- Email: [email protected]
Non-union of acetabular fractures
Injury, Int. J. Care Injured (2004) 35, 787—790
Non-union of acetabular fractures K. Mohanty*, W. Taha, J.N. Powell Department of Trauma and Orthopaedics, Foothills Hospital, Calgary, Alberta, Canada Accepted 5 November 2003
KEYWORDS Acetabulum; Fracture; Non-union; Transverse; Letournel
Summary Non-unions of acetabulum are rare. Seven cases of acetabular non-unions are reported in this retrospective study. Five out of our seven patients had either transverse or associated transverse with posterior wall fractures. All patients had surgical stabilisation of their index fractures. A diagnosis of non-union was made at an average of 5.8 months from the original injury based on clinical and radiological features. Five of the six patients who underwent re-stabilisation and bone grafting of the non-union healed where as the remaining one did not heal after two attempts at restabilisation and was treated with excision arthroplasty. Two of the healed five, subsequently developed osteoarthritis and had total hip arthroplasty where as one patient had already developed degeneration of his hip at the time of diagnosis and hence treated with total hip arthroplasty. Analysis of the non-unions confirmed that fixation was unstable in all with residual displacement seen in two of them. In conclusion acetabular fracture non-union appear to be associated with transverse fractures and unstable fixation. ß 2004 Elsevier Ltd. All rights reserved.
Introduction The management of acetabular fractures has evolved in the last four decades. Letournel4 has defined the patho-anatomy and radiology of these fractures and has classified acetabular injury. Anatomic reconstruction of the articular surface along with stable internal fixation of these fractures has been shown to produce less pain, better function and prevent secondary osteoarthrosis of the hip joint.8,5,9,10,19,12 Based on these studies, operative management of displaced fractures of acetabulum has now become a ‘gold standard’. Non-union of acetabular fracture is uncommon. They are even rarer after operative fixation of these fractures. Letournel defined non-union of acetabulum as a fracture that has remained unhealed for *Corresponding author. Present address: 44 Youghal Close (Princess Gate), Pontprennau, Cardiff CF23 8RN, UK. Tel.: þ44-029-20-541799; fax: þ44-029-20-541799. E-mail address: [email protected] (K. Mohanty).
longer than 4 months after the injury. In their textbook he quoted a non-union rate of 0.7% in a series of 569 acetabular fractures.6 There are very few reports of acetabular non-union in the literature. In this retrospective review, we present seven cases of acetabular non-union encountered by the senior author over a period of 8 years. We identify the fracture patterns in these cases, discuss the fixation techniques, surgical treatment of nonunion and suggest a strategy for management of this uncommon problem.
Patient and method From 1994 through 2001, the senior author (JNP) managed seven cases of acetabular non-union. In this period, approximately two hundred acetabular fractures were treated at this level one trauma centre. There were four males and three females.
0020–1383/$ — see front matter ß 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2003.11.022
788
K. Mohanty et al.
The average age at the time of initial injury was 38.4 years (range 23—56 years). All seven patients suffered high-energy injury. The initial evaluation included full physical examination, antero-posterior and Judet views of pelvis and CT scans of the pelvis. The fractures were classified as per Letournel’s classification system.4 The indications for the initial operative management of these cases were joint incongruity, joint instability and retained intraarticular fragments within in the weight-bearing area of the hip joint. Six of our seven patients met at least one of the above-mentioned criteria and were operated upon. One patient had an undisplaced fracture and hence treated with initial bed rest, followed by nonweight bearing mobilization. However, follow-up X-ray showed displacement of fracture at 3 weeks and hence surgical stabilization was carried out at 4 weeks post-injury. A Kocher—Langenbach approach was used for four, an extended ilio-femoral and triradiate approach was chosen for one each of the remaining patients and a combined Kocher— Langenbach and ilioinguinal approach was selected for one patient. All patients were followed up at 2, 6 and 10 weeks post-operatively and than every 3 months after fixation of their acetabular fractures. All patients were advised to remain non-weight bearing for at least 10 weeks post-operatively; following which progressive weight bearing was commenced. Range of motion as well as strengthening exercises were started at 6 weeks. Follow-up radiographs included antero-posterior and Judet views. A diagnosis of non-union was considered at 16th post-operative week if there were presence of clin-
Table 1
ical signs such as persistent pain and click or no evidence of bone healing or bridging on the followup radiographs. Increase in the size of a previous gap or appearance of a new gap or step was also taken into consideration. When non-union was suspected clinically or radiologically, a confirmatory CT scan was obtained in each case. The clinical files and radiographs of all seven patients were reviewed to determine the mechanism of injury, type of fracture, method of fixation, co morbidity, post-operative course and other factor that could affect fracture healing. The records of all seven patients were complete till the final outcome.
