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Dorsal plating of unstable distal radius fractures using a bio-absorbable plating system and bone substitute
ARTICLE IN PRESS DORSAL PLATING OF UNSTABLE DISTAL RADIUS FRACTURES USING A BIO-ABSORBABLE PLATING SYSTEM AND BONE SUBSTITUTE S. GANGOPADHYAY, K. RAVI and G. PACKER From the Southend Hospital, Westcliff-on-Sea, Essex, UK
This study reports the results of open reduction and internal fixation of 26 unstable, intraarticular, dorsally displaced fractures of the distal radius using a bio-absorbable dorsal distal radius (Reunite) plate and calcium phosphate (Biobon) bone substitute. The bio-absorbable plate has the advantage of being low profile, easily contourable and angularly stable. In the majority of cases, this plate produces functional results comparable with metal plates. The Gartland and Werley score was excellent or good in 21 patients. The theoretical advantage over metal plates is in eliminating the need to remove the plate and hence the need for a second operation if implant-related extensor tenosynovitis occurs. Inflammatory tissue reaction to the degradation products of the plate is a potential concern, although the co-polymer ratio used in this plate appears to have reduced the severity of this reaction, which was seen in two patients in this series. The reduction was lost in five patients with severe dorsal comminution. Following this experience, we do not recommend this plating system for fractures with a metaphyseal gap of greater than 7 mm following reduction. Journal of Hand Surgery (British and European Volume, 2006) 31B: 1: 93–100 Keywords: fracture, distal radius, bio-absorbable, dorsal comminution, bone substitute
This paper reports the results of treatment of unstable distal radius fractures using a bio absorbable, dorsal distal radius plate (Reunite; Biomet Inc., Warsaw, IN) (Fig 1) and calcium phosphate bone substitute in 26 patients.
INTRODUCTION Many studies have shown that dorsal plating is an effective method of fixation of unstable distal radius fractures (Campbell, 2000; Carter et al., 1998; Fitoussi et al., 1997; Jakob et al., 2000; Ring et al., 1997). However, complication rates as high as 50% have been reported (Axelrod and McMurtry, 1990). In this series, 29% of the patients developed extensor tenosynovitis, which required plate removal and tenolysis. Attempts to address this problem have involved the use of a lowprofile, pre-shaped, rigid, stainless-steel plate (Carter et al., 1998), a low-profile, contourable, titanium, dorsal distal radius plate (Ring et al., 1997) and a 2.0 mm, lowprofile, titanium plate (Jakob et al., 2000; Rikli and Regazzoni, 1996). However, in these studies, between 12% and 23% of patients still required removal of the plate (Campbell, 2000; Carter et al., 1998; Jakob et al., 2000; Ring et al., 1997). Difficulty in contouring and trimming of the plate and adapting it to the pathological anatomy of the fractured distal radius is another problem. The ideal plate should have a low profile, be easily contourable to the pathological and, often, variable anatomy of the fracture, be easily cut to the required length without leaving sharp edges and provide angular stability, when required. The contourable, titanium, Pi plate addresses this issue, but tendon ruptures on the cut edge of these plates have been reported (Jakob et al., 2000). A plate which reabsorbed following fracture healing, thereby making implant removal because of persistent tendon irritation less likely, would complete this wish list for the ideal plate.
PATIENTS AND METHODS Twenty-eight consecutive patients with isolated, unilateral, dorsally displaced or angulated, unstable distal radius fractures were treated by open reduction and internal fixation using the Reunite bio absorbable distal radius plating system and calcium phosphate bone substitute between March 2001 and May 2003. Two patients were lost to follow-up and a total of 26 patients were available for review. The mean age at injury was 53 (range 17–87) years. This series included ten men and 16 women. Fourteen were right-hand dominant. Twenty-two fell on their outstretched hands, two fell from a height and two were injured playing football. All fractures were dorsally displaced, dorsally angulated or both (Fig 2a). There were 15 Frykman VIII, 9 Frykman VII and 2 Frykman VI fractures (Frykman, 1967). All operations were performed by the senior author. The plate The bio absorbable dorsal distal radius plate is a copolymer of l lactic acid and glycolic acid. It is a 2.5 mm plate, available in small and large sizes. A special 93
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Fig 1 The Reunite bio-absorbable dorsal distal radius plate.
heat pack is activated and the plate is placed in the heat pack to render it malleable by raising the temperature of the polymer above the glass transition temperature (55–60 1C). Surgical technique Following general, or regional, anaesthesia and application of a tourniquet, the arm was placed on a radiolucent arm table. The skin was incised using a dorsal ‘‘T’’ incision (Dao et al., 2000) to expose the wrist between the third and fourth extensor compartments. The extensor tendons were retracted and a subperiosteal dissection used to expose the distal radius. Lister’s tubercle was usually fragmented. If so, these fragments were removed. If possible, depending on the degree of comminution, the extensor pollicis longus (EPL) was elevated while retaining it within its sheath,
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so that it could be re-attached later. The posterior interosseous nerve, when encountered, was resected to avoid it being irritated by the plate. The dorsal comminution of the fracture was explored and the fracture reduced by a combination of traction and leverage. K-wires were used to maintain the reduced position, which was checked using the image intensifier (Fig 2b). After heating, the malleable plate was applied directly to the dorsal surface of the distal radius with pressure and moulded to the anatomy of the reduced fracture site. This temporary malleability allows accurate contouring of the plate to the shape of the distal radius. Most commonly, a small plate was used. If required, the malleable plate can be cut with scissors to a suitable shape and size, although we rarely found this necessary. Adequate exposure of the distal radius is very important, as the malleable plate must be applied directly to the bony surface. It cannot be slid under soft tissues, because it lacks the firmness of metal plates while in the malleable state. Once satisfactory moulding had taken place and the plate had hardened, it was fixed to the distal radius using bio-absorbable screws, which were inserted using a 2.2 mm drill and a 2.5 mm tap. In order to provide angular stability, a cautery pen was used to ‘‘spot weld’’ the screw heads to the plate. Although more important at the articular surface, this was done as a routine along the plate, as it serves to mould the screw heads, further lowering their profile. Once sufficient number of screws had been inserted, usually four distally and four proximally, the metaphyseal defect (dorsal comminution) was filled with calcium phosphate bone substitute (Biobon; Merck Biomaterial GmbH, Darmstadt, Germany). Biobon is presented in powder form and is reconstituted with normal saline to form an injectable paste that solidifies at body temperature. This injectable form was introduced into the metaphyseal defect using a syringe and wide bore needle through one of the overlying empty screw holes. A final intraoperative radiograph was taken prior to closure (Fig 2c). The periosteal layer was closed such that the plate was not in direct contact with the extensor tendons, taking care to recreate a sling for the EPL. When severe comminution prevented periosteal closure, a flap of the extensor retinaculum was fashioned and interposed between the plate and the tendons. The skin was closed using absorbable sutures and a wool and crepe bandage applied. Postoperatively, the arm was elevated and supervised physiotherapy commenced on the first postoperative day. No restrictions were imposed on the intensity of physiotherapy and range of movement exercises were
Fig 2 (a) Pre-operative radiographs of a Frykman VII fracture. (b) Intraoperative radiograph of the same fracture following open reduction and temporary fixation with a K-wire. Note the metaphyseal gap following reduction. (c) Final intraoperative radiograph of the same fracture. Note the screw holes indicating the position of the plate and the metaphyseal gap filled with Biobon. (d) Radiographs of the same fracture at 6 weeks. The fracture line is still visible and the metaphyseal gap remains filled with Biobon. (e) Radiographs of the same fracture at 1 year. The fracture has healed and the Biobon has been replaced by bone.
