Aust. N . Z . J. Surg.
965
1992,62,965-968
SURGICAL TECHNIQUE A NEW TECHNIQUE OF ANKLE ARTHRODESIS D. H. SONNABEND AND D. DUCKWORTH Department of Orthopaedic und Truumatic Surgery, The Royal North Shore Hospital of Sydney, New South Wales, Austruliu A new technique of ankle arthrodesis is described and the results of 12 consecutive procedures are assessed. The method described employs three cannulated transfixion screws and an anterior approach to the ankle. Eleven of the 12 ankles proceeded to solid fusion. One patient developed a painless fibrous non-union. There were no other significant complications. This simple technique provides good compression and adequate resistance to rotatory and angulatory stresses about the ankle fusion site.
Key words: ankle arthrodesis, internal fixation, new technique, union.
Introduction The clinical role of ankle arthroplasty is ill defined and ankle arthrodesis remains the definitive treatment for intractable pain of post-traumatic and degenerative osteo-arthritis, and for some cases of rheumatoid arthritis. Numerous surgical techniques for ankle arthrodesis have been described. These techniques include Gallie's original technique' and the use of the Charnley compression external f i ~ a t e u r . More ~ recently, internal fixation techniques which produce a more rigid compression system have been de~cribed.~-'"Complications of ankle arthrodesis include non-union and malunion, sepsis and continuing pain. Sepsis rates as high as 23%",'* and non-union rates ranging from 6'' to 35% l 4 have been reported. In general, the incidence of non-union has diminished with the introduction of internal compression techniques. The technique described here is surgically straightforward. It has been employed at the Royal North Shore Hospital (RNSH) for the past 5 years, with a 92% union rate and minimal complications.
'
Methods The study was performed at the RNSH of Sydney during a 5 year period. Twelve ankle arthrodeses were performed by the senior surgeon (D.H.S) using the technique described. Each patient was assessed clinically and radiologically with follow-up ranging from 18 months to Correspondence: Dr D. H. Sonnabend. Suite 12/6, Mclntoah St, Chatswood, NSW 2067, Australia.
Accepted for publication 11 June 1992
3 years. Of the 12 patients in the series, seven were female. Patients' ages ranged from 20 to 76 years, with an average of 54 years.
Surgical technique This technique employs three transfixion screws, placed across the tibiotalar plane. Two screws are inserted from the posterior aspect of the tibia, distally and forwards across the fusion plane into the remaining body and neck of the talus. One screw is inserted across the fusion plane in the mid-line, from the anterior surface of the tibial metaphysis distally and posteriorly into the body of the talus. Fixation with the three screws provides good compression and adequate resistance to rotatory and angulatory stresses. Attention to the details described below enables easy precise control of the fusion position. A longitudinal anterior approach to the ankle is employed, just lateral to the anterior neurovascular bundle. Spike retractors are placed subperiosteally , taking particular care to avoid the posterior tibial neurovascular bundle. Two large parallel longitudinal notches are cut from the distal tibia, across the ankle joint, on to the dome of the talus (Fig. 1). If possible, these notches are cut with the ankle joint in the neutral position. They subsequently guide alignment of the arthrodesis, and may need to be 'deepened' as the operation proceeds. The tibial and talar arthrodesis surfaces are then prepared. The tibial surface i s cut first, with an oscillating saw. The saw blade is carefully aligned, perpendicular to the long axis of the tibia, and as little bone as possible is resected, to maximize ultimate leg length. To minimize bone resection, it may be necessary to repeat the distal tibial cut several times, with incremental increases in bone resection. Any
966
cancellous bone removed from the anterior lip of the distal tibia is kept for later grafting. The posterior lip of the distal tibia may be left in situ until after the talar cut, when access to the posterior lip is easier. With the ankle held in the desired alignment, the tibial cut then serves as a guide, and the talar dome is cut with an oscillating saw held parallel to the prepared tibial surface. The starting point for the talar cut anteriorly is the line between the two prepared notches. This minimizes bone resection (Fig. 2).
Fig. 1. Matching A 1 to B I and A2 to B2 ensures correct rotational alignment of foot.
Fig. 2. Matching A to B ensures anteroposterior positioning of foot on tibia is correct.