Result All seven patients were victims of high-energy accidents. Two patients had pure transverse fractures, three had transverse þ posterior wall fracture, where as one each of the remaining two had associated both column fracture and T-type fracture of the acetabulum, respectively. (Table 1). None of the patients were diabetic or steroid user. Two of the seven were smokers. Four patients in this group had sustained associated injuries, two had associated pelvic ring injuries where as other two had injuries to the lower limbs. Two patients had sciatic nerve injuries on presentation. All patients received Indomethacin in the post-operative period as prophylaxis against heterotrophic ossification. On evaluating the fixation technique, two cases were found to have no lag screws across either column, four had lag screws only across the poster-
Patient details
Number Age/sex
Fracture type
Diagnosis of non-union after index fracture (months)
Non-union surgery details
Final outcome
1
23/male
8
52/male
7
3
34/female
Transverse
4
4 5
24/female 56/male
7 5
6
45/female
7
35/male
T-type Transverse þ posterior wall Associated both column Transverse þ posterior wall
Re-fixation with bone grafting Re-fixation with bone grafting followed by THR Two failed attempts at re-fixation excision arthroplasty Re-fixation þ bone grafting THR
Healed
2
Transverse þ posterior wall Transverse
6 4
Re-fixation þ bone grafting followed by THR Re-fixation þ bone grafting
Asymptomatic Mobilizing with shoe raise Healed Asymptomatic Asymptomatic Healed
Non-union of acetabular fractures
ior column and only one patient had lag screws across both columns. The immediate postoperative radiographs were satisfactory in five cases. Gaps of 3 and 4 mm were found in the other two cases. No significant step was found in any of the cases. All patients complained of persistent pain in the post-operative period. The diagnosis of non-union was made at an average duration of 5.8 months after the index fracture (range 4—8 months). All patients complained of pain on weight bearing. Two patients complained of additional pain when getting up from sitting position and clicking sensation. The follow-up X-rays and CT scans showed persistent fracture lines all cases. In two patients, there was evidence of hardware failure at the time of the diagnosis. Six patients were treated with debridement of non-union, bone grafting and revision of fixation out of which five healed. However, two of the five healed patients showed signs joint incongruency on follow-up X-rays and subsequently developed secondary osteoarthrosis and were converted to total hip arthroplasty. The remaining one patient was morbidly obese and had psychiatric illness and hence treated electively with excision arthroplasty after two failed attempts of re-stabilisation and bone grafting. One patient showed deformity of femoral head and onset of degenerative changes at the time of diagnosis and underwent total hip arthroplasty (Table 1). The non-union in this case was exposed through a Kocher—Langenbach approach, the metal work taken out and the posterior column was restabilized with plate and screws after freshening the fracture ends. The non-union was bone grafted with cancellous graft obtained from the patients own femoral head and an uncemented cup was implanted along with an uncemented stem. All patients were pain free and mobilising full weight bearing at a minimum follow-up time of 1 year (range 1—5 years) with the exception of the patient with excision arthroplasty.