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commenced immediately. A removable wrist splint was worn intermittently between periods of mobilization for the first 2 weeks. The splint was discontinued once the soft tissues had healed. The patients were assessed through personal interview by two assessors other than the surgeon. Residual pain was assessed using the visual analogue scale. The subjective and objective results were assessed using the modification of Gartland and Werley’s (1951) demerit point system described by Sarmiento et al. (1975), which is commonly used to assess outcome of management of wrist fractures. The range of movement of the wrist was measured using a goniometer, finger flexion was measured as the distance between the tips of the fingers and the distal palmar crease on maximum active finger flexion. Grip strength was measured using a Jamar dynamometer, recording the best of three readings at setting 2. Radiographs taken at the time of injury were used to obtain the Frykman classification of each fracture (Frykman, 1967) (Fig 2a). Radiographs taken at the time of surgery, at 6 and 12 weeks and at the time of this review were compared (Figs 2c–e). The intraoperative radiographs and the radiographs taken at the time of this review were standardized for the position of the shoulder and elbow and only these two X-rays were used for the final comparison of maintenance of reduction. All the X-rays were digital images so comparative assessment of radial length could be accurately done using the digital scale. Radial length was measured along the ulnar margin with reference to the most distal aspect of the ulnar head (Kreder et al., 1996). Radial and palmar inclinations were measured according to the system described by Gartland and Werley (1951). We defined a satisfactory reduction as a loss of less than 101 of palmar tilt (i.e. no dorsal angulation beyond neutral), less than 2 mm of radial length (i.e. radial articular surface no shorter than the ulnar articular surface at the Table 1—Pain score (visual analogue scale) Pain score
No. of patients
0 1 2 3 4 5 6 7 or more
13 1 6 2 1 2 1 0
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level of the radiocarpal joint) and less than 1 mm of joint incongruity. We accepted 161 of radial inclination as satisfactory.
RESULTS A total of 26 patients were available for review. The length of follow-up was 17 (range 7–31) months. Thirteen patients had a pain score of zero (Table 1). The median pain score was 0.5 (range 0–6). One patient who had plate failure with complete loss of reduction at 6 weeks had a pain score of 4. One patient with a pain score of 5 had lost radial length at 12 weeks and required an ulna matching procedure. The other patient with a pain score of 5 had an acceptable radiological result and no other clinical complications to explain the persistent pain. The patient with a pain score of 6 had lost radial length and palmar inclination at 12 weeks, but refused further surgery. The Gartland and Werley score was excellent or good in 21 patients, fair in three and poor in two. Two patients with fair results and one with a poor result had lost the reduction achieved at the time of surgery by 12 weeks. One patient with a fair result had persistent pain without any clinical complications or radiological evidence of malunion. The remaining patient with a poor result had persistent dorsal angulation at the end of the initial operation and sustained a rupture of the extensor digitorum communis tendon to the middle finger at 20 weeks. The range of movements of the injured and normal wrists are shown in Table 2. Tethering of the finger extensors and resultant loss of flexion is a potential complication following any wrist pathology and dorsal intervention. We did not encounter this problem at any stage of the follow-up and, at final review, all patients could flex their fingers to reach the distal palmar crease. The mean grip strength was 70% of the uninjured side, measuring 22 (range 3–50) kg on the injured side and 31 (range 8–52) kg on the uninjured side. Based on the radiological criteria defined above, satisfactory reduction was achieved at surgery in 22 of the 26 patients. Two patients had articular steps greater than 1 mm, one patient had 2 mm of radial shortening and one patient had a persistent dorsal angulation of 51 beyond neutral. All these patients with less than satisfactory initial reductions maintained the positions achieved at surgery throughout the period of follow-up.
Table 2—Mean ranges of movement in degrees (range) of the injured and normal wrists
Injured Normal
Dorsiflexion
Palmarflexion
Ulnar deviation
Radial deviation
Supination
Pronation
45 (21–48) 55 (20–80)
54 (42–63) 71 (54–95)
29 (17–34) 39 (20–55)
14 (8–18) 16 (5–23)
82 (84–90) 87 (70–95)
86 (86–90) 88 (75–90)
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Five patients had lost the reduction achieved at surgery. In one, the reduction was lost at 6 weeks and, in the remaining four, between 6 and 12 weeks. All these patients had severe dorsal comminution resulting in a substantial metaphyseal gap following restoration of length and inclination. The metaphyseal gap measured on the intraoperative radiograph was 8 mm (range 6–11 mm). Three patients had lost radial length (3 mm, 3 mm, 5 mm, respectively) and two patients had lost both radial length and palmar inclination (2 mm, 61 beyond neutral and 5 mm, 141 beyond neutral, respectively). There was one plate failure with complete loss of reduction evident at 6 weeks. The bio-absorbable plate was found to be broken at the time of revision with a stainless-steel, low-profile plate and iliac crest bone graft. In this patient, the eventual functional result was good. Two patients with radial shortening required ulnar matching procedures to restore pain free forearm rotation. The eventual functional score was good. Complications One patient developed a wound infection, which was superficial and resolved with oral antibiotics. Extensor tenosynovitis occurred between 4 and 12 weeks following surgery in two patients and responded within 2 weeks to antiinflammatory medication and temporary splintage. There was one ruptured EPL tendon, which was repaired directly, and one middle finger extensor digitorum communis tendon rupture, which was treated by extensor indices transfer. There were two cases of inflammatory reaction associated with plate resorption, which occurred between 8 and 11 weeks after surgery. One presented with painful swelling and erythema overlying the plate. This was treated by aspiration and the reaction resolved gradually over the next 6 weeks. The final result was excellent. The other, more severe, reaction started as a papule with surrounding erythema. The papule spontaneously ruptured to produce a sinus tract with discharge of fragments of the plate. This patient was taken to theatre for formal debridement. There was florid synovitis with fragments of plate interposed within the soft tissues. The histology reported a non-specific granulomatous reaction. Following debridement, the inflammatory reaction settled over the next 4 weeks and the eventual functional result at final review was excellent.