SONNABEND AND DUCKWORTH
At this stage, if necessary, the posterior tibial lip can be resected. In firm osteo-arthritic bone, laminar spreaders may improve access. In osteoporotic bones, such as that of patients with rheumatoid disease, an assistant pulls longitudinally on the heel to maximize access. Again, any cancellous bone resected from the tibial lip is kept for grafting. If appropriate, the articular surfaces of the malleoli are resected, and the medial and lateral cortices of the talar body are disrupted with either a burr or osteotome. At this stage, the position of the arthrodesis is reviewed. The adequate apposition of two planar surfaces is ensured. The arthrodesis is positioned in neutral flexion and, using the pre-cut notches as guides, care is taken to ensure that the talus is not moved forward on the tibia. (If anything, the talar surface may be displaced some millimetres behind its anatomical position to reduce the ultimate length of the forefoot, and facilitate normal gait.) Again, using the notches as guides, the rotation of the talus on the tibia is adjusted to the physiological position or, if anything, into a few degrees of external rotation. When the surgical team is happy with the alignment, and satisfied that it can be easily reproduced, the arthrodesis space is held open and screw fixation is prepared. The use of cannulated 6.5mm screws facilitates this procedure enormously. Two guidewires are placed retrograde through the cut tibial surface, to emerge through the posterior tibia1 cortex, one medial and one lateral to the Achilles tendon. The wires are advanced through the skin until the distal ends are flush with the cut tibial surface. The site of insertion is determined by observing where the talar and tibial surfaces contact. Similarly, the angle of insertion is determined by observing the angle of the talar neck on radiograph. The guidewires should diverge slightly as they are drilled into the tibia. They will subsequently converge in the talus. A third wire is inserted from the mid-line of the tibia anteriorly, approximately 3 cm above the distal end of the tibia. It is drilled distally and posteriorly until it emerges in the middle of the cut tibial surface. The arthrodesis is then reduced, and all three wires are drilled across the arthrodesis plane into the talus. The distance each wire is advanced into the talus is measured and recorded by the scout nurse (the approximate distances may be predetermined by careful review of the pre-operative X-rays). The arthrodesis position is checked clinically and, if it is satisfactory, the location and length of each wire is checked by either image intensifier or plain X-ray. This step is important. After any necessary adjustment of wiring, cannulated 6.5 mm cancellous screws of appropriate length are placed across the arthrodesis plane. Again screw position and length is reviewed radio-
ANKLE ARTHRODESIS
967
logically. To achieve compression, it is obviously important that the entire thread of each screw is in talar bone and does not cross the arthrodesis plane. Cancellous bone taken from the resected tibia1 lips is packed into the spaces between the malleoli and the body of the talus. The wound is closed by interrupted skin sutures, without drainage. A plaster of Paris backslab is applied for the first 48 h, during which time the foot is elevated. The dressing is then changed and a well fitted short-leg plaster case is applied. The patient is encouraged to mobilize non-weight bearing, and is generally discharged from hospital 3 days postoperatively.
Results Twelve consecutive cases of ankle arthrodesis were studied. The indications for ankle arthrodesis were post-traumatic degerative arthritis (eight cases), primary osteo-arthritis (three cases) and chronic infected non-union following failed arthrodesis elsewhere (one case). Eleven of the 12 cases (92%) proceeded to solid fusion (Fig. 3). The Mazur grading system, based on patient evaluation and clinical examination, was used to assess results.” According to the Mazur grading, there were nine ‘good or excellent’ results, two ‘fair’ results and one ‘poor’ result. The poor result was in an insulin dependent diabetic who, despite solid union on X-ray, continues to complain of hindfoot pain on bearing weight. The remaining 1 1 patients were pleased although two had only ‘fair’ results. These two patients had both been treated for post-traumatic degenerative arthritis. They both went on to solid fusion but continued to experience some hindfoot discomfort which was, subjectively, about 50% less severe than pre-operatively . Assessed both clinically and radiologically, the majority of ankles fused in neutral position (eight cases). The remaining four cases, including the one fibrous ankylosis, were within 5 degrees of valgusl varus from neutral, with one case in 5 degrees of plantar flexion. No ankles fused with any degree of dorsiflexion. Each patient was immobilized in a short-leg plaster for a period of 6-10 weeks. There were no cases of infection, acute or chronic. Eleven of the 12 arthrodeses united clinically and radiographically and the one patient who remained radiographically un-united developed a pain-free fibrous ankylosis. He was very pleased with his result, and rated ‘excellent’ on the Mazur scale. The only remaining symptom experienced by some patients was limitation of movement in the adjacent subtalar joint (STJ). Some patients (50%) had some limitation of STJ movement. Four of
Fig. 3. A typical radiograph of an ankle fusion 1 year postoperatively. (The apparent trangression of the subtalar joint by the anterior screw IS artefactual.)
these six lost up to 50% of STJ movement and two had lost up to 25% of STJ movement. Follow-up revealed no problems related to the screw fixation. There were no instances of loss of alignment or loosening of fixation screws.
