Arch Orthop Trauma Surg (1991) 111:53-57
Arhiw,o,Orthopaedic dTrauma Surgery © Springer-Verlag 1991
Orthopaedic treatment in tibial diaphyseal fractures Risk factors affecting union L. Ferrandez 1, J. Curto 1, J. Sanchez 2, J. Guiral 1, and L. R a m o s 1 Departments of 1Traumatology and Orthopedic Surgery and 2Statistical Mathematics, University Hospital, Salamanca, Spain
Summary. A retrospective of 216 tibial fractures treated orthopedically was carried out. T h e aim was to analyze a set of clinicobiological p a r a m e t e r s that owing to their assumed action on the physiological m o d e l of consolidation can be considered as risk factors to be taken into account in all kinds of o r t h o p e d i c t r e a t m e n t , because they m a y lead to a lengthening of the n o r m a l consolidation time of the fracture. T h e variables analyzed were the following: type o f immobilization, causative agent of the fracture, location of the focus of the fibular fracture, initial displacement, degree of c o n m i n u t i o n , type of w o u n d , type of fracture, a p p e a r a n c e of radiologically observable callus, c o m m e n c e m e n t of weight-bearing, post-fracture h e m a t o m a , s e c o n d a r y displacement, and infection of soft tissues. In the particular case of i m m o bilization by an ischiopedic plaster cast, the following p a r a m e t e r s s h o w e d a greater degree of prognostic significance: initial displacement, s e c o n d a r y displacement, and age.
T h e incidence, variety, and complexity of diaphyseal tibial fractures, t o g e t h e r with c o n t e m p o r a r y therapeutic trends, m e a n that this kind of lesion continues to be of great interest to traumatologists. Shortening, comminution, displacement, and/or interf r a g m e n t a r y r o t a t i o n often characterize the b r e a k i n g of this eccentric b o n e of the leg, which, being s o m e w h a t u n p r o t e c t e d by soft tissues, has a r e d u c e d b l o o d supply f r o m outside the b o n e [24]. T h e functional alteration to the b o n e caused by fracture m e a n s that a m o d e l for curing such lesions is required; this m a y vary according to the characteristics of the lesion to the b o n e and to the softer parts surrounding it [8, 12, 21, 25, 27, 28]. Conservative t r e a t m e n t m a k e s it necessary to consider the reduction and stabilization of the b o n e [1, 3, 7, 9, 22, 28, 33] using for such purposes the stabilizing elastic C h a r n l e y effect of the unlesioned soft tissues [7]; the aim of this w o u l d be to find a biological response in the osteoperiosteal layers [20], thus restoring function and allowing early weight-bearing [11, 14, 26]. Offprint requests to: Prof. L. Ferrandez Portal
T h e alterations in biological organization occasioned by secondary displacements have led to criticisms of the m e t h o d [6, 17, 31, 32], sometimes creating the n e e d for corrective gypsotomies several days after o r t h o p e d i c reduction [5, 9, 19, 33]. All these considerations p r o m p t e d us to investigate the problems involved in the consolidation of diaphyseal tibial fractures and to a t t e m p t to determine the factors affecting the length of time required for b o n e union.
Materials and methods A retrospective study was carried out on a group of 216 patients with complete clinical records who had received orthopedic treatment between 1977 and 1987. After meticulous reduction, an ischiopedic plaster cast was employed as the external system for reducing the fracture. Manifest instability at the focus of the fracture (on clinical exploration) in the sagittal and coronal planes necessitated placement of a Steinmann pin at the level of the anterior tuberosity of the tibia and another distally in the calcaneus. All patients were fitted with a functional plaster so as to be able to bear weight on the injured leg, this being carried out at a mean of 6 weeks (SD _+3 weeks). Diaphyseal fracture was defined as a fracture at least 6 cm from the tibial plate an or at least 6 cm from the tibio-fibulo-astragalar joint (Fig. 1). To classify the location of the loci of the fractures, the anatomical region of the diaphysis was divided into three areas; those that extended between two adjacent areas were classified as such [4]. Fractures of the fibula were classified in a similar way. Initial displacement was evaluated from the emergency radiographs. No displacement was classified as nil, and displacement approaching 1/4 of the diaphyseal profile was deemed to be slight. Displacement approaching the midpoint of the diaphyseal profile was labeled moderate and any displacement greater than this was called severe. Within this classification, two large groups were created: moderate-to-severe, and nil-to slight. The same groupings were established in regard to distribution of the degree of comminution [8, 24]. With respect to wound type, the nil-to-slight group contained the patients who showed no sign of a wound and those with wounds up to about 2 cm in extent; all others were in the moderate-to-severe group. Another simple classification was made to group the open wounds into three types (Table 1). In the study on fracture consolidation, the signs of clinical union were obvious: the periosteal callus joined both fracture fragments, the patients were able to walk without a plaster, and no image of circumferential interfragmentary fissuring exceeded 1/4 of the fracture [18].