DISCUSSION The Reunite, bio-absorbable, dorsal distal radius plate is composed of 82% polymerized l lactic acid and 18% polymerized glycolic acid. Manufacturers’ bench test data comparing this material with equivalent metal plates subjected to flex and tensile tests have demonstrated equal, or greater, peak loads up to 6 weeks
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(Sarver, 1995). After this time, the slope of the stress–strain curve increases due to increasing brittleness. In vivo testing, in canine models, has shown that this material retains its strength for 6 to 8 weeks and complete mass loss occurs at 1 year (An et al., 1998). This allows gradual load transfer to the healing bone and obviates the need to remove retained implants for mechanical problems. Another advantage is the radiolucency of the plates and screws, which is said to facilitate postoperative radiographic evaluation. However, this can give rise to difficulties when applying the plate and screws, as it is not possible, using intraoperative imaging, to detect screws that are too close to the articular surface, or too long. All the fractures treated in this series were potentially unstable and, therefore, had metaphyseal defects as a result of dorsal comminution. It is our practice to address metaphyseal defects using either bone graft or bone substitute, irrespective of the method of internal fixation, and, as such, we have no experience of using the plate alone without bone substitute. Autologous bone graft is most commonly used for filling voids in fracture surgery and it remains the gold standard among graft materials. It has the advantage of being osteoinductive and osteoconductive. It stimulates healing and is incorporated into the host bone. However, there is significant morbidity associated with autologous grafting (Ladd and Pliam, 2001). There is an increase in operative time, blood loss, postoperative pain, length of hospital stay and cost. Infection and fractures at the donor site are other possible complications. Bone substitutes have, therefore, emerged as an alternative to improve the outcome. Biobon is composed of calcium phosphate. Reconstitution using normal saline induces a hydraulic curing process that results in a microcrystalline hydroxyapatitic paste that hardens endothermically at body temperature (37 1C). There is evidence that calcium phosphate bone substitute (Norian SRS; Norian, Cupertino, California) improves outcome of distal radius fractures (Cassidy et al., 2003; Kopylov et al., 1996). The clinical effectiveness of Biobon has been reported in the German literature in a study of 29 patients with an average follow-up of 18 months (Linhart et al., 2003). Unstable distal radius fractures were treated with Biobon and additional osteosynthesis. The average outcome using the Gartland and Werley (1951) score was 7.5 (range 2–21) points, representing a good result. These authors concluded that Biobon was a good alternative to autologous bone graft, especially in elderly patients. The range of movement, grip strength and Gartland and Werley scores achieved in this series are comparable with that of similar studies involving dorsal plating of intraarticular distal radius fractures using low-profile metal plates and autologous bone graft where necessary (Tables 3 and 4). The major advantage was avoidance of a second operation for plate removal, the incidence of which varies between 12% and 29% in the literature (Axelrod and McMurtry, 1990; Campbell, 2000; Carter
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et al., 1998; Jakob et al., 2000; Ring et al., 1997). Reoperation leads to further scarring with contracture of the dorsal capsule and extensor sheath with the potential to produce further stiffness. In this series, we had two reoperations for problems relating to malfunction of the implant, which compares favourably with the reoperation rates associated with metal plates as mentioned above. One re-operation was to revise a broken plate at 6 weeks in a fracture with severe dorsal comminution and the other was for exploration and debridement of the inflammatory reaction associated with plate resorption at 11 weeks. Extensor tenosynovitis and tendon ruptures are well documented complications following dorsal plating of distal radius fractures (Table 5). Tendons rupture as a result of a combination of mechanical attrition and devascularisation (Kozin and Wood, 1993). EPL ruptures can occur in association with undisplaced fractures. This tendon has a relatively avascular area adjacent to Lister’s tubercle. Fracture comminution, oedema, haematoma or osseous pressure can compro-
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mise the blood supply further, leading to ischaemic rupture. Attrition ruptures occur as a result of tendon fraying over callus, malunited fragments or prominent implants used for fixation. In this series, the single EPL rupture was of the typical part of the tendon, adjacent to Lister’s tubercle. At exploration, neither of the two ruptured tendons had the frayed appearance of an attrition rupture. There was evidence of synovitis around the tendons and we believe that the ruptures were due a combination of relative ischaemia and inflammatory pathology, as seen in rheumatoid patients. Five patients lost the reduction achieved at surgery. As the loss of reduction occurred between 6 and 12 weeks postoperatively and as the plate retains its strength for 8 weeks, it appears logical that for wrists with severe dorsal comminution, the bio-absorbable plate did not retain its strength for long enough to allow adequate fracture healing for load transfer. Indeed, in a similar series of fractures, with similar follow-up, treated with low-profile titanium plates, 36% of the fractures
Table 3—Gartland and Werley scores compared with other studies Campbell (2000)
Carter et al. (1998)
Jakob et al. (2000)
Ring et al. (1997)
This study
No. of patients Follow-up (months)
25 16
73 18.5
74 12
22 14
26 16.6
Gartland and Werley score (no. of patients) Excellent Good Fair Poor
4 11 10 0
59 10 4 0
62 10 2 0
6 7 9 0
15 6 3 2
Table 4—Mean range of movement (degrees) and grip strength (% of uninjured side) compared with other studies Campbell (2000)
Carter et al. (1998)
Ring et al. (1997)
This study
60 40 — — 90 90 76
58 52 31 20 82 82 87
45 40 21 14 65 76 56
45 54 29 14 82 86 70
Dorsiflexion Palmer flexion Ulnar deviation Radial deviation Supination Pronation Grip strength
Table 5—Extensor tendon related complications following dorsal plating of the distal radius
No. of patients Tenosynovitis Tendon rupture
Campbell (2000)
Carter et al. (1998)
Jakob et al. (2000)
Ring et al. (1997)
This study
25 3 1
73 8 0
74 3 5
22 5 0
26 2 2
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united at 3 months and all united at 6 months (Campbell, 2000). All these patients had severe dorsal comminution resulting in a substantial metaphyseal gap following restoration of length and inclination. By contrast, the four patients with less than satisfactory initial reduction did not lose the position achieved, as the postreduction metaphyseal gap in these fractures was not large enough to prevent healing before loss of strength of the plate. Possible solutions to this problem are to use a plate that will retain its strength for longer for more comminuted fractures or to accelerate the rate of healing by using osteoinductive material, such as cancellous bone graft, to fill the metaphyseal gap. Following this experience, we continue to use the bio-absorbable plate with calcium phosphate bone substitute for unstable intraarticular distal radius fractures that are not suitable for non-operative management (Bartosh and Saldana, 1990) because of articular incongruity or dorsal comminution, provided the metaphyseal gap following reduction does not exceed 7 mm. We use metal plates, with calcium phosphate bone substitute, for treating fractures with severe dorsal comminution with a metaphyseal gap of greater than 7 mm following reduction and additional cancellous bone graft when the metaphyseal gap is greater than 10 mm. The reported complications of bio-absorbable implants include painful erythema, sterile sinus track formation, hypertrophic fibrous encapsulation and, in severe cases, osteolysis (Ciccone et al., 2001). Bo¨stman and Pihlajama¨ki (2000), in a review of 2528 patients treated with