968
SONNABEND AND DUCKWORTH
Discussion
2 GALLIE W. E. (1948) Arthrodesis of the Ankle Joint. J . Bone Joint Surg. 30-B, 618-21,
A successful ankle arthrodesis requires bony coapT. C. & MCCONN~LL J . C. M. J . , BEELER 3 STEWART tation, compmsion and rigid immobilization.'o Dur(1983) Compression arthrodesis of the ankle. J . Bone ing the past 45 years various surgical procedures Joint Surg. 65A. 219-25. G . M. & HEIPLEK . G. R. E., BALOURDAS 4 MARCUS have been recommended for ankle arthrodesis. In (1983) Ankle arthrodesis by chevron fusion with inthe past 5 years, the literature has favoured internal ternal fixation and bone grafting. J . Bone Joint Surg. fixation over external fixatiodcompression because 65A. 833-8. of significantly lower complication rates and high 5 Ross S. D. K. & MATTAJ . (1985) Internal compression fusion rates.'.'' The surgical technique of internal arthrodesis of the ankle. Clin Orthop. 199, 54-60. fixation described here, using cannulated cancellous 6 WELMR. (1990) The results of ankle arthrodesis. screws across the tibiotalar plane, provides such J . Bone Joint Surg. 72B. 141-3. compression. D. B . , MARKOLF K. L. & CRACCHIOLO A. 7. THORDARSON (1990) Arthrodesis of the ankle with cancellous bone Maurer and Moeckel have described similar screws and fibular strut graft. J . Bone Joint Surg. methods of Our method differs in 72A, 1359-63. the surgical exposure and preparation of the fusion S . T . , MAYOK. A . & SANGWEORLAN 8 . HOLTE., HANSEN bed and in the insertion technique of the cannulated B . J . (1991). Ankle arthrodesis using internal screw screws. fixation. Clin. Orthop. 268, 21-8. The 92% fusion rate in this series compares faB . H., PAITERSON B. M., INCLISA. E. & 9. MOECKEL vourably with other recently reported ~ e r i e s . ~ . ~ . ~ ' ~ ~ SCULCO ~ , ' ~ T . P. (1991) Ankle arthrodesis. A compariThe 75% 'good to excellent' results as assessed by son of internal and external fixation. Clin. Orthop. the Mazur grading system, also compares favour268, 78-83. R. C., CIMINU W. R., Cox C. V . & SATOW 10. MAURER ably. The two patients with 'fair' results regarded G . K. (1991). Transarticular cross-screw fixation their level of pain as being reduced by more than A technique of ankle arthrodesis. Clin. Orthop. 268, so%, and were satisfied with their results. No 56-64. major complications were seen in this series. The B . F. & WIEVEMAN G. P. (1980) Complica1 1 . MORREY only minor complaint was that of residual subtalar tions and Long-Term Results of Ankle Arthrodeses discomfort, which we believe was present preFollowing Trauma. J . Bone Joint Surg. 62A, 771-84. operatively in the patients concerned. The method . H. R. B . & R ~ R A B E C K 12. LYNCHA. F., BOURNE of ankle arthrodesis described here i s relatively (1988) The long term results of ankle arthrodesis. J . Bone JointSurg. 70B, 113-16. simple and has produced satisfying results. Acknowledgement The authors thank Professor S. T. Hansen of Seattle for his advice. This technique of ankle fusion was developed after discussion with Professor Hansen.
References 1. GROTHH. E. & FITCHH. F. (1987) Salvage procedures for complications of total ankle arthroplasty . Clin.Orthop. 224, 244-8.
D. A , , CLAYTON M. L., WONGD. A , , MACK 13. DENNIS R. P. & SUSMAN M. H. (1990) Internal fixation compression arthrodesis of the ankle. Clin. Orthop. 253, 212-20. R. J . (1986) Ankle arthrodesis, problems and 14. HAGEN pitfalls. Clin. Orthop. 155, 152-62. 15. MAZURJ . M . , SCHWARTZ E. & SIMON S . R. (1979) Ankle arthrodesis. J . Bone Joint Surg. 61A, 964-75. P. E. (1991) An overview of ankle arth16. SCRANTON rodesis. Clin. Orthop. 268. 96-101.
