Drijfhout van Hooff Cornelis Christiaan, Verhage Samuel Marinus, Hoogendoorn Jochem Maarten
Departement of General Surgery, Bronovo Hospital, The Hague, Netherlands
Departement of General Surgery, Medisch Centrum Haaglanden, The Hague, Netherlands.
Foot Ankle Int. 2015 Jun;36(6):673-8. doi: 10.1177/1071100715570895. Epub 2015 Feb 11.
One of the factors contributing to long-term outcome of posterior malleolar fractures is the development of osteoarthritis. Based on biomechanical, cadaveric, and small population studies, fixation of posterior malleolar fracture fragments (PMFFs) is usually performed when fragment size exceeds 25-33%. However, the influence of fragment size on long-term clinical and radiological outcome size remains unclear.
A retrospective cohort study of 131 patients treated for an isolated ankle fracture with involvement of the posterior malleolus was performed. Mean follow-up was 6.9 (range, 2.5-15.9) years. Patients were divided into groups depending on size of the fragment, small (<5%, n = 20), medium (5-25%, n = 86), or large (>25%, n = 25), and presence of step-off after operative treatment. We have compared functional outcome measures (AOFAS, AAOS), pain (VAS), and dorsiflexion restriction compared to the contralateral ankle and the incidence of osteoarthritis on X-ray.
There were no nonunions, 56% of patients had no radiographic osteoarthritis, VAS was 10 of 100, and median clinical score was 90 of 100. More osteoarthritis occurred in ankle fractures with medium and large PMFFs compared to small fragments (small 16%, medium 48%, large 54%; P = .006). Also when comparing small with medium-sized fragments (P = .02), larger fragment size did not lead to a significantly decreased function (median AOFAS 95 vs 88, P = .16). If the PMFF size was >5%, osteoarthritis occurred more frequently when there was a postoperative step-off ≥1 mm in the tibiotalar joint surface (41% vs 61%, P = .02) (whether the posterior fragment had been fixed or not). In this group, fixing the PMFF did not influence development of osteoarthritis. However, in 42% of the cases with fixation of the fragment a postoperative step-off remained (vs 45% in the group without fixation).
Osteoarthritis is 1 component of long-term outcome of malleolar fractures, and the results of this study demonstrate that there was more radiographic osteoarthritis in patients with medium and large posterior fragments than in those with small fragments. Radiographic osteoarthritis also occurred more frequently when postoperative step-off was 1 mm or more, whether the posterior fragment was fixed or not. However, clinical scores were not different for these groups.
Level IV, retrospective case series.
后踝骨折长期预后的影响因素之一是骨关节炎的发生。基于生物力学、尸体研究和小样本量研究，当后踝骨折块（PMFF）大小超过25%-33%时，通常会对其进行固定。然而，骨折块大小对长期临床和影像学预后的影响仍不明确。
对131例单纯踝关节骨折伴后踝骨折的患者进行回顾性队列研究。平均随访时间为6.9年（范围2.5-15.9年）。根据骨折块大小将患者分为三组，小骨折块组（<5%，n=20）、中骨折块组（5%-25%，n=86）、大骨折块组（>25%，n=25），并观察手术治疗后是否存在台阶样改变。比较了功能预后指标（美国足踝外科协会评分、美国矫形外科医师学会评分）、疼痛（视觉模拟评分）、与对侧踝关节相比的背屈受限情况以及X线片上骨关节炎的发生率。
无骨不连发生，56%的患者无影像学骨关节炎表现，视觉模拟评分为100分中的10分，临床评分中位数为100分中的90分。与小骨折块组相比，中、大骨折块组的踝关节骨折患者发生骨关节炎的情况更多（小骨折块组16%，中骨折块组48%，大骨折块组54%；P=0.006）。此外，比较小骨折块组和中骨折块组时（P=0.02），较大的骨折块大小并未导致功能显著下降（美国足踝外科协会评分中位数95分对88分，P=0.16）。如果PMFF大小>5%，当胫距关节面术后台阶样改变≥1mm时，骨关节炎更易发生（41%对61%，P=0.02）（无论后踝骨折块是否固定）。在该组中，固定PMFF对骨关节炎的发生没有影响。然而，在42%的骨折块固定病例中仍存在术后台阶样改变（未固定组为45%）。
骨关节炎是踝关节骨折长期预后的一个因素，本研究结果表明，中、大后踝骨折块患者的影像学骨关节炎比小骨折块患者更多。无论后踝骨折块是否固定，当术后台阶样改变为1mm或更大时，影像学骨关节炎也更易发生。然而，这些组的临床评分并无差异。
IV级，回顾性病例系列研究。
