|Year : 2019 | Volume
| Issue : 12 | Page : 1715-1721
Factors influencing the functional outcomes of tibia plateau fractures after surgical fixation
B Polat1, T Gurpinar2, AE Polat3, Y Ozturkmen2
1 Department of Orthopaedics and Traumatology, Faculty of Medicine, University of Kyrenia, Istanbul, Turkey
2 Department of Orthopaedics and Traumatology, Istanbul Education and Research Hospital, Istanbul, Turkey
3 Department of Orthopaedics and Traumatology, Dr. Akçiçek State Hospital, Kyrenia, Cyprus
|Date of Submission||21-Aug-2018|
|Date of Acceptance||23-Jul-2019|
|Date of Web Publication||3-Dec-2019|
Dr. B Polat
Tesbih Sokak No: 2 Lapta/Girne K.K.T.C. Mersin 10
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Aims: The aim of this study is to assess the functional and radiological outcomes of 52 surgically treated tibial plateau fractures and to determine the factors affecting functional outcomes. Subjects and Methods: A total of 52 patients who were operated between 2007 and 2014 due to tibial plateau fractures were retrospectively reviewed. The Knee Society Score (KSS) was used for the functional outcome assessment. The Kellgren–Lawrence radiological evaluation score was used for the relationship between postoperative trauma and osteoarthritis in the last follow-up. Results: Patients' mean age was 47.7 years (range, 14–84 years). The immobilization period was 4.2 weeks (range, 0–8 weeks), the full weightbearing time was 3.3 months (range, 1.5–5 months), and the follow-up time was 47 months (range, 17–102 months). Patients' mean KSS was 84.3 (range, 40–100). According to the Kellgren–Lawrence classification, 26 patients had grade 0, 11 patients had grade 1, 8 patients had grade 2, 5 patients had grade 3, and 2 patients had grade 4 postoperative osteoarthritis. Conclusion: Use of graft if there is collapse on joint surface, early knee motion, and early started full weightbearing after surgical fixation of tibial plateau fracture is essential for successful outcome. Findings of osteoarthritis on X-rays are not related to poor functional outcome at the mid- to long-term follow-up of surgical treated tibial plateau fractured patients.
Keywords: Functional outcome, knee fracture, Schatzker classification, tibial plateau fracture
|How to cite this article:|
Polat B, Gurpinar T, Polat A E, Ozturkmen Y. Factors influencing the functional outcomes of tibia plateau fractures after surgical fixation. Niger J Clin Pract 2019;22:1715-21
|How to cite this URL:|
Polat B, Gurpinar T, Polat A E, Ozturkmen Y. Factors influencing the functional outcomes of tibia plateau fractures after surgical fixation. Niger J Clin Pract [serial online] 2019 [cited 2022 Dec 2];22:1715-21. Available from: https://www.njcponline.com/text.asp?2019/22/12/1715/272207
| Introduction|| |
Tibial plateau fractures (TPFs) are intraarticular fractures that account for 1% of all fractures in adults. TPFs are injuries that are difficult to manange that can be caused by different articular compression, displacement, and soft tissue injuries such as menisci and ligaments in spite of improvements that have been made to surgical techniques and implants. The purpose of tibial plateau surgery is to obtain a painless, ligamentous stable, and full functional recovery with sufficient range of motion in the knee joint. To achieve this, anatomic reduction as well as reconstruction of the joint line and rigid internal fixation must be performed.
Most authors recommend grafting after restoration of the articular surface., Some authors have reported that grafting is not needed if the subchondral bone is supported with screws in buttress plating. In bicondylar TPFs, some authors suggest double plating, while others suggest that single lateral plating is sufficient. Although satisfactory results have been reported with percutaneous screw fixation after restoration of the articular surface in lateral TPFs, other studies have reported worse functional outcomes with this treatment. In addition, the onset of knee motion and weightbearing after TPFs surgery are controversial. Implant selections, use of grafts for surgical treatment of TPFs, onset of knee motion, and weightbearing after TPFs surgery still remain controversial, despite the plethora of studies.
The aim of this study is to assess the mid- to long-term functional and radiological outcomes of 52 surgically treated TPFs and to determine the factors affecting functional outcomes.
| Materials and Methods|| |
Study population and database
After obtaining institutional review board approval (Approval no. 585), we retrospectively reviewed our patients who had received surgeries for TPFs between 2007 and 2014. During this time, operations that had been conducted on 132 consecutive patients were identified from the hospital database. This included 52 knees of 52 patients who were able to attend their routine clinical control and were willing to participate in this study.