54 For analysis of the reliability curves a multivariate analysis was performed based on the Cox regression model. Throughout the study, alternative hypotheses were accepted: H1 as long as the probability level was equal to or less than 0.05 (P--0.05). •
1 ....
13-M Ya
.! I
3-o
i
Fig.1. Levels of fracture of the tibial diaphysis. P, proximal; M, middle; D, distal
Table 1. Wound types: description and classification of open frac-
tures Type Open Type I Type II Type III
Description Gashes and wounds up to 2 cm Wounds of 3-10 cm Wounds longer than 10 cm, with laceration and/or loss of skin
In the analysis, fractures which united within 21 weeks were classified as N (rapid or normal); those that took longer were labeled D (delayed or no Union).
Statistical analysis The results of the study were recorded magnetically for analysis using the BMDP set of programs [13] on a Bull model DPS7 computer. For analysis of the risk factors different tests were employed (comparison of proportions, the Z2 test, etc.) that permitted us to carry out the study from the univariate perspective. The Kaplan and Meier [16] model was used as the method for searching for risk factors, taking "consolidation of the fracture" as the event sought.
Results
T h e m e a n h o s p i t a l stay of the p a t i e n t s was 12.7 days (SD + 14.4 days). O f the p a t i e n t s 68.5% w e r e m a l e a n d 31.5% f e m a l e . M e a n age was 44.6 y e a r s ( S D 20.1 y e a r s ) , a g r e a t e r i n c i d e n c e of fractures a p p e a r i n g in t h e age g r o u p b e t w e e n 45 a n d 60 y e a r s ( 3 0 . 5 % ) , a l t h o u g h this p e r c e n t a g e was v e r y similar to t h a t f o u n d for the 2 1 - 4 4 age g r o u p ( 2 9 . 8 % ) . C a s u a l a c c i d e n t was t h e m o s t f r e q u e n t c a u s a t i v e a g e n t of t h e lesions, o c c u r r i n g in 38.4% o f t h e cases; this was f o l l o w e d b y traffic a c c i d e n t s ( 3 5 . 7 % ) i n d u s t r i a l accid e n t s ( 1 6 . 7 % ) , s p o r t s a c c i d e n t s ( 8 . 3 % ) a n d traffic-occupational accidents (0.9%) T h e c o m m o n e s t fracture was the closed t y p e ( 7 0 . 9 % ) . F r a c t u r e o f t h e t i b i a was a s s o c i a t e d with t h a t o f t h e fibula in 77.3% of cases; in 49 cases t h e tibial f r a c t u r e was a c c o m p a n i e d b y an intact fibula, this figure r e p r e senting 22.7% of cases. O f the f r a c t u r e fibulae, 34.1% h a d c o m m i n u t e d loci. O r t h o p e d i c r e d u c t i o n of t h e f r a c t u r e was c a r r i e d o u t within t h e first 6 h after injury in 82.9% of p a t i e n t s ; in t h e r e m a i n i n g 27.1% r e d u c t i o n was p e r f o r m e d after a m e a n o f 10.5 days. T w e l v e a n d a h a l f p e r c e n t o f the p a t i e n t s w e r e t r e a t e d with an i s c h i o p e d i c p l a s t e r cast with a S t e i n m a n n pin; in t h e r e m a i n i n g 87.5% o n l y an i s c h i o p e d i c p l a s t e r cast was fitted. T r e a t m e n t r e s u l t e d in a m e a n valgus d e v i a t i o n of 4 ° in 45.4% of t h e tibial d i a p h y s e a l f r a c t u r e s a n d a m e a n a n t e c u r v a t u m d e v i a t i o n of 5 ° in 3 7 . 5 % . T h e m o s t c o m m o n r e s i d u a l d e f o r m i t y o b s e r v e d r a d i o l o g i c a l l y was v a r u s , a p p e a r i n g in 44.4% ( m e a n d e v i a t i o n 4°); this was foll o w e d b y r e c u r v a t u m d e f o r m i t y in 40.7% ( m e a n d e v i a tion 4°; T a b l e 2). F r a c t u r e u n i o n was a c h i e v e d within 21 w e e k s in 64.0% o f cases ( T a b l e 3). T h e a p p e a r a n c e o f s e c o n d a r y d i s p l a c e m e n t s within t h e p l a s t e r was o b s e r v e d in 70% o f t h e p a t i e n t s , glypsot o m y b e i n g r e q u i r e d in 16.2% o f these.
