Immediate weight bearing with early mobilization of the ankle after surgical repair of the acutely ruptured Achilles tendon has now become standard protocol around the world. (1-7) More recently, a compelling body of evidence has validated equivalent outcomes with non-operative treatment of the acute Achilles tendon rupture compared to immediate surgical repair. ( 8-9) In the non-operative treatment of the acute Achilles rupture, immediate weight bearing with early immobilization has again produced the best results. (3,10)
Studies of early weight bearing after Achilles rupture have utilized various types of walking boots and casts to limit ankle joint motion and protect the injured tendon. There is no clear preference or standard for which type of immobilizing device or which position of ankle joint alignment is favored. (11) While standard practice has favored positioning the ankle in extreme equinus when weight bearing after an Achilles rupture, studies have shown favorable outcome when orthoses or braces are used which simply restrict ankle dorsiflexion to neutral (90 degrees).
Positioning the ankle in extreme ( 30 degrees) plantarflexion puts the Achilles in a slack position without the benefits of loading which is essential to proper tendon healing. Furthermore, decreased muscular activity in the calf while non-weight bearing in this position may account for long term deficits which patients suffer after Achilles tendon rupture including reduced calf circumference and reduced calf muscle strength. (6)
These studies have shown that there are no increased risks of re-rupture with weight bearing in an AFO regardless of whether the ankle was maintained in a plantarflexed position or allowed dorsiflexion to neutral. ( 12,13,14)
While intuitively we assume that less tension is placed on the Achilles when the ankle is held plantarflexed in a boot or AFO, we do not consider the compensatory muscle activity and tension which develops in the Achilles when the patient is required to walk in an extreme plantarflexed position at the ankle joint. A study of Achilles tension in human subjects showed that INCREASED tension in the Achilles resulted when the foot was positioned 20 degrees plantarflexed in a brace compared to a neutral ankle position. (15) Thus, a CAM type walking boot with the ankle set plantarflexed 20 degrees, causes the patient to walk on the forefoot only, which greatly increases Achilles tension to the same level as when they walked barefoot. (15) On the other hand, when patients ambulate in a walking boot, set at 90 degrees, two studies have shown that the reduction in contractile activity in the gastrocnemius and soleus is reduced to only 79% of normal walking ( 21% overall reduction). (16,17) However, when a 1 inch heel lift is applied inside the boot, reduces contractile activity to 57% of normal walking, while causing minimal plantarflexion of the ankle to 10 degrees. (16) Therefore, a 1 inch heel lift to a walking boot can be expected to reduce muscular activity of the ankle plantarflexors by 22% compared to walking in a boot in neutral position.
Walking boots with heel lifts will increase heel pressures while causing gait disturbances. (18) These negative changes include decreased time spent in terminal stance (propulsion) and pre-swing phase. (18) This accounts for the development of pain in the hips and knees reported by patients who must be immobilized in walking boots. A carbon fiber AFO with a one-inch heel raise will protect the Achilles by limiting ankle dorsiflexion, while restoring near-normal gait paramenters compared to a walking boot. The authors stated that this carbon fiber AFO could lead to an accelerated return to function and avoid the effects of disuse atrophy in the calf musculature. (18)
- Thevendran G, Sarraf KM, Patel NK, Sadri A, Rosenfeld P. The ruptured Achilles tendon: a current overview from biology of rupture to treatment. Musculos- kelet Surg 2013;97(1):9
- OlssonN,SilbernagelKG,ErikssonBI,SansoneM,BrorssonA,Nilsson-Helander K, et al. Stable surgical repair with accelerated rehabilitation versus nonsurgical treatment for acute Achilles tendon ruptures: a randomized controlled study. Am J Sports Med 2013;41(12):2867–76.
- Kearney RS, Costa ML. Current concepts in the rehabilitation of an acute rupture of the tendo Achillis. J Bone Joint Surg Br 2012;94(1):28–31.
- Chiodo CP, Glazebrook M, Bluman EM, Cohen BE, Femino JE, Giza E, et al. American Academy of Orthopaedic Surgeons clinical practice guideline on treatment of Achilles tendon rupture. J Bone Joint Surg Am 2010;92(14):2466–8.
- Huang J, Wang C, Ma X, Wang X, Zhang C, Chen L. Rehabilitation regimen after surgical treatment of acute achilles tendon ruptures: a systematic review with meta-analysis. Am J Sports Med 2014. http://dx.doi.org/10.1177/ 0363546514531014.
- Kearney RS, McGuinness KR, Achten J, Costa ML. A systematic review of early rehabilitation methods following a rupture of the Achilles tendon. Physiotherapy 2012;98(1):24–32.
- Maffulli N, Tallon C, Wong J, Lim KP, Bleakney R. Early weightbearing and ankle mobilization after open repair of acute midsubstance tears of the achilles tendon. Am J Sports Med 2003;31(5):692–700.
- Nilsson-Helander K, Silbernagel KG, Thomeé R, Faxén E, Olsson N, Eriksson BI, Karlsson J. Acute Achilles tendon rupture: a randomized, controlled study comparing surgical and nonsurgical treatments using validated outcome measures. Am J Sports Med. 2010;38:2186–93.
- Willits K, Amendola A, Bryant D, Mohtadi NG, Giffin JR, Fowler P, Kean CO, Kirkley A. Operative versus nonoperative treatment of acute Achilles tendon ruptures: a multicenter randomized trial using accelerated functional rehabilitation. J Bone Joint Surg Am. 2010;92:2767–75.
- Costa ML, MacMillan K, Halliday D, Chester R, Shepstone L, Robinson AH, et al. Randomised controlled trials of immediate weight-bearing mobilisation for rupture of the tendo Achillis. J Bone Joint Surg Br 2006;88(1):69–77.
- Kearney RS, Parsons N, Underwood M, Costa ML. Achilles tendon rupture rehabilitation: a mixed methods investigation of current practice among orthopaedic surgeons in the United Kingdom. Bone Joint Res. 2015 Apr;4(4):65-9.
- Kauranen K, Kangas J, Leppilahti J. Recovering motor performance of the foot after Achilles rupture repair: a randomized clinical study about early functional treatment vs. early immobilization of Achilles tendon in tension. Foot Ankle Int. 2002;23(7):600-605.
- Rantanen J, Hurme T, Paananen M. Immobilization in neutral versus equinus position after Achilles tendon repair: a review of 32 patients. Acta Orthop Scand. 1993;64(3):333-335.
- Speck M, Klaue K. Early full weightbearing and functional treatment after surgical repair of acute Achilles tendon rupture. Am J Sports Med. 1998;26(6):789-793.
- Froberg A, Komi PIshikawa MMovin T, Arndt A . Force in the achilles tendon during walking with ankle foot orthosis. Am J Sports Med.2009 Jun;37(6):1200-7
- Akizuki KH, Gartman EJ, Nisonson B, Ben-Avi S, McHugh MP. The relative stress on the Achilles tendon during ambulation in an ankle immobiliser: implications for rehabilitation after Achilles tendon repair. Br J Sports Med. 2001;35(5):329-333, discussion 333-334.
- Kadel NJ, Segal A, Orendurff M, Shofer J, Sangeorzan B. The efficacy of two methods of ankle immobilization in reducing gastrocnemius, soleus, and peroneal muscle activity during stance phase of gait. Foot Ankle Int. 2004;25(6):406-409.
- Kearney RS, Lamb SE, Achten J, Parsons NR, Costa ML. In-shoe plantar pres- sures within ankle-foot orthoses: implications for the management of achilles tendon ruptures. Am J Sports Med 2011;39:2679–2685.