Discussion Letournel defined non-union of acetabular fracture as fracture that has remained ununited after 4 months from the initial injury. Non-union is clinically characterised by variable amount of pain, limp and associated painful range of motion. He reported treating 11 non-unions.7 In his series, there were three posterior column fractures, six transverse fractures and remaining two of transverse with posterior wall type. According to Letournel,7 the X-ray appearance of non-union is fairly characteristic with clearly visible fracture lines, sclerotic
789
margins and sometimes with hypertrophic, irregular edges. In his experience, established non-union of acetabulum never united spontaneously and often there was rapid onset of arthritis making the joint reconstruction impossible. The recommended treatment is operative with decortication of nonunion, excision of fibrous tissue from the non-union site and bone grafting combined with stable internal fixation. Letournel recommends an extensile approach like an extended ilio-femoral approach to deal with most non-unions. The incidence of acetabular non-unions reported in the literature is rare. Mears et al.14 reported one case of non-union in their series of 100 acetabular fractures. Helfet and Schmeling3 reported 0% nonunion rate in their series of 127 surgically treated acetabular fractures. Matta10 also did not find any non-unions in his series of 259 acetabular fractures. Mayo12 in his personal series of 163 acetabular fractures has reported one case of delayed union and two cases of non-union. If Letournel’s definition of non-union is adhered to, than the delayed union in this group could be classified as non-union. In Mayo’s series, two of the three delayed/non-unions had transverse and transverse with posterior wall configuration, respectively. Zura and Kahler20 recently reported percutaneous, computer-assisted fixation for a transverse non-union. The limited data on non-unions of acetabulum indicates towards a predilection of transverse fractures and its associated patterns. In Letournel’s experience, 8/11 of the non-unions were either transverse or associated transverse with posterior wall patterns. In Mayo’s series, 2/3 of non-unions were transverse patterns. In our series, 5/7 of nonunions were either transverse or associated transverse with posterior wall fractures. Judet and Letournel6 have included transverse fracture in their elementary group because of the ‘‘simplicity of the fracture line’’. However, compared with other elementary fracture patterns, transverse fracture divides both columns of the acetabulum, and often involves the weight-bearing dome of the acetabulum. The ichio-pubic segment often rotates around a vertical and a horizontal axis located at the pubic symphysis subjecting it to tilt and displace inwards. Accurate reduction and stable internal fixation requires an adequate approach to control both limbs of the fracture and lag screw fixation across both column supplemented by neutralisation plate.6 In order to achieve stable fixation, Letournel recommended extended iliofemoral approach for stabilisation of trans-tectal transverse fractures. In our series, review of the fixation technique revealed that there was only one patient who had
790
lag screw across both his columns, two of the cases had no lag screws across either columns and the remaining four had lag screws across their posterior column. We believe inadequate fixation of both columns could have led to non-union in these cases. Currently we routinely fix both columns with lag screws along with supplementary plate and screws to one of the columns, when dealing with transverse fractures. Cheng et al.2 in their biomechanical study have shown that plate and lag screw construct showed greater yield strength as compared to lag screws alone. Advances in technology including fluoroscopy guided percutaneous fixation and computer-assisted surgery has helped us achieve better fixation of these fractures with out opting for an extensile approach. With our current approach we have not encountered any non-unions in the last 2 years. All our patients received Indomethacin as a prophylaxis against heterotrophic ossification. The rate of heterotrophic ossification varies from 24 to 60% in the literature and mainly occurs with extensile approaches.11,15,18 There is enough evidence in the literature16,13,17 to recommend indomethacin prophylaxis for posterior and extensile approaches. However, NSAIDs including indomethacin have been shown to retard fracture healing.1 Whether prophylactic indomethacin in our group of patients was causative of non-union or was a significant factor is difficult to comment due to the small number of patients. In conclusion, acetabular non-union is uncommon but has a tendency to occur in transverse fractures and its associated pattern. The patients complains of pain and clicking and a diagnosis can be made on plain X-rays because of persistent fracture lines at 4 months post-injury. We adhere to recommendations of Letournel that these transverse fractures require anatomical reduction and interfragmental compression of fracture lines plus neutralization plate fixation.
References 1. Altman RD, Latta LL, Keer R, Renfree K, Hornicek FJ, Banovac K. Effect of nonsteroidal anti-inflammatory drugs on fracture healing. A laboratory study on rats. J Orthop Trauma 1995;9(5):392—400.