bio-absorbable implants, reported an overall incidence of 4% of clinically significant, local inflammatory, sterile tissue reaction. This was reported, histologically, as a non-specific, foreign body reaction. This inflammatory reaction is due to the biological response to the degradation products of the bioabsorbable implants. This degradation follows a specific pattern (Ciccone et al., 2001). There is, initially, a loss of molecular weight, followed by loss of strength and, finally, a loss of mass. The initial phase of degradation is chemical, followed by a biological processing and implant removal that is responsible for the inflammatory response. The most symptomatic reactions have been associated with the more rapidly degrading polymerized glycolic acid. The incidence is 5.3%, as compared to 0.2% with polymerized l lactic acid. Polymerized l lactic acid has been associated with delayed reactions as late as 4.3 years after surgery (Bo¨stman and Pihlajama¨ki, 1998). The rate of degradation and, hence, the inflammatory response can be modulated by altering the proportions of the constituent polymers. The co-polymer ratio in the Reunite bioabsorbable dorsal distal radius plate appears to have reduced the risk of reaction. The two cases of inflammatory reaction in our series occurred at 8 and 11 weeks following surgery. As the plate undergoes
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complete mass loss in 12 months, the risk of a late reaction after that time is unlikely. Nineteen patients in our series had a follow-up of greater than 12 months. We have not had any complaint to date from the remaining patients. Hopefully, further development of the bio-absorbable plates will make them more universally applicable for treating a greater part of the spectrum of unstable distal radius fractures, by increase of the length of time for which they retain their strength, while maintaining the current low incidence of inflammatory complications. References Axelrod TS, McMurtry RY (1990). Open reduction and internal fixation of comminuted, intraarticular fractures of the distal radius. Journal of Hand Surgery, 15A: 1–11. An YH, Friedman RJ, Powers DL, Draughn RA, Latour Jr. RA (1998). Fixation of osteotomies using bioabsorbable screws in the canine femur. Clinical Orthopaedics and Related Research, 355: 300–311. Bartosh RA, Saldana MJ (1990). Intraarticular fractures of the distal radius: a cadaveric study to determine if ligamentotaxis restores radiopalmar tilt. Journal of Hand Surgery, 15A: 18–21. Bo¨stman OM, Pihlajama¨ki HK (1998). Late foreign-body reaction to an intraosseous bioabsorbable polylactic acid screw: a case report. Journal of Bone and Joint Surgery, 80A: 1791–1794. Bo¨stman OM, Pihlajama¨ki HK (2000). Adverse tissue reactions to bioabsorbable fixation devices. Clinical Orthopaedics and Related Research, 371: 216–227. Campbell DA (2000). Open reduction and internal fixation of intra articular and unstable fractures of the distal radius using the AO distal radius plate. Journal of Hand Surgery, 25B: 528–534. Carter PR, Frederick HA, Laseter GF (1998). Open reduction and internal fixation of unstable distal radius fractures with a lowprofile plate: a multicenter study of 73 fractures. Journal of Hand Surgery, 23A: 300–307. Cassidy C, Jupiter JB, Cohen M, Delli-Santi M, Fennell C, Leinberry C, Husband J, Ladd A, Seitz WR, Constanz B (2003). Norian SRS cement compared with conventional fixation in distal radius fractures: a randomized study. Journal of Bone and Joint Surgery, 85A: 2127–2137. Ciccone WJ II, Motz C, Bentley C, Tasto JP (2001). Bioabsorbable implants in orthopaedics: new developments and clinical applications. Journal of the American Academy of Orthopaedic Surgeons, 9: 280–288. Dao KD, Shin AY, Berger RA (2000). T incision for exposure of the distal radius and wrist. Journal of Hand Surgery, 25B: 544–547. Fitoussi F, Ip WY, Chow SP (1997). Treatment of displaced intraarticular fractures of the distal end of the radius with plates. Journal of Bone and Joint Surgery, 79A: 1303–1312. Frykman G (1967). Fracture of the distal radius including sequelae – shoulder–hand–finger syndrome, disturbance in the distal radioulnar joint and impairment of nerve function. A clinical and experimental study. Acta Orthopaedica Scandinavica, Supplementum: 108. Gartland Jr JJ, Werley CW (1951). Evaluation of healed Colles’ fractures. Journal of Bone and Joint Surgery, 33A: 895–906. Jakob M, Rikli DA, Regazzoni P (2000). Fractures of the distal radius treated by internal fixation and early function: a prospective study of 73 consecutive patients. Journal of Bone and Joint Surgery, 82B: 340–344. Kopylov P, Jonsson K, Thorngren KG, Aspenberg P (1996). Injectable calcium phosphate in the treatment of distal radial fractures. Journal of Hand Surgery, 21B: 768–771.
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Kozin SH, Wood MB (1993). Early soft-tissue complications after fractures of the distal part of the radius. Journal of Bone and Joint Surgery, 75A: 144–153. Kreder HJ, Hanel DP, McKee M, Jupiter J, McGillivary G, Swiontkowski MF (1996). X-ray film measurements of healed distal radius fractures. Journal of Hand Surgery, 21A: 31–39. Ladd AL, Pliam NB (2001). The role of bone graft and alternatives in unstable distal radius fracture treatment. Orthopaedic Clinics of North America, 30: 337–351. Linhart W, Briem D, Schmitz ND, Priemel M, Lehmann W, Rueger JM (2003). Treatment of metaphyseal bone defects after fractures of the distal radius. Medium-term results using calcium-phosphate cement (BIOBON). Unfallchirurg, 106: 618–624. Rikli DA, Regazzoni P (1996). Fractures of the distal end of the radius treated by internal fixation and early function: a preliminary report of 20 cases. Journal of Bone and Joint Surgery, 78B: 588–592. Ring D, Jupiter JB, Boston, Brennwald J, Bu¨chler U, Hastings H (1997). Prospective multicenter trial of a plate for dorsal
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fixation of distal radius fractures. Journal of Hand Surgery, 22A: 777–784. Sarmiento A, Pratt GW, Berry NC, Sinclair WF (1975). Colles’ fractures: functional bracing in supination. Journal of Bone and Joint Surgery, 57A: 311–317. Sarver D. Mechanical testing of the Lactosorb 2 mm trauma plates in comparison with metallic fixation. Warsaw, IN, Biomet Inc., 1995. Received: 7 October 2004 Accepted after revision: 15 September 2005 No funding or benefits in any form have been or will be received by any of the authors from any of the commercial parties related to the subject of this paper. Mr S. Gangopadhyay, 108 Abbey Road, West Bridgford, Nottingham NG2 5NB, UK. Tel.: +441159235029; fax: +441702221088. E-mail: [email protected]
r 2005 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2005.09.015 available online at http://www.sciencedirect.com
This study reports the results of open reduction and internal fixation of 26 unstable, intraarticular, dorsally displaced fractures of the distal radius using a bio-absorbable dorsal distal radius (Reunite) plate and calcium phosphate (Biobon) bone substitute. The bio-absorbable plate has the advantage of being low profile, easily contourable and angularly stable. In the majority of cases, this plate produces functional results comparable with metal plates. The Gartland and Werley score was excellent or good in 21 patients. The theoretical advantage over metal plates is in eliminating the need to remove the plate and hence the need for a second operation if implant-related extensor tenosynovitis occurs. Inflammatory tissue reaction to the degradation products of the plate is a potential concern, although the co-polymer ratio used in this plate appears to have reduced the severity of this reaction, which was seen in two patients in this series. The reduction was lost in five patients with severe dorsal comminution. Following this experience, we do not recommend this plating system for fractures with a metaphyseal gap of greater than 7 mm following reduction. Journal of Hand Surgery (British and European Volume, 2006) 31B: 1: 93–100 Keywords: fracture, distal radius, bio-absorbable, dorsal comminution, bone substitute
This paper reports the results of treatment of unstable distal radius fractures using a bio absorbable, dorsal distal radius plate (Reunite; Biomet Inc., Warsaw, IN) (Fig 1) and calcium phosphate bone substitute in 26 patients.