Univariate analysis of prognostic factors T a b l e s 4 a n d 5 s h o w t h e results o b t a i n e d in the univari a t e analysis.
Table 2. Fracture deformity
Initial deformity of fracture
Varus
Valgus
Antecurvatum
Recurvatum
Shortening
5° _+ 3°
6°-+ 3° (57.9%) 4°+2 ° (45.4%) 4° + 2° (33.8°/0)
7° + 3° (48.1°/0) 5°+2 ° (37.5%) 5° + 2° (38.4°/0)
5°-+ 3° (33.8%) 4°+2 ° (34.2%) 4° + 2° (40.7%)
8--2 5mm (77.3 % ) 6+3mm (54.6°/0) 8 + 5 mm (74.1%)
(30.1%) Deformity and alignment with treatment Residual deformity (after union)
3° + 1° (28.2%) 4° + 2° (44.4°/0)
55 Table 3. Time required for union of fracture (mean 20 + 7 weeks) Weeks
% of patients
12 13-16 17-21 22-26 27-34 35-48 > 48
2.8 21.8 42.6 20.8 8.3 2.3 1.4
Parameter
Table 4. Results of univariate analysis: prognostic factors Parameter Initial displacement (M-S) N-Union D-Union Degree of comminution (M-S) N-Union D-Union Type of wound (M-S) N-Union D-Union Type of fracture N-Union Open: Type I Type II Type III Closed D-Union Open: Type I Type II Type III Closed Time taken to start to walk (-->6 weeks) N-Union D-Union Post-fracture hematoma present N-Union D-Union Secondary displacement present N-Union D-Union Surface infection of soft tissues present N-Union D-Union Intact fibula N-Union D-Union
Table 5. Univariate analysis: prognostic factors in relation to treatment
Overall series %
P
50.3 74.6
0.0006
Beginning of radiologically detectable callus N-Union D-Union Type of wound N-Union D-Union Degree of comminution (M-S) N-Union D-Union Initial displacement (M-S) N-Union D-Union
IschiopedicSteinmann
P
Ischiopedic
P
10 8
0.05
67 28
0.0001
7 8
0.5
13 12
0.05
7 12
0.01
58 28
0.6
10 13
0.01
64 40
0.OO7
M-S, moderate-to-severe 44.8 55.6
0.6
13.8 28.2
0.01
11.7 10.4 0.7 77.2
0.015
15.5 25.4 1.4 57.7 31.03 53.52
0.0013
0.0 8.45
0.0003
63.4 84.5 0.0 2.81 65.3 34.7
0.001
0.04
-<0.0001
M-S, moderate-to-severe In the fractures treated with the ischiopedic-Steinm a n n method, which were caused by high-energy trauma, there was a significantly higher percentage of Dunions (66.6%, P = 0.04). Location of the focus of the fracture in the fibula led to a significant delay in the union of the fracture (P = 0.04).
Initial interfragmentary displacement at the level of the focus of the tibial fracture and the existence of a fractured fibula were found to be the most significant prognostic factors. Of the 126 fractures classified a moderateto-severe, only 73 tended towards N-union, with significant differences on comparison with the nil-to-slight group (72/90, P = 0.001). This was exactly the same in the fractures treated by the ischiopedic-Steinmann method (P = 0.001). Of the fractures with moderate-to-severe comminution, 65.15% had D-union. Regarding the type of wound, statistically significant differences were observed between the moderate-to-severe and the nil-toslight groups, D-union appearing with greater frequency in the moderate-to-severe group (50.0%, P = 0.01); the same was the case in the fractures immobilized by ischiopedic plaster cast. A m o n g the types of fracture, the closed type showed a greater tendency towards N-union that the others (open types I, II, and III). The subgroup with the greatest tendency towards D-union was type II, which showed statistically significant differences c o m p a r e d with the rest. The results obtained for the appearance of radiological callus (which could not be clearly evidenced in all fractures) showed that the longer the time that the callus took to appear, the m o r e significant became the tendency towards D-union. The effect of weight-bearing on the affected extremity proved to be an important risk factor to be taken into account, since the fractures subjected to weight-bearing within the first 6 weeks tended appreciably towards N-union (110 cases out of 133), by contrast to those cases in which weight-bearing was begun after 6 weeks had elapsed (45 cases out of 83). In the six cases in which post-fracture h e m a t o m a was observed, D-union was very common; of the 152 cases in which secondary displacements were observed, 60 had D-union; two fractures developing a surface infection of the soft tissues had a D-union.