965
1992,62,965-968
SURGICAL TECHNIQUE A NEW TECHNIQUE OF ANKLE ARTHRODESIS D. H. SONNABEND AND D. DUCKWORTH Department of Orthopaedic und Truumatic Surgery, The Royal North Shore Hospital of Sydney, New South Wales, Austruliu A new technique of ankle arthrodesis is described and the results of 12 consecutive procedures are assessed. The method described employs three cannulated transfixion screws and an anterior approach to the ankle. Eleven of the 12 ankles proceeded to solid fusion. One patient developed a painless fibrous non-union. There were no other significant complications. This simple technique provides good compression and adequate resistance to rotatory and angulatory stresses about the ankle fusion site.
Key words: ankle arthrodesis, internal fixation, new technique, union.
Introduction The clinical role of ankle arthroplasty is ill defined and ankle arthrodesis remains the definitive treatment for intractable pain of post-traumatic and degenerative osteo-arthritis, and for some cases of rheumatoid arthritis. Numerous surgical techniques for ankle arthrodesis have been described. These techniques include Gallie's original technique' and the use of the Charnley compression external f i ~ a t e u r . More ~ recently, internal fixation techniques which produce a more rigid compression system have been de~cribed.~-'"Complications of ankle arthrodesis include non-union and malunion, sepsis and continuing pain. Sepsis rates as high as 23%",'* and non-union rates ranging from 6'' to 35% l 4 have been reported. In general, the incidence of non-union has diminished with the introduction of internal compression techniques. The technique described here is surgically straightforward. It has been employed at the Royal North Shore Hospital (RNSH) for the past 5 years, with a 92% union rate and minimal complications.
'
Methods The study was performed at the RNSH of Sydney during a 5 year period. Twelve ankle arthrodeses were performed by the senior surgeon (D.H.S) using the technique described. Each patient was assessed clinically and radiologically with follow-up ranging from 18 months to Correspondence: Dr D. H. Sonnabend. Suite 12/6, Mclntoah St, Chatswood, NSW 2067, Australia.
Accepted for publication 11 June 1992
3 years. Of the 12 patients in the series, seven were female. Patients' ages ranged from 20 to 76 years, with an average of 54 years.
Surgical technique This technique employs three transfixion screws, placed across the tibiotalar plane. Two screws are inserted from the posterior aspect of the tibia, distally and forwards across the fusion plane into the remaining body and neck of the talus. One screw is inserted across the fusion plane in the mid-line, from the anterior surface of the tibial metaphysis distally and posteriorly into the body of the talus. Fixation with the three screws provides good compression and adequate resistance to rotatory and angulatory stresses. Attention to the details described below enables easy precise control of the fusion position. A longitudinal anterior approach to the ankle is employed, just lateral to the anterior neurovascular bundle. Spike retractors are placed subperiosteally , taking particular care to avoid the posterior tibial neurovascular bundle. Two large parallel longitudinal notches are cut from the distal tibia, across the ankle joint, on to the dome of the talus (Fig. 1). If possible, these notches are cut with the ankle joint in the neutral position. They subsequently guide alignment of the arthrodesis, and may need to be 'deepened' as the operation proceeds. The tibial and talar arthrodesis surfaces are then prepared. The tibial surface i s cut first, with an oscillating saw. The saw blade is carefully aligned, perpendicular to the long axis of the tibia, and as little bone as possible is resected, to maximize ultimate leg length. To minimize bone resection, it may be necessary to repeat the distal tibial cut several times, with incremental increases in bone resection. Any
966
cancellous bone removed from the anterior lip of the distal tibia is kept for later grafting. The posterior lip of the distal tibia may be left in situ until after the talar cut, when access to the posterior lip is easier. With the ankle held in the desired alignment, the tibial cut then serves as a guide, and the talar dome is cut with an oscillating saw held parallel to the prepared tibial surface. The starting point for the talar cut anteriorly is the line between the two prepared notches. This minimizes bone resection (Fig. 2).
Fig. 1. Matching A 1 to B I and A2 to B2 ensures correct rotational alignment of foot.
Fig. 2. Matching A to B ensures anteroposterior positioning of foot on tibia is correct.