INTRODUCTION Many studies have shown that dorsal plating is an effective method of fixation of unstable distal radius fractures (Campbell, 2000; Carter et al., 1998; Fitoussi et al., 1997; Jakob et al., 2000; Ring et al., 1997). However, complication rates as high as 50% have been reported (Axelrod and McMurtry, 1990). In this series, 29% of the patients developed extensor tenosynovitis, which required plate removal and tenolysis. Attempts to address this problem have involved the use of a lowprofile, pre-shaped, rigid, stainless-steel plate (Carter et al., 1998), a low-profile, contourable, titanium, dorsal distal radius plate (Ring et al., 1997) and a 2.0 mm, lowprofile, titanium plate (Jakob et al., 2000; Rikli and Regazzoni, 1996). However, in these studies, between 12% and 23% of patients still required removal of the plate (Campbell, 2000; Carter et al., 1998; Jakob et al., 2000; Ring et al., 1997). Difficulty in contouring and trimming of the plate and adapting it to the pathological anatomy of the fractured distal radius is another problem. The ideal plate should have a low profile, be easily contourable to the pathological and, often, variable anatomy of the fracture, be easily cut to the required length without leaving sharp edges and provide angular stability, when required. The contourable, titanium, Pi plate addresses this issue, but tendon ruptures on the cut edge of these plates have been reported (Jakob et al., 2000). A plate which reabsorbed following fracture healing, thereby making implant removal because of persistent tendon irritation less likely, would complete this wish list for the ideal plate.
PATIENTS AND METHODS Twenty-eight consecutive patients with isolated, unilateral, dorsally displaced or angulated, unstable distal radius fractures were treated by open reduction and internal fixation using the Reunite bio absorbable distal radius plating system and calcium phosphate bone substitute between March 2001 and May 2003. Two patients were lost to follow-up and a total of 26 patients were available for review. The mean age at injury was 53 (range 17–87) years. This series included ten men and 16 women. Fourteen were right-hand dominant. Twenty-two fell on their outstretched hands, two fell from a height and two were injured playing football. All fractures were dorsally displaced, dorsally angulated or both (Fig 2a). There were 15 Frykman VIII, 9 Frykman VII and 2 Frykman VI fractures (Frykman, 1967). All operations were performed by the senior author. The plate The bio absorbable dorsal distal radius plate is a copolymer of l lactic acid and glycolic acid. It is a 2.5 mm plate, available in small and large sizes. A special 93
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Fig 1 The Reunite bio-absorbable dorsal distal radius plate.
heat pack is activated and the plate is placed in the heat pack to render it malleable by raising the temperature of the polymer above the glass transition temperature (55–60 1C). Surgical technique Following general, or regional, anaesthesia and application of a tourniquet, the arm was placed on a radiolucent arm table. The skin was incised using a dorsal ‘‘T’’ incision (Dao et al., 2000) to expose the wrist between the third and fourth extensor compartments. The extensor tendons were retracted and a subperiosteal dissection used to expose the distal radius. Lister’s tubercle was usually fragmented. If so, these fragments were removed. If possible, depending on the degree of comminution, the extensor pollicis longus (EPL) was elevated while retaining it within its sheath,
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so that it could be re-attached later. The posterior interosseous nerve, when encountered, was resected to avoid it being irritated by the plate. The dorsal comminution of the fracture was explored and the fracture reduced by a combination of traction and leverage. K-wires were used to maintain the reduced position, which was checked using the image intensifier (Fig 2b). After heating, the malleable plate was applied directly to the dorsal surface of the distal radius with pressure and moulded to the anatomy of the reduced fracture site. This temporary malleability allows accurate contouring of the plate to the shape of the distal radius. Most commonly, a small plate was used. If required, the malleable plate can be cut with scissors to a suitable shape and size, although we rarely found this necessary. Adequate exposure of the distal radius is very important, as the malleable plate must be applied directly to the bony surface. It cannot be slid under soft tissues, because it lacks the firmness of metal plates while in the malleable state. Once satisfactory moulding had taken place and the plate had hardened, it was fixed to the distal radius using bio-absorbable screws, which were inserted using a 2.2 mm drill and a 2.5 mm tap. In order to provide angular stability, a cautery pen was used to ‘‘spot weld’’ the screw heads to the plate. Although more important at the articular surface, this was done as a routine along the plate, as it serves to mould the screw heads, further lowering their profile. Once sufficient number of screws had been inserted, usually four distally and four proximally, the metaphyseal defect (dorsal comminution) was filled with calcium phosphate bone substitute (Biobon; Merck Biomaterial GmbH, Darmstadt, Germany). Biobon is presented in powder form and is reconstituted with normal saline to form an injectable paste that solidifies at body temperature. This injectable form was introduced into the metaphyseal defect using a syringe and wide bore needle through one of the overlying empty screw holes. A final intraoperative radiograph was taken prior to closure (Fig 2c). The periosteal layer was closed such that the plate was not in direct contact with the extensor tendons, taking care to recreate a sling for the EPL. When severe comminution prevented periosteal closure, a flap of the extensor retinaculum was fashioned and interposed between the plate and the tendons. The skin was closed using absorbable sutures and a wool and crepe bandage applied. Postoperatively, the arm was elevated and supervised physiotherapy commenced on the first postoperative day. No restrictions were imposed on the intensity of physiotherapy and range of movement exercises were
Fig 2 (a) Pre-operative radiographs of a Frykman VII fracture. (b) Intraoperative radiograph of the same fracture following open reduction and temporary fixation with a K-wire. Note the metaphyseal gap following reduction. (c) Final intraoperative radiograph of the same fracture. Note the screw holes indicating the position of the plate and the metaphyseal gap filled with Biobon. (d) Radiographs of the same fracture at 6 weeks. The fracture line is still visible and the metaphyseal gap remains filled with Biobon. (e) Radiographs of the same fracture at 1 year. The fracture has healed and the Biobon has been replaced by bone.