K. Mohanty et al.
2. Cheng JK, Gill SS, Zura RD, Krause WR, Wang GJ. Comparative strength of three methods of fixation of transverse acetabular fractures. Clin Orthop 2001;392(November):433—41. 3. Helfet DL, Schmeling GJ. Management of complex acetabular fractures through single nonextensile exposures. Clin Orthop 1994;305:58—68. 4. Letournel E. Acetabular fractures: classification and management. Clin Orthop 1980;151:81—106. 5. Letournel E. Fractures of the acetabulum. A study of a series of 75 cases. Clin Orthop 1994;305:5—9. 6. Letournel E, Judet R. Fractures of the acetabulum. New York: Springer; 1993. p. 541—3. 7. Letournel E. Diagnosis and treatment of nonunions and malunions of acetabular fractures. Orthop Clin North Am 1990;21:769—88. 8. Matta JM, Anderson LM, Epstein HC, Hendricks P. Fracture of the acetabulum. A retrospective analysis. Clin Orthop 1986;205:230—40. 9. Matta JM, Merrit PO. Displaced acetabular fractures. Clin Orthop 1988;230(May):83—7. 10. Matta JM. Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after injury. J Bone Joint Surg Am 1996;78(November (11)):1632—45. 11. Matta JM. Preliminary results of a prospective randomised study using prophylactic indomethacin. Presented at the 1st International Symposium on Surgical Treatment of Acetabular Fractures. Paris, France, 1993. 12. Mayo KA. Open reduction and internal fixation of fractures of acetabulum. Results in 163 fractures. Clin Orthop 1994; 305(August):31—7. 13. Mclaran AC. Prophylaxis with indometahcin for heterotopic bone. J Bone Joint Surg Am 1990;72A:245—7. 14. Mears DC, Rubash HE, Sawaguchi T. Fractures of the acetabulum. In: The Hip: Proceedings of 13th Open Scientific Meeting of the Hip Society. St. Louis: C.V. Mosby; 1985. p. 95—113. 15. Mears DC, Rubsah HE. Extensile exposure of the pelvis. Contemp Orthop 1983;6:21—31. 16. Moed BR, Letournel E. Combination low dose radiation and indomethacin therapy for the prevention of heterotopic ossification following acetabular fracture surgery. Presented at the 1st International Symposium on Surgical Treatment of Acetabular Fractures. Paris, France, 1993. 17. Moed BR, Maxey JW. The effect of Indomethacin on heterotopic ossification following acetabular fracture surgery. J Orthop Trauma 1993;7:33—8. 18. Reinert CM, Boss MJ, Poka A, Schacherer T, Brumback RJ, Burgess AR. A modified extensile exposure for the treatment of complex or malunited acetabular fractures. J Bone Joint Surg Am 1988;70(3):329—37. 19. Reusch PD, Holdener H, Ciaramitaro M, Mast JW. A prospective study of surgically treated acetabular fractures. Clin Orthop 1994;305:38—46. 20. Zura RD, Kahler DM. A transverse non-union treated with computer- assisted percutaneous internal fixation. A case report. J Bone Joint Surg Am 2000;82(February (2)):219—24.
Non-union of acetabular fractures K. Mohanty*, W. Taha, J.N. Powell Department of Trauma and Orthopaedics, Foothills Hospital, Calgary, Alberta, Canada Accepted 5 November 2003
KEYWORDS Acetabulum; Fracture; Non-union; Transverse; Letournel
Summary Non-unions of acetabulum are rare. Seven cases of acetabular non-unions are reported in this retrospective study. Five out of our seven patients had either transverse or associated transverse with posterior wall fractures. All patients had surgical stabilisation of their index fractures. A diagnosis of non-union was made at an average of 5.8 months from the original injury based on clinical and radiological features. Five of the six patients who underwent re-stabilisation and bone grafting of the non-union healed where as the remaining one did not heal after two attempts at restabilisation and was treated with excision arthroplasty. Two of the healed five, subsequently developed osteoarthritis and had total hip arthroplasty where as one patient had already developed degeneration of his hip at the time of diagnosis and hence treated with total hip arthroplasty. Analysis of the non-unions confirmed that fixation was unstable in all with residual displacement seen in two of them. In conclusion acetabular fracture non-union appear to be associated with transverse fractures and unstable fixation. ß 2004 Elsevier Ltd. All rights reserved.
Introduction The management of acetabular fractures has evolved in the last four decades. Letournel4 has defined the patho-anatomy and radiology of these fractures and has classified acetabular injury. Anatomic reconstruction of the articular surface along with stable internal fixation of these fractures has been shown to produce less pain, better function and prevent secondary osteoarthrosis of the hip joint.8,5,9,10,19,12 Based on these studies, operative management of displaced fractures of acetabulum has now become a ‘gold standard’. Non-union of acetabular fracture is uncommon. They are even rarer after operative fixation of these fractures. Letournel defined non-union of acetabulum as a fracture that has remained unhealed for *Corresponding author. Present address: 44 Youghal Close (Princess Gate), Pontprennau, Cardiff CF23 8RN, UK. Tel.: þ44-029-20-541799; fax: þ44-029-20-541799. E-mail address: [email protected] (K. Mohanty).
longer than 4 months after the injury. In their textbook he quoted a non-union rate of 0.7% in a series of 569 acetabular fractures.6 There are very few reports of acetabular non-union in the literature. In this retrospective review, we present seven cases of acetabular non-union encountered by the senior author over a period of 8 years. We identify the fracture patterns in these cases, discuss the fixation techniques, surgical treatment of nonunion and suggest a strategy for management of this uncommon problem.
