Bellas Nicholas, Nayak Raghunandan, Pasha Mehreen, Wolf Megan, McDonald Thomas, Obopilwe Elifho, Geaney Lauren E
The University of Connecticut, Department of Orthopedics, Farmington, CT, USA.
The Bone & Joint Institute at Hartford Hospital, Department of Orthopedics, Hartford, CT, USA.
Foot Ankle Int. 2024 Dec;45(12):1406-1413. doi: 10.1177/10711007241281737. Epub 2024 Oct 13.
Insertional Achilles tendinopathy (IAT) is a common source of heel pain in active adults and athletes. The Zadek osteotomy (ZO) is a calcaneal dorsal closing wedge osteotomy that has demonstrated clinical success as a treatment for IAT, purported to favorably improve tendon mechanics, decrease impingement, and decrease pressure within the retrocalcaneal bursa. The present study aims to evaluate the biomechanical effects of ZO on Achilles strain, position of the Haglund prominence relative to the Achilles insertion, and retrocalcaneal pressure.
The ZO was performed on 10 fresh-frozen foot and ankle mid tibia-fibula cadaveric specimens. An osteotomy was performed using a 1-cm dorsal closing wedge procedure secured with a 7.0 mm cannulated screw. Point pressure sensor catheters and differential variable reluctance transducers were used to measure the retrocalcaneal pressure and Achilles strain, respectively, pre- and postosteotomy. Paired t-tests were utilized to detect statistical differences ( < .05).
After the ZO, the Haglund prominence was translated 9.9 mm anteriorly with respect to the insertion of the Achilles ( < .05) and the Achilles tendon insertion was translated 3.4 mm proximally ( < .05). The ratio of calcaneal length to greater tuberosity length, the X/Y ratio, increased from 2.56 to 3.52 with the osteotomy ( < .05). At maximum dorsiflexion, retrocalcaneal pressure decreased from 117 to 66 mm Hg (44%, = .018). The Achilles strain changed from 0.00362 to 0.00436 in the anterior fibers ( = .484) and changed from 0.00467 to 0.00283 in the posterior fibers ( = .088).
Biomechanical testing in a cadaveric model demonstrates that the ZO decreased retrocalcaneal pressure, shifted the Achilles tendon insertion proximally, increased the X/Y ratio of the calcaneus, and did not significantly change the strain of the Achilles tendon.
Despite the clinical success demonstrated in recent literature, there are no biomechanical studies describing the effect of the ZO on the biomechanics of the hindfoot, and the mechanism of symptom relief of the ZO for IAT is not well understood. The present study measures two potential ZO effects relative to Haglund prominence by measuring retrocalcaneal pressure and displacement of the Achilles tendon with respect to the Haglund prominence, and measures one ZO effect relative to calcification of the tendon by measuring the Achilles tendon strain.
插入性跟腱病（IAT）是活跃成年人和运动员足跟痛的常见原因。Zadek截骨术（ZO）是一种跟骨背侧闭合楔形截骨术，已证明作为IAT的治疗方法在临床上取得成功，据称可有效改善肌腱力学、减少撞击并降低跟腱后滑囊内的压力。本研究旨在评估ZO对跟腱应变、Haglund隆突相对于跟腱附着点的位置以及跟腱后压力的生物力学影响。
对10个新鲜冷冻的足踝中胫腓骨尸体标本进行ZO手术。采用1厘米背侧闭合楔形截骨术，并使用7.0毫米空心螺钉固定。分别在截骨术前和术后使用点压力传感器导管和差动可变磁阻传感器测量跟腱后压力和跟腱应变。采用配对t检验检测统计学差异（<0.05）。
ZO术后，Haglund隆突相对于跟腱附着点向前移位9.9毫米（<0.05），跟腱附着点向近端移位3.4毫米（<0.05）。跟骨长度与大结节长度之比（X/Y比）从2.56增加到3.52（<0.05）。在最大背屈时，跟腱后压力从117毫米汞柱降至66毫米汞柱（44%，P = 0.018）。跟腱前纤维应变从0.00362变为0.00436（P = 0.484），后纤维应变从0.00467变为0.00283（P = 0.088）。
尸体模型中的生物力学测试表明，ZO降低了跟腱后压力，使跟腱附着点向近端移位，增加了跟骨的X/Y比，且未显著改变跟腱应变。
尽管近期文献显示了临床成功，但尚无生物力学研究描述ZO对后足生物力学的影响，且ZO治疗IAT的症状缓解机制尚不清楚。本研究通过测量跟腱后压力和跟腱相对于Haglund隆突的位移来测量ZO相对于Haglund隆突的两种潜在影响，并通过测量跟腱应变来测量ZO相对于肌腱钙化的一种影响。