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commenced immediately. A removable wrist splint was worn intermittently between periods of mobilization for the first 2 weeks. The splint was discontinued once the soft tissues had healed. The patients were assessed through personal interview by two assessors other than the surgeon. Residual pain was assessed using the visual analogue scale. The subjective and objective results were assessed using the modification of Gartland and Werley’s (1951) demerit point system described by Sarmiento et al. (1975), which is commonly used to assess outcome of management of wrist fractures. The range of movement of the wrist was measured using a goniometer, finger flexion was measured as the distance between the tips of the fingers and the distal palmar crease on maximum active finger flexion. Grip strength was measured using a Jamar dynamometer, recording the best of three readings at setting 2. Radiographs taken at the time of injury were used to obtain the Frykman classification of each fracture (Frykman, 1967) (Fig 2a). Radiographs taken at the time of surgery, at 6 and 12 weeks and at the time of this review were compared (Figs 2c–e). The intraoperative radiographs and the radiographs taken at the time of this review were standardized for the position of the shoulder and elbow and only these two X-rays were used for the final comparison of maintenance of reduction. All the X-rays were digital images so comparative assessment of radial length could be accurately done using the digital scale. Radial length was measured along the ulnar margin with reference to the most distal aspect of the ulnar head (Kreder et al., 1996). Radial and palmar inclinations were measured according to the system described by Gartland and Werley (1951). We defined a satisfactory reduction as a loss of less than 101 of palmar tilt (i.e. no dorsal angulation beyond neutral), less than 2 mm of radial length (i.e. radial articular surface no shorter than the ulnar articular surface at the Table 1—Pain score (visual analogue scale) Pain score
No. of patients
0 1 2 3 4 5 6 7 or more
13 1 6 2 1 2 1 0
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level of the radiocarpal joint) and less than 1 mm of joint incongruity. We accepted 161 of radial inclination as satisfactory.
RESULTS A total of 26 patients were available for review. The length of follow-up was 17 (range 7–31) months. Thirteen patients had a pain score of zero (Table 1). The median pain score was 0.5 (range 0–6). One patient who had plate failure with complete loss of reduction at 6 weeks had a pain score of 4. One patient with a pain score of 5 had lost radial length at 12 weeks and required an ulna matching procedure. The other patient with a pain score of 5 had an acceptable radiological result and no other clinical complications to explain the persistent pain. The patient with a pain score of 6 had lost radial length and palmar inclination at 12 weeks, but refused further surgery. The Gartland and Werley score was excellent or good in 21 patients, fair in three and poor in two. Two patients with fair results and one with a poor result had lost the reduction achieved at the time of surgery by 12 weeks. One patient with a fair result had persistent pain without any clinical complications or radiological evidence of malunion. The remaining patient with a poor result had persistent dorsal angulation at the end of the initial operation and sustained a rupture of the extensor digitorum communis tendon to the middle finger at 20 weeks. The range of movements of the injured and normal wrists are shown in Table 2. Tethering of the finger extensors and resultant loss of flexion is a potential complication following any wrist pathology and dorsal intervention. We did not encounter this problem at any stage of the follow-up and, at final review, all patients could flex their fingers to reach the distal palmar crease. The mean grip strength was 70% of the uninjured side, measuring 22 (range 3–50) kg on the injured side and 31 (range 8–52) kg on the uninjured side. Based on the radiological criteria defined above, satisfactory reduction was achieved at surgery in 22 of the 26 patients. Two patients had articular steps greater than 1 mm, one patient had 2 mm of radial shortening and one patient had a persistent dorsal angulation of 51 beyond neutral. All these patients with less than satisfactory initial reductions maintained the positions achieved at surgery throughout the period of follow-up.
Table 2—Mean ranges of movement in degrees (range) of the injured and normal wrists
Injured Normal
Dorsiflexion
Palmarflexion
Ulnar deviation
Radial deviation
Supination
Pronation
45 (21–48) 55 (20–80)
54 (42–63) 71 (54–95)
29 (17–34) 39 (20–55)
14 (8–18) 16 (5–23)
82 (84–90) 87 (70–95)
86 (86–90) 88 (75–90)
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Five patients had lost the reduction achieved at surgery. In one, the reduction was lost at 6 weeks and, in the remaining four, between 6 and 12 weeks. All these patients had severe dorsal comminution resulting in a substantial metaphyseal gap following restoration of length and inclination. The metaphyseal gap measured on the intraoperative radiograph was 8 mm (range 6–11 mm). Three patients had lost radial length (3 mm, 3 mm, 5 mm, respectively) and two patients had lost both radial length and palmar inclination (2 mm, 61 beyond neutral and 5 mm, 141 beyond neutral, respectively). There was one plate failure with complete loss of reduction evident at 6 weeks. The bio-absorbable plate was found to be broken at the time of revision with a stainless-steel, low-profile plate and iliac crest bone graft. In this patient, the eventual functional result was good. Two patients with radial shortening required ulnar matching procedures to restore pain free forearm rotation. The eventual functional score was good. Complications One patient developed a wound infection, which was superficial and resolved with oral antibiotics. Extensor tenosynovitis occurred between 4 and 12 weeks following surgery in two patients and responded within 2 weeks to antiinflammatory medication and temporary splintage. There was one ruptured EPL tendon, which was repaired directly, and one middle finger extensor digitorum communis tendon rupture, which was treated by extensor indices transfer. There were two cases of inflammatory reaction associated with plate resorption, which occurred between 8 and 11 weeks after surgery. One presented with painful swelling and erythema overlying the plate. This was treated by aspiration and the reaction resolved gradually over the next 6 weeks. The final result was excellent. The other, more severe, reaction started as a papule with surrounding erythema. The papule spontaneously ruptured to produce a sinus tract with discharge of fragments of the plate. This patient was taken to theatre for formal debridement. There was florid synovitis with fragments of plate interposed within the soft tissues. The histology reported a non-specific granulomatous reaction. Following debridement, the inflammatory reaction settled over the next 4 weeks and the eventual functional result at final review was excellent.