Patient and method From 1994 through 2001, the senior author (JNP) managed seven cases of acetabular non-union. In this period, approximately two hundred acetabular fractures were treated at this level one trauma centre. There were four males and three females.
0020–1383/$ — see front matter ß 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2003.11.022
788
K. Mohanty et al.
The average age at the time of initial injury was 38.4 years (range 23—56 years). All seven patients suffered high-energy injury. The initial evaluation included full physical examination, antero-posterior and Judet views of pelvis and CT scans of the pelvis. The fractures were classified as per Letournel’s classification system.4 The indications for the initial operative management of these cases were joint incongruity, joint instability and retained intraarticular fragments within in the weight-bearing area of the hip joint. Six of our seven patients met at least one of the above-mentioned criteria and were operated upon. One patient had an undisplaced fracture and hence treated with initial bed rest, followed by nonweight bearing mobilization. However, follow-up X-ray showed displacement of fracture at 3 weeks and hence surgical stabilization was carried out at 4 weeks post-injury. A Kocher—Langenbach approach was used for four, an extended ilio-femoral and triradiate approach was chosen for one each of the remaining patients and a combined Kocher— Langenbach and ilioinguinal approach was selected for one patient. All patients were followed up at 2, 6 and 10 weeks post-operatively and than every 3 months after fixation of their acetabular fractures. All patients were advised to remain non-weight bearing for at least 10 weeks post-operatively; following which progressive weight bearing was commenced. Range of motion as well as strengthening exercises were started at 6 weeks. Follow-up radiographs included antero-posterior and Judet views. A diagnosis of non-union was considered at 16th post-operative week if there were presence of clin-
Table 1
ical signs such as persistent pain and click or no evidence of bone healing or bridging on the followup radiographs. Increase in the size of a previous gap or appearance of a new gap or step was also taken into consideration. When non-union was suspected clinically or radiologically, a confirmatory CT scan was obtained in each case. The clinical files and radiographs of all seven patients were reviewed to determine the mechanism of injury, type of fracture, method of fixation, co morbidity, post-operative course and other factor that could affect fracture healing. The records of all seven patients were complete till the final outcome.
Result All seven patients were victims of high-energy accidents. Two patients had pure transverse fractures, three had transverse þ posterior wall fracture, where as one each of the remaining two had associated both column fracture and T-type fracture of the acetabulum, respectively. (Table 1). None of the patients were diabetic or steroid user. Two of the seven were smokers. Four patients in this group had sustained associated injuries, two had associated pelvic ring injuries where as other two had injuries to the lower limbs. Two patients had sciatic nerve injuries on presentation. All patients received Indomethacin in the post-operative period as prophylaxis against heterotrophic ossification. On evaluating the fixation technique, two cases were found to have no lag screws across either column, four had lag screws only across the poster-
Patient details
Number Age/sex
Fracture type
Diagnosis of non-union after index fracture (months)
Non-union surgery details
Final outcome
1
23/male
8
52/male
7
3
34/female
Transverse
4
4 5
24/female 56/male
7 5
6
45/female
7
35/male
T-type Transverse þ posterior wall Associated both column Transverse þ posterior wall
Re-fixation with bone grafting Re-fixation with bone grafting followed by THR Two failed attempts at re-fixation excision arthroplasty Re-fixation þ bone grafting THR
Healed
2
Transverse þ posterior wall Transverse
6 4
Re-fixation þ bone grafting followed by THR Re-fixation þ bone grafting
Asymptomatic Mobilizing with shoe raise Healed Asymptomatic Asymptomatic Healed
Non-union of acetabular fractures
ior column and only one patient had lag screws across both columns. The immediate postoperative radiographs were satisfactory in five cases. Gaps of 3 and 4 mm were found in the other two cases. No significant step was found in any of the cases. All patients complained of persistent pain in the post-operative period. The diagnosis of non-union was made at an average duration of 5.8 months after the index fracture (range 4—8 months). All patients complained of pain on weight bearing. Two patients complained of additional pain when getting up from sitting position and clicking sensation. The follow-up X-rays and CT scans showed persistent fracture lines all cases. In two patients, there was evidence of hardware failure at the time of the diagnosis. Six patients were treated with debridement of non-union, bone grafting and revision of fixation out of which five healed. However, two of the five healed patients showed signs joint incongruency on follow-up X-rays and subsequently developed secondary osteoarthrosis and were converted to total hip arthroplasty. The remaining one patient was morbidly obese and had psychiatric illness and hence treated electively with excision arthroplasty after two failed attempts of re-stabilisation and bone grafting. One patient showed deformity of femoral head and onset of degenerative changes at the time of diagnosis and underwent total hip arthroplasty (Table 1). The non-union in this case was exposed through a Kocher—Langenbach approach, the metal work taken out and the posterior column was restabilized with plate and screws after freshening the fracture ends. The non-union was bone grafted with cancellous graft obtained from the patients own femoral head and an uncemented cup was implanted along with an uncemented stem. All patients were pain free and mobilising full weight bearing at a minimum follow-up time of 1 year (range 1—5 years) with the exception of the patient with excision arthroplasty.
