Achilles Rupture, Surgery or Functional Rehab
The old rule that a torn Achilles always goes to the OR was built on trials that immobilized the nonoperative group in a rigid cast, but modern rehab has closed most of the gap.
Takeaways
- Achilles rupture is rising in incidence and concentrates in sport-active men in their 30s and 40s. A 2026 meta-analysis of more than 630 million people found pooled incidence of 15.7 per 100,000 person-years, rising 2.7% a year, with a male-to-female ratio of 3.18 and peak incidence in men aged 30-49 at 42.6 per 100,000 person-years. About 68% of ruptures were sport related. (Kotsifaki et al, Sports Med 2026;56:1467-1487, PMID 41933260).
- The calf squeeze test outperforms every other single exam sign for a complete rupture. Pooled across 3 studies, the calf squeeze (Thompson) test reached sensitivity as high as 0.96 and specificity as high as 0.93, the best of any clinical measure tested, with a negative likelihood ratio as low as 0.04. (Reiman et al, J Athl Train 2014;49:820-829, PMID 25243736).
- A complete exam triad is enough to diagnose rupture, MRI is not required. Patients diagnosed on an abnormal Thompson test, loss of resting tension and a palpable gap reached 100% sensitivity against intraoperative findings, while adding MRI delayed surgery by roughly 7 days (12.4 versus 5.6 days to surgery). Reserve imaging for an equivocal exam or a delayed presentation. (Garras et al, Clin Orthop Relat Res 2012;470:2268-2273, PMID 22538958).
- The tendon ruptures most often in its own watershed zone, and the sural nerve is the structure at risk when it is repaired. The hypovascular watershed zone sits roughly 2-6 cm proximal to the calcaneal insertion, and percutaneous repair studies have found the sural nerve entrapped in the suture, making its posterolateral course the structure a resident checks for. (Lagergren & Lindholm, Acta Chir Scand 1959;116:491-495, PMID 13660718; Zappia et al, Foot Ankle Surg 2017;24:342-346, PMID 29409243).
- Functional rehab, not the choice of surgery, is what closes the rerupture gap. Pooling 10 randomized trials, rerupture rates were statistically equal between operative and nonoperative treatment when both used early range of motion rehab (risk difference 1.7%, p=0.45), but surgery cut rerupture risk by 8.8% (p=0.001) when nonoperative care meant rigid immobilization instead. Surgery still had a 15.8% higher complication rate. (Soroceanu et al, J Bone Joint Surg Am 2012;94:2136-2143, PMID 23224384).
- The old teaching that surgery halves rerupture risk came from trials that immobilized the nonoperative arm in a rigid cast. A 1993 randomized trial reported rerupture in 3 of 56 operative patients against 7 of 55 treated in a cast, and a 1981 randomized trial reported 2 reruptures after surgery against 5 after nonoperative cast treatment. Neither trial used early motion rehab. (Cetti et al, Am J Sports Med 1993;21:791-799, PMID 8291628; Nistor, J Bone Joint Surg Am 1981;63:394-399, PMID 7204438).
- Surgeons changed practice once the trial evidence changed. In a population-based Ontario cohort of 27,607 patients, the rate of surgical repair fell from 20.1 to 9.2 per 100 ruptures between 2003 and 2013, with the sharpest drop after 2009, tracking the publication of the randomized trials showing equal rerupture with functional rehab. (Sheth et al, Bone Joint J 2017;99-B:78-86, PMID 28053261).
- Functional rehab means early weight bearing in a hinged brace, not a rigid cast, and strength deficits can persist either way. The UKSTAR brace arm bore weight immediately while the brace was adjusted toward neutral over 8 weeks, and rerupture did not differ from a rigid cast (6% versus 5%, p=0.40). Calf strength and thickness can stay below the uninjured side 2 years later regardless of rehab path. (Costa et al, Lancet 2020;395:441-448, PMID 32035553; Geremia et al, J Appl Physiol 2026;140:1789-1801, PMID 42133049).