SONNABEND AND DUCKWORTH
At this stage, if necessary, the posterior tibial lip can be resected. In firm osteo-arthritic bone, laminar spreaders may improve access. In osteoporotic bones, such as that of patients with rheumatoid disease, an assistant pulls longitudinally on the heel to maximize access. Again, any cancellous bone resected from the tibial lip is kept for grafting. If appropriate, the articular surfaces of the malleoli are resected, and the medial and lateral cortices of the talar body are disrupted with either a burr or osteotome. At this stage, the position of the arthrodesis is reviewed. The adequate apposition of two planar surfaces is ensured. The arthrodesis is positioned in neutral flexion and, using the pre-cut notches as guides, care is taken to ensure that the talus is not moved forward on the tibia. (If anything, the talar surface may be displaced some millimetres behind its anatomical position to reduce the ultimate length of the forefoot, and facilitate normal gait.) Again, using the notches as guides, the rotation of the talus on the tibia is adjusted to the physiological position or, if anything, into a few degrees of external rotation. When the surgical team is happy with the alignment, and satisfied that it can be easily reproduced, the arthrodesis space is held open and screw fixation is prepared. The use of cannulated 6.5mm screws facilitates this procedure enormously. Two guidewires are placed retrograde through the cut tibial surface, to emerge through the posterior tibia1 cortex, one medial and one lateral to the Achilles tendon. The wires are advanced through the skin until the distal ends are flush with the cut tibial surface. The site of insertion is determined by observing where the talar and tibial surfaces contact. Similarly, the angle of insertion is determined by observing the angle of the talar neck on radiograph. The guidewires should diverge slightly as they are drilled into the tibia. They will subsequently converge in the talus. A third wire is inserted from the mid-line of the tibia anteriorly, approximately 3 cm above the distal end of the tibia. It is drilled distally and posteriorly until it emerges in the middle of the cut tibial surface. The arthrodesis is then reduced, and all three wires are drilled across the arthrodesis plane into the talus. The distance each wire is advanced into the talus is measured and recorded by the scout nurse (the approximate distances may be predetermined by careful review of the pre-operative X-rays). The arthrodesis position is checked clinically and, if it is satisfactory, the location and length of each wire is checked by either image intensifier or plain X-ray. This step is important. After any necessary adjustment of wiring, cannulated 6.5 mm cancellous screws of appropriate length are placed across the arthrodesis plane. Again screw position and length is reviewed radio-
ANKLE ARTHRODESIS
967
logically. To achieve compression, it is obviously important that the entire thread of each screw is in talar bone and does not cross the arthrodesis plane. Cancellous bone taken from the resected tibia1 lips is packed into the spaces between the malleoli and the body of the talus. The wound is closed by interrupted skin sutures, without drainage. A plaster of Paris backslab is applied for the first 48 h, during which time the foot is elevated. The dressing is then changed and a well fitted short-leg plaster case is applied. The patient is encouraged to mobilize non-weight bearing, and is generally discharged from hospital 3 days postoperatively.
Results Twelve consecutive cases of ankle arthrodesis were studied. The indications for ankle arthrodesis were post-traumatic degerative arthritis (eight cases), primary osteo-arthritis (three cases) and chronic infected non-union following failed arthrodesis elsewhere (one case). Eleven of the 12 cases (92%) proceeded to solid fusion (Fig. 3). The Mazur grading system, based on patient evaluation and clinical examination, was used to assess results.” According to the Mazur grading, there were nine ‘good or excellent’ results, two ‘fair’ results and one ‘poor’ result. The poor result was in an insulin dependent diabetic who, despite solid union on X-ray, continues to complain of hindfoot pain on bearing weight. The remaining 1 1 patients were pleased although two had only ‘fair’ results. These two patients had both been treated for post-traumatic degenerative arthritis. They both went on to solid fusion but continued to experience some hindfoot discomfort which was, subjectively, about 50% less severe than pre-operatively . Assessed both clinically and radiologically, the majority of ankles fused in neutral position (eight cases). The remaining four cases, including the one fibrous ankylosis, were within 5 degrees of valgusl varus from neutral, with one case in 5 degrees of plantar flexion. No ankles fused with any degree of dorsiflexion. Each patient was immobilized in a short-leg plaster for a period of 6-10 weeks. There were no cases of infection, acute or chronic. Eleven of the 12 arthrodeses united clinically and radiographically and the one patient who remained radiographically un-united developed a pain-free fibrous ankylosis. He was very pleased with his result, and rated ‘excellent’ on the Mazur scale. The only remaining symptom experienced by some patients was limitation of movement in the adjacent subtalar joint (STJ). Some patients (50%) had some limitation of STJ movement. Four of
Fig. 3. A typical radiograph of an ankle fusion 1 year postoperatively. (The apparent trangression of the subtalar joint by the anterior screw IS artefactual.)
these six lost up to 50% of STJ movement and two had lost up to 25% of STJ movement. Follow-up revealed no problems related to the screw fixation. There were no instances of loss of alignment or loosening of fixation screws.
