim)

The argument about the operative versus conservative cast treatment of Achilles

tendon rupture still remains unsolved. Operative treatment prevailed between the

1920s and 1960s. Since the 1970s, based on the reports of natural repair in the

Achilles tendon of both animals and man, many have suggested that nonoperative

treatment rather than surgical repair might be employed because of good results

without any complications. However some opponents argue the high rate of rerupture

of Achilles tendon treated by the cast. It has been reported that ruptures of

Achilles tendon went unnoticed at the first examination in about one fourth of

cases. In those delayed cases, the surgeon is faced with the dilemma whether

nonoperative treatment is guaranteed or not on the suspicion of the high rerupture

rate. This study was attempted to compare the biomechanical and morphological

results between operative and nonoperative treatments of experimentally tenotomized

rabbit Achilles tendon over lapse of time.

A total of 72 adult rabbits were used. After tenotomizing the Achilles tendons,

the subiects were divided into three groups according to the time of the initiation

of treatment and each group was subdivided into two further subgroups according to

the method of treatment; immediate operation and nonoperation, 1 week delayed

operation and nonoperation, and 2 weeks delayed operation and nonoperation

subgroups.

Ten animals from each subgroup were sacrificed after four weeks of cast

immobilization and the Achilles tendons were prepared for the gross, biomechanical

and histological examinations. At the same time, two animals from each subgroup

were examined by Microfil perfusion for microvascular changes in the healed

tendons. The following results were obtained.

1. On Bross examination, the length of healed tissue was the shortest in the

immediate operation subgroup and the longest in the 2 weeks delayed nonoperation

subgroup. In each group, the lengths of healed tissues of all operative subgroups

were shorter than those of the nonoperative subgroups, and in each treatment

method, the earlier the treatment was started, the shorter the length.

2. On biomechanical examination, maximal loads were decreased with the lapse of

time in each treatment method, and there were statistical significances between the

immediate and 2 weeks delayed operation subgroups, 1 week and 2 weeks delayed

operation subgroups, and immediate and 2 weeks delayed nonoperation subgroups.

Maximal loads were higher in the operative subgroups of each group but there were

no statistical significances between operative and nonoperative treatments in each

group. The results of absorption energy and stiffness were similar to those of

maximal load.

3. On histologic examination, the maturation degree of healed tissue was the

lowest in the 2 weeks delayed operation subgroup and followed by the 1 week delayed

operation subgroup, immediate operation subgroup, and three nonoperation subgroups.

4. Microfil perfusion study revealed irregular and tortuous microvessels in all

six subgroups compared to those of normal control, and these changes were more

remarkable in the delayed operation subgroups.

In conclusion, these results suggest that a rupture of the Achilles tendon should

be treated as early as possible, preferably within 1 week, in order to achieve a

high tensile strength irrespective of the treatment method. In terms of rerupture,

nonoperative treatment is comparable with surgical treatment if a rupture of

Achilles tendon is managed within 2 weeks of injury.

[영문]

The argument about the operative versus conservative cast treatment of Achilles tendon rupture still remains unsolved. Operative treatment prevailed between the 1920s and 1960s. Since the 1970s, based on the reports of natural repair in the Achilles tendon of both animals and man, many have suggested that nonoperative treatment rather than surgical repair might be employed because of good results without any complications. However some opponents argue the high rate of rerupture

of Achilles tendon treated by the cast. It has been reported that ruptures of Achilles tendon went unnoticed at the first examination in about one fourth of cases. In those delayed cases, the surgeon is faced with the dilemma whether nonoperative treatment is guaranteed or not on the suspicion of the high rerupture rate. This study was attempted to compare the biomechanical and morphological results between operative and nonoperative treatments of experimentally tenotomized rabbit Achilles tendon over lapse of time.

A total of 72 adult rabbits were used. After tenotomizing the Achilles tendons, the subiects were divided into three groups according to the time of the initiation of treatment and each group was subdivided into two further subgroups according to

the method of treatment; immediate operation and nonoperation, 1 week delayed operation and nonoperation, and 2 weeks delayed operation and nonoperation subgroups.

Ten animals from each subgroup were sacrificed after four weeks of cast immobilization and the Achilles tendons were prepared for the gross, biomechanical and histological examinations. At the same time, two animals from each subgroup were examined by Microfil perfusion for microvascular changes in the healed

tendons. The following results were obtained.

1. On Bross examination, the length of healed tissue was the shortest in the immediate operation subgroup and the longest in the 2 weeks delayed nonoperation subgroup. In each group, the lengths of healed tissues of all operative subgroups were shorter than those of the nonoperative subgroups, and in each treatment

method, the earlier the treatment was started, the shorter the length.

2. On biomechanical examination, maximal loads were decreased with the lapse of time in each treatment method, and there were statistical significances between the immediate and 2 weeks delayed operation subgroups, 1 week and 2 weeks delayed

operation subgroups, and immediate and 2 weeks delayed nonoperation subgroups.

Maximal loads were higher in the operative subgroups of each group but there were no statistical significances between operative and nonoperative treatments in each group. The results of absorption energy and stiffness were similar to those of maximal load.

3. On histologic examination, the maturation degree of healed tissue was the lowest in the 2 weeks delayed operation subgroup and followed by the 1 week delayed operation subgroup, immediate operation subgroup, and three nonoperation subgroups.

4. Microfil perfusion study revealed irregular and tortuous microvessels in all six subgroups compared to those of normal control, and these changes were more remarkable in the delayed operation subgroups.

In conclusion, these results suggest that a rupture of the Achilles tendon should be treated as early as possible, preferably within 1 week, in order to achieve a high tensile strength irrespective of the treatment method. In terms of rerupture, nonoperative treatment is comparable with surgical treatment if a rupture of Achilles tendon is managed within 2 weeks of injury.