56 Table 6, Multivariate analysis: Cox's continuous regression model Variable
Coefficient
P (Overall)
Initial displacement (D) Secondary displacement (D~) Age (A)
- 0.5574 - 0.4245 - 0.0131
0.0000
Ln = -0.0131 x A - 0.5574 × D - 0.4245 x Ds
Multivariate analysis The most numerous group of patients (treatment with ischiopedic plaster cast) were chosen to construct a predictive model. The variable found to have the greatest predictive value was initial displacement, followed by secondary displacement and age (Table 6). These variables acted by altering the time to union.
Discussion This retrospective study of tibial diaphyseal fractures treated orthopedically and in which a functional plaster cast was fitted for the start of weight-bearing showed that 60% of fractures united within the first 21 weeks after injury. In the cases in which external immobilization was initially carried out with an ischiopedic plaster cast the tendency was towards normal or rapid union. This was not the case in the fractures in which Steinmann pins were used (anterior tuberosity and calcaneus); in these the tendency was towards delayed union or no union at all. It would appear that use of Steinmann pins prevents the necessary mechanical tension at the level of the focus of the fracture required for the development of more normal biological activity [10]. High-energy trauma as the cause of bone fracture has been regarded as a factor of risk which may often lead to a delayed union or no-union; thus, involving risk but still associated with normal or rapid union. However, Bauer et al. (1962) refer to the p o o r results obtained in tibial diaphyseal fractures in high energy traumatisms, and this was also highlighted by Oni et al. (1988). Initial moderate-to-severe interfragmentary displacement occasioned by the traumatic agent has been shown to be a causative factor in delayed or absent union [21]. This was confirmed in our study, although though to a lesser extent the type of wound and/or comminution was also observed to be involved, corroborating the idea [21]. The alterations in the tension model arising from the presence of an intact fibula [30] were not found to be a risk factor in fracture union; however, the location of the fracture of the bone concomitant with tibial fracture was, with accords with the idea of Oni et al. (1988). Closed fractures achieved normal or rapid union with greater frequency than open ones; supporting the notion that in the latter, to a large extent the union depends on "the duration of the infection" [34]. In the fractures in which initiation of a radiologically observable callus appeared within the first 8 weeks after injury, there was a reduced risk of delay or absence of
union. This kind of behaviour was not seen when weightbearing was not initiated in the first 6 weeks; the trend under this circumstance was to prolong the time to union, in agreement with the findings of Heppenstall et al. (1984). The following were also found to be significant for a result of delayed or absent union: post-fracture h e m a t o m a slowing down the reabsorption of necrotic tissue and the differentiation of pluripotential progenitor cells [29]; secondary displacements after reduction, which are intimately related to the amount of fibrocartilage present [24]; and infection of soft tissues. With respect to the patients treated with an ischiopedic plaster cast, our study showed that initial displacement, secondary displacements, and the age of the patient act jointly by altering the time to consolidation of the fracture. Accordingly, in the orthopedic treatment of tibial diaphyseal fractures there seem not only to be factors inherent in the patient and the fracture, but also factors that must be regarded as related to the treatment method employed, that m a y affect the time to union of this eccentric bone of the leg.