Discussion Letournel defined non-union of acetabular fracture as fracture that has remained ununited after 4 months from the initial injury. Non-union is clinically characterised by variable amount of pain, limp and associated painful range of motion. He reported treating 11 non-unions.7 In his series, there were three posterior column fractures, six transverse fractures and remaining two of transverse with posterior wall type. According to Letournel,7 the X-ray appearance of non-union is fairly characteristic with clearly visible fracture lines, sclerotic
789
margins and sometimes with hypertrophic, irregular edges. In his experience, established non-union of acetabulum never united spontaneously and often there was rapid onset of arthritis making the joint reconstruction impossible. The recommended treatment is operative with decortication of nonunion, excision of fibrous tissue from the non-union site and bone grafting combined with stable internal fixation. Letournel recommends an extensile approach like an extended ilio-femoral approach to deal with most non-unions. The incidence of acetabular non-unions reported in the literature is rare. Mears et al.14 reported one case of non-union in their series of 100 acetabular fractures. Helfet and Schmeling3 reported 0% nonunion rate in their series of 127 surgically treated acetabular fractures. Matta10 also did not find any non-unions in his series of 259 acetabular fractures. Mayo12 in his personal series of 163 acetabular fractures has reported one case of delayed union and two cases of non-union. If Letournel’s definition of non-union is adhered to, than the delayed union in this group could be classified as non-union. In Mayo’s series, two of the three delayed/non-unions had transverse and transverse with posterior wall configuration, respectively. Zura and Kahler20 recently reported percutaneous, computer-assisted fixation for a transverse non-union. The limited data on non-unions of acetabulum indicates towards a predilection of transverse fractures and its associated patterns. In Letournel’s experience, 8/11 of the non-unions were either transverse or associated transverse with posterior wall patterns. In Mayo’s series, 2/3 of non-unions were transverse patterns. In our series, 5/7 of nonunions were either transverse or associated transverse with posterior wall fractures. Judet and Letournel6 have included transverse fracture in their elementary group because of the ‘‘simplicity of the fracture line’’. However, compared with other elementary fracture patterns, transverse fracture divides both columns of the acetabulum, and often involves the weight-bearing dome of the acetabulum. The ichio-pubic segment often rotates around a vertical and a horizontal axis located at the pubic symphysis subjecting it to tilt and displace inwards. Accurate reduction and stable internal fixation requires an adequate approach to control both limbs of the fracture and lag screw fixation across both column supplemented by neutralisation plate.6 In order to achieve stable fixation, Letournel recommended extended iliofemoral approach for stabilisation of trans-tectal transverse fractures. In our series, review of the fixation technique revealed that there was only one patient who had
790
lag screw across both his columns, two of the cases had no lag screws across either columns and the remaining four had lag screws across their posterior column. We believe inadequate fixation of both columns could have led to non-union in these cases. Currently we routinely fix both columns with lag screws along with supplementary plate and screws to one of the columns, when dealing with transverse fractures. Cheng et al.2 in their biomechanical study have shown that plate and lag screw construct showed greater yield strength as compared to lag screws alone. Advances in technology including fluoroscopy guided percutaneous fixation and computer-assisted surgery has helped us achieve better fixation of these fractures with out opting for an extensile approach. With our current approach we have not encountered any non-unions in the last 2 years. All our patients received Indomethacin as a prophylaxis against heterotrophic ossification. The rate of heterotrophic ossification varies from 24 to 60% in the literature and mainly occurs with extensile approaches.11,15,18 There is enough evidence in the literature16,13,17 to recommend indomethacin prophylaxis for posterior and extensile approaches. However, NSAIDs including indomethacin have been shown to retard fracture healing.1 Whether prophylactic indomethacin in our group of patients was causative of non-union or was a significant factor is difficult to comment due to the small number of patients. In conclusion, acetabular non-union is uncommon but has a tendency to occur in transverse fractures and its associated pattern. The patients complains of pain and clicking and a diagnosis can be made on plain X-rays because of persistent fracture lines at 4 months post-injury. We adhere to recommendations of Letournel that these transverse fractures require anatomical reduction and interfragmental compression of fracture lines plus neutralization plate fixation.