DISCUSSION The Reunite, bio-absorbable, dorsal distal radius plate is composed of 82% polymerized l lactic acid and 18% polymerized glycolic acid. Manufacturers’ bench test data comparing this material with equivalent metal plates subjected to flex and tensile tests have demonstrated equal, or greater, peak loads up to 6 weeks
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(Sarver, 1995). After this time, the slope of the stress–strain curve increases due to increasing brittleness. In vivo testing, in canine models, has shown that this material retains its strength for 6 to 8 weeks and complete mass loss occurs at 1 year (An et al., 1998). This allows gradual load transfer to the healing bone and obviates the need to remove retained implants for mechanical problems. Another advantage is the radiolucency of the plates and screws, which is said to facilitate postoperative radiographic evaluation. However, this can give rise to difficulties when applying the plate and screws, as it is not possible, using intraoperative imaging, to detect screws that are too close to the articular surface, or too long. All the fractures treated in this series were potentially unstable and, therefore, had metaphyseal defects as a result of dorsal comminution. It is our practice to address metaphyseal defects using either bone graft or bone substitute, irrespective of the method of internal fixation, and, as such, we have no experience of using the plate alone without bone substitute. Autologous bone graft is most commonly used for filling voids in fracture surgery and it remains the gold standard among graft materials. It has the advantage of being osteoinductive and osteoconductive. It stimulates healing and is incorporated into the host bone. However, there is significant morbidity associated with autologous grafting (Ladd and Pliam, 2001). There is an increase in operative time, blood loss, postoperative pain, length of hospital stay and cost. Infection and fractures at the donor site are other possible complications. Bone substitutes have, therefore, emerged as an alternative to improve the outcome. Biobon is composed of calcium phosphate. Reconstitution using normal saline induces a hydraulic curing process that results in a microcrystalline hydroxyapatitic paste that hardens endothermically at body temperature (37 1C). There is evidence that calcium phosphate bone substitute (Norian SRS; Norian, Cupertino, California) improves outcome of distal radius fractures (Cassidy et al., 2003; Kopylov et al., 1996). The clinical effectiveness of Biobon has been reported in the German literature in a study of 29 patients with an average follow-up of 18 months (Linhart et al., 2003). Unstable distal radius fractures were treated with Biobon and additional osteosynthesis. The average outcome using the Gartland and Werley (1951) score was 7.5 (range 2–21) points, representing a good result. These authors concluded that Biobon was a good alternative to autologous bone graft, especially in elderly patients. The range of movement, grip strength and Gartland and Werley scores achieved in this series are comparable with that of similar studies involving dorsal plating of intraarticular distal radius fractures using low-profile metal plates and autologous bone graft where necessary (Tables 3 and 4). The major advantage was avoidance of a second operation for plate removal, the incidence of which varies between 12% and 29% in the literature (Axelrod and McMurtry, 1990; Campbell, 2000; Carter
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et al., 1998; Jakob et al., 2000; Ring et al., 1997). Reoperation leads to further scarring with contracture of the dorsal capsule and extensor sheath with the potential to produce further stiffness. In this series, we had two reoperations for problems relating to malfunction of the implant, which compares favourably with the reoperation rates associated with metal plates as mentioned above. One re-operation was to revise a broken plate at 6 weeks in a fracture with severe dorsal comminution and the other was for exploration and debridement of the inflammatory reaction associated with plate resorption at 11 weeks. Extensor tenosynovitis and tendon ruptures are well documented complications following dorsal plating of distal radius fractures (Table 5). Tendons rupture as a result of a combination of mechanical attrition and devascularisation (Kozin and Wood, 1993). EPL ruptures can occur in association with undisplaced fractures. This tendon has a relatively avascular area adjacent to Lister’s tubercle. Fracture comminution, oedema, haematoma or osseous pressure can compro-
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mise the blood supply further, leading to ischaemic rupture. Attrition ruptures occur as a result of tendon fraying over callus, malunited fragments or prominent implants used for fixation. In this series, the single EPL rupture was of the typical part of the tendon, adjacent to Lister’s tubercle. At exploration, neither of the two ruptured tendons had the frayed appearance of an attrition rupture. There was evidence of synovitis around the tendons and we believe that the ruptures were due a combination of relative ischaemia and inflammatory pathology, as seen in rheumatoid patients. Five patients lost the reduction achieved at surgery. As the loss of reduction occurred between 6 and 12 weeks postoperatively and as the plate retains its strength for 8 weeks, it appears logical that for wrists with severe dorsal comminution, the bio-absorbable plate did not retain its strength for long enough to allow adequate fracture healing for load transfer. Indeed, in a similar series of fractures, with similar follow-up, treated with low-profile titanium plates, 36% of the fractures
Table 3—Gartland and Werley scores compared with other studies Campbell (2000)
Carter et al. (1998)
Jakob et al. (2000)
Ring et al. (1997)
This study
No. of patients Follow-up (months)
25 16
73 18.5
74 12
22 14
26 16.6
Gartland and Werley score (no. of patients) Excellent Good Fair Poor
4 11 10 0
59 10 4 0
62 10 2 0
6 7 9 0
15 6 3 2
Table 4—Mean range of movement (degrees) and grip strength (% of uninjured side) compared with other studies Campbell (2000)
Carter et al. (1998)
Ring et al. (1997)
This study
60 40 — — 90 90 76
58 52 31 20 82 82 87
45 40 21 14 65 76 56
45 54 29 14 82 86 70
Dorsiflexion Palmer flexion Ulnar deviation Radial deviation Supination Pronation Grip strength
Table 5—Extensor tendon related complications following dorsal plating of the distal radius
No. of patients Tenosynovitis Tendon rupture
Campbell (2000)
Carter et al. (1998)
Jakob et al. (2000)
Ring et al. (1997)
This study
25 3 1
73 8 0
74 3 5
22 5 0
26 2 2
