AOFAS 2012 ANNUAL SUMMER MEETING Subtalar Distraction Two Bone-Block Arthrodesis for Calcaneal Malunion
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Introduction Late complications of Intra-articular Calcaneal Fractures The goals of Subtalar Distraction Arthrodesis Subtalar incongruity and arthritis Loss of calcaneal height Lateral wall expansion Anterior tibiotalar impingement Varus or valgus malalignment of the hindfoot Weakened Achilles lever arm Restoration of heel height Decompression of the anterior ankle joint Elimination of subtalar arthrosis Correction of hindfoot malalignment Purpose : to evaluate the results of Subtalar Distraction Bone-block Arthrodesis using two bone-block for subtalar arthritis after calcaneus fractures
Materials From Jan. 2004 to Jan. 2011 19 feet of 15 patients All cases : Calcaneal Malunion (Stephens and Sanders type 2) after Intra-articular Calcaneus Fractures Male / Female : 14 / 1 Age : average 43.3 Y. (28 ~ 64 Y.) Follow-up : average 37.8 M. (9 ~ 77 M.) Interval between initial injury and definite op. (STDA) : average 19.6 M. (5 ~ 45 M.) - except 1 case (30 years) Initial treatment of Calcaneal Fracture Conservative treatment with casting : 6 cases CR/IF with axial pinning : 7 cases OR/IF with plate & screw & bone graft : 6 cases
Methods Radiologic evaluation TCH : talo-calcaneal height (A) TCA : talo-calcaneal angle (B) TDA : talar declination angle (C) TFMA : talo-first metatarsal angle (D) Operative Techniques Lateral Extensile Approach Subtalar Joint Preperation - Medial release Joint Distraction - lamina spreader or distractor Bone-Block Harvest - 2 bone-block from ASIS Fixation - 2 Screws fixation Redrawn from Chen et al. : J Trauma Injury Infection & Critical care. 45(4):731, 1998.
Results Union : 18 / 19 cases average 5 months Complications Non-union Varus deformity : 1 case (Revision Op. at POD 1yr Union) AOFAS Ankle-Hindfoot Scale : 51.6 80.3 point Persistent pain : 3 cases (but, improved than preoperative state) (Pain : 17.9 33.3 point) Meralgia paresthetica :1 case
Results Preop. Postop. Last F/U TCH (mm) 68.3 74.2 72.9 4.6 TCA( o ) 20.3 26.2 22.7 2.4 TDA( o ) 13.1 20.6 17.4 4.3 TFMA ( o ) 8.1 3.3 5.3 2.8 76 73 70 67 64 Preop. Postop. Last F/U 30 25 20 15 TCH TCA TDA TFMA 10 Preop. Postop. Last F/U 22 20 18 16 14 12 10 Preop. Postop. Last F/U 12 11 10 9 8 7 6 Preop. Postop. Last F/U TCH : talo-calcaneal height TCA : talo-calcaneal angle TDA : talar declination angle TFMA : talo-first metatarsal angle
Discussion Indications for STDA Myerson et al. (JBJS Am. 1993) - Talo-calcaneal height loss > 8mm - Anterior tibio-talar impingement Marti et al. (JBJS Br. 1999) - Persistent pain due to incongruent subtalar joint - Hindfoot deformity (valgus/varus) Two Bone-Block To match Bone-block to Articular width - increasing Stability of Fusion site To correct Varus deformity Height loss during follow-up period Myerson et al. (JBJS Am. 1993) - due to absorption of the bone block Our study : 1.3 mm Chan et al. (J tauma 1998) - one bone-block height loss : 4.7 mm - two bone-blocks height loss : 1.4 mm
Conclusion Our Indications of STDA - Talo-calcaneal height loss > 8mm - anterior tibio-talar impingement with anterior ankle pain Promising procedure for complicated subtalar arthritis after calcaneal fractures. Subtalar distraction arthrodesis using tricortical double bone block However, longer follow-up will be needed.
Reference Carr JB, Hansen ST, Benirschke SK: Subtalar distraction bone block fusion for late complication of os calcis fractures. Foot Ankle Int, 9: 81-86, 1988. Chen YJ, Huang TJ, Hsu KY, Hsu RW, Chen CW: Subtalar distractional realignment arthrodesis with wedge bone grafting and lateral decompression for calcaneal malunion. J Trauma, 45: 729-737, 1998. Marti RK, de Heus JA, Roolker W, Poolman RW, Bessalaar PP: Subtalar arthrodesis with correction of deformity after fractures of the os calcis. J Bone Joint Surg, 81-B: 611-616, 1999. Myerson M, Quill GE Jr: Late complications of fractures of the calcaneus. J Bone Joint Surg, 75-A: 331-341, 1993. Pollard JD, Schuberth JM: Posterior bone block distraction arthrodesis of the subtalar joint: a review of 22 cases. J Foot Ankle Surg, 47: 191-198, 2008. Romash MM: Reconstructive osteotomy of the calcaneus with subtalar arthrodesis for malunited calcaneal fractures. Clin Orthop Relat Res, 290: 157-167, 1993.