前十字靭帯急性損傷に対しては早期手術の成績が良好

前十字靭帯 (ACL)損傷は最も一般的なスポーツ外傷の一つで、その頻度は49ー75/100,000人・年とされています。過去には外科的治療と非手術療法を比較した臨床試験（KANON trial）が行われ、運動療法と組み合わせた保存的治療が良好な成績を示すことが示されています(Frobell et al., N Engl J Med 2010;363:331-42; Frobell et al., BMJ 2013;346:f232)。しかしこの結果出てからもACL損傷に対する手術は年々増加しています。これはKANON trialでは少なくとも半数の患者で再建術が不要であったためではないかと考えられています。今回のConservative versus Operative Methods for Patients with ACL Rupture Evaluation (COMPARE) trialでは、ACLの急性損傷に対して早期手術とリハビリテーション後に希望者に待機手術を行った場合との成績を比較しました。

受傷後2カ月以内のACL損傷患者 (18ー65歳)を早期（6週間以内）に再建術を行うEarly reconstruction (E)群、最低3カ月間のリハビリテーション後に不安定性が残存している、あるいは活動レベルに不満がある場合に再建術を行うRehabilitation with optional delayed reconstruction (R)群に振り分けて比較しました。研究に参加した患者は167人で、85人がE群、82人がR群に振り分けられました。E群のうち3名は再建術を受けませんでした（理由は手術に対する恐怖や手術時のpivot shift陰性）。78人はhamstring graft、4人は膝蓋腱 (BTB)を用いて再建されました。R群のうち41人が平均ランダム化後10.6ヵ月で再建術を受けました (38人がhamstring、3人がBTB)。手術は全て関節鏡視下で行われました。

Primary outcomeである術後24ヵ月以降のInternational Knee Documentation Committee scoreを用いた患者の自覚症状、膝機能、スポーツ参加の比較では、E群の方が有意に良好でした（群間差は5.3, 95% confidence interval 0.6 to 9.9）。3カ月後にはR群の方が良好な成績でしたが、点数は９ヵ月後に逆転しました。群間の差は12ヵ月後には小さくなりましたが、その後24ヵ月までE群が良好でした。Secondary outcomeである2年後のKnee Injury and Osteoarthritis Outcome sport score (P=0.039)、quality of life score (P=0.002)いずれもE群で有意に良好な成績を示しました。Lysholm scoreは6, 9, 12, 24ヵ月のfollow-upでいずれもE群で有意に良好でした。安静時および活動時の疼痛に群間差はありませんでした。半月板の処置が必要だったのはE群のうち24例、R群の17例でした。重篤な有害事象としては逆側のACL損傷 (E群で3例、R群で1例)、ACL再断裂 (E群4例、R群2例)。Post hoc analysisでは2年のfollow-up後にgiving wayを訴えた患者はR群で高頻度でした（E群2.5%, R群15.0%）。この研究結果は、ACL急性損傷患者に対しては早期の再建術が良好な成績を示すことを示唆していますが、R群との差は大きなものではなく、臨床的な意義を持つかについては議論の余地があるかもしれません。

Reijman et al., Early surgical reconstruction versus rehabilitation with elective delayed reconstruction for patients with anterior cruciate ligament rupture: COMPARE randomised controlled trial.

BMJ 2021;372:n375

Early surgical reconstruction versus rehabilitation with elective delayed reconstruction for patients with anterior cruciate ligament rupture: COMPARE randomised controlled trial

Objective To assess whether a clinically relevant difference exists in patients’ perceptions of symptoms, knee function, and ability to participate in sports over a period of two years after rupture of the anterior cruciate ligament (ACL) between two commonly used treatment regimens. Design Open labelled, multicentre, parallel randomised controlled trial (COMPARE). Setting Six hospitals in the Netherlands, between May 2011 and April 2016. Participants Patients aged 18 to 65 with an acute rupture of the ACL, recruited from six hospitals. Patients were evaluated at three, six, nine, 12, and 24 months. Interventions 85 patients were randomised to early ACL reconstruction and 82 to rehabilitation followed by optional delayed ACL reconstruction after a three month period (primary non-operative treatment). Main outcomes Patients’ perceptions of symptoms, knee function, and ability to participate in sporting activities were assessed with the International Knee Documentation Committee score (optimum score 100) at each time point over 24 months. Results Between May 2011 and April 2016, 167 patients were enrolled in the study and randomised to one of two treatments (mean age 31.3; 67 (40.%) women), and 163 (98%) completed the trial. In the rehabilitation and optional delayed ACL reconstruction group, 41 (50%) patients underwent reconstruction during follow-up. After 24 months, the early ACL reconstruction group had a significantly better (P=0.026) but not clinically relevant International Knee Documentation Committee score (84.7 v 79.4 (difference between groups 5.3, 95% confidence interval 0.6 to 9.9). After three months of follow-up, the International Knee Documentation Committee score was significantly better (P=0.002) for the rehabilitation and optional delayed ACL reconstruction group (difference between groups −9.3, −14.6 to −4.0). After nine months of follow-up, the difference in the International Knee Documentation Committee score changed in favour of the early ACL reconstruction group. After 12 months, differences between the groups were smaller. In the early ACL reconstruction group, four re-ruptures and three ruptures of the contralateral ACL occurred during follow-up versus two re-ruptures and one rupture of the contralateral ACL in the rehabilitation and optional delayed ACL reconstruction group. Conclusions In patients with acute rupture of the ACL, those who underwent early surgical reconstruction, compared with rehabilitation followed by elective surgical reconstruction, had improved perceptions of symptoms, knee function, and ability to participate in sports at the two year follow-up. This finding was significant (P=0.026) but the clinical importance is unclear. Interpretation of the results of the study should consider that 50% of the patients randomised to the rehabilitation group did not need surgical reconstruction. Trial registration Netherlands Trial Register NL 2618.

Early surgical reconstruction versus rehabilitation with elective delayed reconstruction for patients with anterior cruciate ligament rupture: COMPARE randomised controlled trial