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united at 3 months and all united at 6 months (Campbell, 2000). All these patients had severe dorsal comminution resulting in a substantial metaphyseal gap following restoration of length and inclination. By contrast, the four patients with less than satisfactory initial reduction did not lose the position achieved, as the postreduction metaphyseal gap in these fractures was not large enough to prevent healing before loss of strength of the plate. Possible solutions to this problem are to use a plate that will retain its strength for longer for more comminuted fractures or to accelerate the rate of healing by using osteoinductive material, such as cancellous bone graft, to fill the metaphyseal gap. Following this experience, we continue to use the bio-absorbable plate with calcium phosphate bone substitute for unstable intraarticular distal radius fractures that are not suitable for non-operative management (Bartosh and Saldana, 1990) because of articular incongruity or dorsal comminution, provided the metaphyseal gap following reduction does not exceed 7 mm. We use metal plates, with calcium phosphate bone substitute, for treating fractures with severe dorsal comminution with a metaphyseal gap of greater than 7 mm following reduction and additional cancellous bone graft when the metaphyseal gap is greater than 10 mm. The reported complications of bio-absorbable implants include painful erythema, sterile sinus track formation, hypertrophic fibrous encapsulation and, in severe cases, osteolysis (Ciccone et al., 2001). Bo¨stman and Pihlajama¨ki (2000), in a review of 2528 patients treated with bio-absorbable implants, reported an overall incidence of 4% of clinically significant, local inflammatory, sterile tissue reaction. This was reported, histologically, as a non-specific, foreign body reaction. This inflammatory reaction is due to the biological response to the degradation products of the bioabsorbable implants. This degradation follows a specific pattern (Ciccone et al., 2001). There is, initially, a loss of molecular weight, followed by loss of strength and, finally, a loss of mass. The initial phase of degradation is chemical, followed by a biological processing and implant removal that is responsible for the inflammatory response. The most symptomatic reactions have been associated with the more rapidly degrading polymerized glycolic acid. The incidence is 5.3%, as compared to 0.2% with polymerized l lactic acid. Polymerized l lactic acid has been associated with delayed reactions as late as 4.3 years after surgery (Bo¨stman and Pihlajama¨ki, 1998). The rate of degradation and, hence, the inflammatory response can be modulated by altering the proportions of the constituent polymers. The co-polymer ratio in the Reunite bioabsorbable dorsal distal radius plate appears to have reduced the risk of reaction. The two cases of inflammatory reaction in our series occurred at 8 and 11 weeks following surgery. As the plate undergoes
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complete mass loss in 12 months, the risk of a late reaction after that time is unlikely. Nineteen patients in our series had a follow-up of greater than 12 months. We have not had any complaint to date from the remaining patients. Hopefully, further development of the bio-absorbable plates will make them more universally applicable for treating a greater part of the spectrum of unstable distal radius fractures, by increase of the length of time for which they retain their strength, while maintaining the current low incidence of inflammatory complications. References Axelrod TS, McMurtry RY (1990). Open reduction and internal fixation of comminuted, intraarticular fractures of the distal radius. Journal of Hand Surgery, 15A: 1–11. An YH, Friedman RJ, Powers DL, Draughn RA, Latour Jr. RA (1998). Fixation of osteotomies using bioabsorbable screws in the canine femur. Clinical Orthopaedics and Related Research, 355: 300–311. Bartosh RA, Saldana MJ (1990). Intraarticular fractures of the distal radius: a cadaveric study to determine if ligamentotaxis restores radiopalmar tilt. Journal of Hand Surgery, 15A: 18–21. Bo¨stman OM, Pihlajama¨ki HK (1998). Late foreign-body reaction to an intraosseous bioabsorbable polylactic acid screw: a case report. Journal of Bone and Joint Surgery, 80A: 1791–1794. Bo¨stman OM, Pihlajama¨ki HK (2000). Adverse tissue reactions to bioabsorbable fixation devices. Clinical Orthopaedics and Related Research, 371: 216–227. Campbell DA (2000). Open reduction and internal fixation of intra articular and unstable fractures of the distal radius using the AO distal radius plate. Journal of Hand Surgery, 25B: 528–534. Carter PR, Frederick HA, Laseter GF (1998). Open reduction and internal fixation of unstable distal radius fractures with a lowprofile plate: a multicenter study of 73 fractures. Journal of Hand Surgery, 23A: 300–307. Cassidy C, Jupiter JB, Cohen M, Delli-Santi M, Fennell C, Leinberry C, Husband J, Ladd A, Seitz WR, Constanz B (2003). Norian SRS cement compared with conventional fixation in distal radius fractures: a randomized study. Journal of Bone and Joint Surgery, 85A: 2127–2137. Ciccone WJ II, Motz C, Bentley C, Tasto JP (2001). Bioabsorbable implants in orthopaedics: new developments and clinical applications. Journal of the American Academy of Orthopaedic Surgeons, 9: 280–288. Dao KD, Shin AY, Berger RA (2000). T incision for exposure of the distal radius and wrist. Journal of Hand Surgery, 25B: 544–547. Fitoussi F, Ip WY, Chow SP (1997). Treatment of displaced intraarticular fractures of the distal end of the radius with plates. Journal of Bone and Joint Surgery, 79A: 1303–1312. Frykman G (1967). Fracture of the distal radius including sequelae – shoulder–hand–finger syndrome, disturbance in the distal radioulnar joint and impairment of nerve function. A clinical and experimental study. Acta Orthopaedica Scandinavica, Supplementum: 108. Gartland Jr JJ, Werley CW (1951). Evaluation of healed Colles’ fractures. Journal of Bone and Joint Surgery, 33A: 895–906. Jakob M, Rikli DA, Regazzoni P (2000). Fractures of the distal radius treated by internal fixation and early function: a prospective study of 73 consecutive patients. Journal of Bone and Joint Surgery, 82B: 340–344. Kopylov P, Jonsson K, Thorngren KG, Aspenberg P (1996). Injectable calcium phosphate in the treatment of distal radial fractures. Journal of Hand Surgery, 21B: 768–771.
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Kozin SH, Wood MB (1993). Early soft-tissue complications after fractures of the distal part of the radius. Journal of Bone and Joint Surgery, 75A: 144–153. Kreder HJ, Hanel DP, McKee M, Jupiter J, McGillivary G, Swiontkowski MF (1996). X-ray film measurements of healed distal radius fractures. Journal of Hand Surgery, 21A: 31–39. Ladd AL, Pliam NB (2001). The role of bone graft and alternatives in unstable distal radius fracture treatment. Orthopaedic Clinics of North America, 30: 337–351. Linhart W, Briem D, Schmitz ND, Priemel M, Lehmann W, Rueger JM (2003). Treatment of metaphyseal bone defects after fractures of the distal radius. Medium-term results using calcium-phosphate cement (BIOBON). Unfallchirurg, 106: 618–624. Rikli DA, Regazzoni P (1996). Fractures of the distal end of the radius treated by internal fixation and early function: a preliminary report of 20 cases. Journal of Bone and Joint Surgery, 78B: 588–592. Ring D, Jupiter JB, Boston, Brennwald J, Bu¨chler U, Hastings H (1997). Prospective multicenter trial of a plate for dorsal
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fixation of distal radius fractures. Journal of Hand Surgery, 22A: 777–784. Sarmiento A, Pratt GW, Berry NC, Sinclair WF (1975). Colles’ fractures: functional bracing in supination. Journal of Bone and Joint Surgery, 57A: 311–317. Sarver D. Mechanical testing of the Lactosorb 2 mm trauma plates in comparison with metallic fixation. Warsaw, IN, Biomet Inc., 1995. Received: 7 October 2004 Accepted after revision: 15 September 2005 No funding or benefits in any form have been or will be received by any of the authors from any of the commercial parties related to the subject of this paper. Mr S. Gangopadhyay, 108 Abbey Road, West Bridgford, Nottingham NG2 5NB, UK. Tel.: +441159235029; fax: +441702221088. E-mail: [email protected]
r 2005 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2005.09.015 available online at http://www.sciencedirect.com