References 1. Altman RD, Latta LL, Keer R, Renfree K, Hornicek FJ, Banovac K. Effect of nonsteroidal anti-inflammatory drugs on fracture healing. A laboratory study on rats. J Orthop Trauma 1995;9(5):392—400.
K. Mohanty et al.
2. Cheng JK, Gill SS, Zura RD, Krause WR, Wang GJ. Comparative strength of three methods of fixation of transverse acetabular fractures. Clin Orthop 2001;392(November):433—41. 3. Helfet DL, Schmeling GJ. Management of complex acetabular fractures through single nonextensile exposures. Clin Orthop 1994;305:58—68. 4. Letournel E. Acetabular fractures: classification and management. Clin Orthop 1980;151:81—106. 5. Letournel E. Fractures of the acetabulum. A study of a series of 75 cases. Clin Orthop 1994;305:5—9. 6. Letournel E, Judet R. Fractures of the acetabulum. New York: Springer; 1993. p. 541—3. 7. Letournel E. Diagnosis and treatment of nonunions and malunions of acetabular fractures. Orthop Clin North Am 1990;21:769—88. 8. Matta JM, Anderson LM, Epstein HC, Hendricks P. Fracture of the acetabulum. A retrospective analysis. Clin Orthop 1986;205:230—40. 9. Matta JM, Merrit PO. Displaced acetabular fractures. Clin Orthop 1988;230(May):83—7. 10. Matta JM. Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after injury. J Bone Joint Surg Am 1996;78(November (11)):1632—45. 11. Matta JM. Preliminary results of a prospective randomised study using prophylactic indomethacin. Presented at the 1st International Symposium on Surgical Treatment of Acetabular Fractures. Paris, France, 1993. 12. Mayo KA. Open reduction and internal fixation of fractures of acetabulum. Results in 163 fractures. Clin Orthop 1994; 305(August):31—7. 13. Mclaran AC. Prophylaxis with indometahcin for heterotopic bone. J Bone Joint Surg Am 1990;72A:245—7. 14. Mears DC, Rubash HE, Sawaguchi T. Fractures of the acetabulum. In: The Hip: Proceedings of 13th Open Scientific Meeting of the Hip Society. St. Louis: C.V. Mosby; 1985. p. 95—113. 15. Mears DC, Rubsah HE. Extensile exposure of the pelvis. Contemp Orthop 1983;6:21—31. 16. Moed BR, Letournel E. Combination low dose radiation and indomethacin therapy for the prevention of heterotopic ossification following acetabular fracture surgery. Presented at the 1st International Symposium on Surgical Treatment of Acetabular Fractures. Paris, France, 1993. 17. Moed BR, Maxey JW. The effect of Indomethacin on heterotopic ossification following acetabular fracture surgery. J Orthop Trauma 1993;7:33—8. 18. Reinert CM, Boss MJ, Poka A, Schacherer T, Brumback RJ, Burgess AR. A modified extensile exposure for the treatment of complex or malunited acetabular fractures. J Bone Joint Surg Am 1988;70(3):329—37. 19. Reusch PD, Holdener H, Ciaramitaro M, Mast JW. A prospective study of surgically treated acetabular fractures. Clin Orthop 1994;305:38—46. 20. Zura RD, Kahler DM. A transverse non-union treated with computer- assisted percutaneous internal fixation. A case report. J Bone Joint Surg Am 2000;82(February (2)):219—24.