References 1. Anderson LD, Hutchins WC, Wright E, Disney JM (1974) Fractures of the tibia and fibula treated by casts and transfixing pins. Clin Orthop 105 : 179-191 2. Bauer GCH, Edwards P, Widmark PH (1962) Shaft fractures of the tibia. Etiology of poor results in a consecutive series of 173 fractures. Acta Chir Scand 124 : 386-395 3. Bohler L (1961) Technica del tratamiento de las fracturas. Labor, Barcelona 4. Bone LD, Johnson KD (1986) Treatment of tibial fractures by reaming and intramedullary nailing. J Bone Joint Surg [Am] 68 : 877-887 5. Bostman OM (1986) Spiral fractures of the shaft of the tibia. Initial displacement and stability of reduction. J Bone Joint Surg [Br] 68 : 462-466 6. Briot B (1983) Rappel des particularit6s de la consolidation des fractures trait~es par les m~thodes orthop6diques. Rev Chir Orthop 69 : 344-346 7. Charnley J (1961) The closed treatment of common fractures. Livingstone, Edinburgh 8. Darder A, Gomar F (1975) A series of tibial fractures treated conservatively. Injury 6 : 225-235 9. Dehne E (1974) Ambulatory treatment of the fractured tibia. Clin Orthop 105 : 192-201 10. Dehne E (1980) The rationale of early functional loading in the healing of fractures: a comprehensive gate control concept of repair. Clin Orthop 146 : 18-27 11. Delbet P (1914) Methode de traitement des fractures. Rev Chir 34: 249-288 12. DeLee JC (1979) Ipsilateral fracture of the femur and tibia treated in a quadrilateral cast brace. Clin Orthop 142:115-122 13. Dixon WI (1985) BMDP statistical software. University of California Press, Berkeley 14. Goodship AE, Kenwright (1985) The influence of induced microvement upon the healing of experimental final fractures. J Bone Joint Surg [Br] 67: 650-655 15. Heppenstall RB, Brighton CT, Esterhai JL Jr, Muller G (1984) Prognostic factors in nonunion of the tibia: an evaluation of 185 cases treated with constant direct current. J Trauma 24: 790-795 16. Kaplan EL, Meier P (1958) Nonparametric estimation from incomplete observations. J Am Stat Assoc 53 : 457 17. McLaughlin HL (1961) Trauma. Interamericana, Mexico
57 18. Merianos P, Cambouridis P, Smyrnis P (1985) The treatment of 143 tibila shaft fractures by Ender's nailing and early weightbearing. J Bone Joint Surg [Br] 67 : 576-580 19. Mooney V (1974) Cast bracing. Clin Orthop 102 : 159-166 20. Moyen B, Comtet JJ (1983) Consolidation des fractures des os longs. Aspects biologiques. Rev Chir Orthop 69 : 341-343 21. Nicoll E A (1964) Fractures of the tibial shaft. A survey of 705 cases. J Bone Joint Surg [Br] 46 : 373-387 22. Nicoll E A (1974) Closed and open management of tibial fractures. Clin Orthop 105 : 144-153 23. Oni OOA, Hui A, Gregg PJ (1988) The healing of closed tibial shaft fractures. The natural history of union with closed treatment. J Bone Joint Surg [Br] 70 : 787-790 24. Rhinelander FW (1974) Tibial blood supply in relation to fracture healing. Clin Orthop 105 : 34-81 25. Rodriguez L (1982) La membrana interosea en las fracturas de la pierna. Estudio experimental y clinico. Doctoral thesis, University of Salamanca 26. Sarmiento A (1974) Fracture bracing. Clin Orthop 102:152158 27. Sarmiento A, Latta LL (1982) Tratamiento functional incruento de las fracturas. M~dica Panamericana, Buenos Aires
28. Sarmiento A, Latta LL, Zilioli A, Sinclaire W (1974) The role of soft tissues in the stabilization of tibial fractures. Clin Orthop 105 : 116-129 29. Simmons DJ (1985) Fracture healing perspectives. Clin Orthop 200 : 100-113 30. Teitz CC, Carter DR, Frankel VH (1980) Problems associated with tibial fracture with intact fibulae. J Bone Joint Surg [Am] 62 : 770-776 31. Uhthoff HK, Finnegan MA (1983) L'influence du degrd de la rigidit~ sur la mobilit~ interfragmentaire et la ddformation osseuse. Rev Chir Orthop 69 : 346-347 32. Waddell JP, Reardon GP (1983) Complications of tibial shaft fractures. Clin Orthop 178 : 173-178 33. Watson-Jones R (1957) Fracturas y traumatismos articulares. Salvat, Barcelona 34. Watson-Jones R (1974) The classic. Fractures and joint injuries. Clin Orthop 105 : 4-10 35. Watson-Jones R, Coltart WD (1982) The classic. Slow union of fractures: with a study of 804 fractures of the shafts of the tibia and femur. Clin Orthop 168 : 2-16