968
SONNABEND AND DUCKWORTH
Discussion
2 GALLIE W. E. (1948) Arthrodesis of the Ankle Joint. J . Bone Joint Surg. 30-B, 618-21,
A successful ankle arthrodesis requires bony coapT. C. & MCCONN~LL J . C. M. J . , BEELER 3 STEWART tation, compmsion and rigid immobilization.'o Dur(1983) Compression arthrodesis of the ankle. J . Bone ing the past 45 years various surgical procedures Joint Surg. 65A. 219-25. G . M. & HEIPLEK . G. R. E., BALOURDAS 4 MARCUS have been recommended for ankle arthrodesis. In (1983) Ankle arthrodesis by chevron fusion with inthe past 5 years, the literature has favoured internal ternal fixation and bone grafting. J . Bone Joint Surg. fixation over external fixatiodcompression because 65A. 833-8. of significantly lower complication rates and high 5 Ross S. D. K. & MATTAJ . (1985) Internal compression fusion rates.'.'' The surgical technique of internal arthrodesis of the ankle. Clin Orthop. 199, 54-60. fixation described here, using cannulated cancellous 6 WELMR. (1990) The results of ankle arthrodesis. screws across the tibiotalar plane, provides such J . Bone Joint Surg. 72B. 141-3. compression. D. B . , MARKOLF K. L. & CRACCHIOLO A. 7. THORDARSON (1990) Arthrodesis of the ankle with cancellous bone Maurer and Moeckel have described similar screws and fibular strut graft. J . Bone Joint Surg. methods of Our method differs in 72A, 1359-63. the surgical exposure and preparation of the fusion S . T . , MAYOK. A . & SANGWEORLAN 8 . HOLTE., HANSEN bed and in the insertion technique of the cannulated B . J . (1991). Ankle arthrodesis using internal screw screws. fixation. Clin. Orthop. 268, 21-8. The 92% fusion rate in this series compares faB . H., PAITERSON B. M., INCLISA. E. & 9. MOECKEL vourably with other recently reported ~ e r i e s . ~ . ~ . ~ ' ~ ~ SCULCO ~ , ' ~ T . P. (1991) Ankle arthrodesis. A compariThe 75% 'good to excellent' results as assessed by son of internal and external fixation. Clin. Orthop. the Mazur grading system, also compares favour268, 78-83. R. C., CIMINU W. R., Cox C. V . & SATOW 10. MAURER ably. The two patients with 'fair' results regarded G . K. (1991). Transarticular cross-screw fixation their level of pain as being reduced by more than A technique of ankle arthrodesis. Clin. Orthop. 268, so%, and were satisfied with their results. No 56-64. major complications were seen in this series. The B . F. & WIEVEMAN G. P. (1980) Complica1 1 . MORREY only minor complaint was that of residual subtalar tions and Long-Term Results of Ankle Arthrodeses discomfort, which we believe was present preFollowing Trauma. J . Bone Joint Surg. 62A, 771-84. operatively in the patients concerned. The method . H. R. B . & R ~ R A B E C K 12. LYNCHA. F., BOURNE of ankle arthrodesis described here i s relatively (1988) The long term results of ankle arthrodesis. J . Bone JointSurg. 70B, 113-16. simple and has produced satisfying results. Acknowledgement The authors thank Professor S. T. Hansen of Seattle for his advice. This technique of ankle fusion was developed after discussion with Professor Hansen.
References 1. GROTHH. E. & FITCHH. F. (1987) Salvage procedures for complications of total ankle arthroplasty . Clin.Orthop. 224, 244-8.
D. A , , CLAYTON M. L., WONGD. A , , MACK 13. DENNIS R. P. & SUSMAN M. H. (1990) Internal fixation compression arthrodesis of the ankle. Clin. Orthop. 253, 212-20. R. J . (1986) Ankle arthrodesis, problems and 14. HAGEN pitfalls. Clin. Orthop. 155, 152-62. 15. MAZURJ . M . , SCHWARTZ E. & SIMON S . R. (1979) Ankle arthrodesis. J . Bone Joint Surg. 61A, 964-75. P. E. (1991) An overview of ankle arth16. SCRANTON rodesis. Clin. Orthop. 268. 96-101.