After the injury, all patients were kept waiting until the skin around the proximal tibia was ready for surgery. Reduction of swelling, healing of fracture blister, and wrinkling of the skin around the proximal tibia are expected clinical findings before surgery. In all cases, -generation cephalosporin was used as a prophylactic antibiotic half an hour before surgery and for a duration of 48 h after surgery. The surgeries were performed under fluoroscopic control on the operating table while the patient was under general or spinal anesthesia. The insertion was achieved with an anterolateral and/or posteromedial approach, and submeniscal arthrotomy was performed to all patients to evaluate meniscal injury and to control reduction of joint level. According to the amount of collapse of the joint surface, in some patients, graft use was preferred after the joint level was reduced. Medial and/or lateral proximal tibia anatomic locked plate or 6.5-mm diameter cannulated cancellous screws were used, per fracture pattern. A postoperative long leg splint was applied until the soft tissue edema disappeared after surgery.
We also routinely use computerized tomogram (CT) scan in patients with TPFs in our clinic because it affects preoperative surgical planning. Preoperative anteroposterior and lateral X-rays and CTs of the patients' knees were retrospectively identified, analyzed, and classified according to Schaztker and AO/OTA classification by three orthopedic specialists independently. In case of disagreement between examiners, reevaluation was made until a consensus was reached. Radiological arthrosis scoring was performed according to the Kellgren and Lawrence scale classification of the patients at the postoperative last follow-up.
The Knee Society Score (KSS) was used for the functional outcome assesment. The Kellgren–Lawrence radiological evaluation score was used for the relationship between postoperative trauma and osteoarthritis. The relationship between the ages of the patients (under and over 40 years old), the duration of immobilization (up to 6 weeks and longer than 6 weeks), the time to start full weightbearing (up to 3 months and longer than 3 months), and functional scores were determined. In Schatzker type 2, 3, 4, 5, and 6 TPF patients with joint-level collapse, the relationship between graft use and functional scores was determined. The clinical results of patients with Schatzker type 2, 3, and 4 TPFs treated with plate fixation or only cannulated screw fixation were compared.
Preoperative data such as age, sex, affected side, trauma mechanisms, and fracture type according to Schatzker and AO classification were collected. SPSS 15.0 (SPSS, Chicago, IL, USA) for Windows program was used for statistical analysis. Descriptive statistics included number and percentage for categorical variables, and mean, standard deviation, minumum, and maximum for numerical variables. The independent two-group comparisons of the numerical variables were performed using Student's t-test when the normal distribution condition was provided and Mann–Whitney U-test was performed when the normal distribution condition was not provided. Comparisons in more than two groups were performed by Kruskal–Wallis test because the numerical variables were not provided normal distribution condition. Statistical significance level of alpha was accepted as P < 0.05.
| Results|| |
The mean age of the patients was 47.7 years (range, 14–84 years), where 37 patients (71.2%) were male and 15 patients (28.8%) were female. The average age of men was 47.4 years and the average age of the women was 48.4 years. In terms of the extremities of the patients, 53.8% had trauma in the left leg, whereas 46.2% were affected in the right leg. When the etiological causes are examined, 28 of our the injuires were caused by traffic crashes, 16 of them were the result of simple falls, and 8 of them were falling from height. In addition, 44 of these patients had closed fractures, 5 of which had type I, and 3 had type II open fractures according to the Gustillo–Anderson classification.
Tibial tubercle osteotomies and transpatellar tendon approaches were not used. Five patients with Schatzker type 5 or 6 fractures underwent open reduction and anatomic fixation of the joint surface by a less invasive stabilization system (LISS) plate. Fragments with collapse at the joint surface were reduced by removal from the fracture site or opening a cortical window with a bone elevator. A total of 13 patients had corticocancellous allografts, and for 2 patients, calcium-phosphate bone cement were applied to the metaphyseal spaces created to support the elevated subcondral bone fragments. In 17 patients, the simple split or split displaced fractures were fixed with 6.5 cannulated cancellous screws after the anatomic reduction [Figure 1] and [Figure 2], 31 patients were fixed with anatomically locked medial or lateral plates [Figure 3] and [Figure 4], and 4 patients with bicondylar fractures were fixed with anatomically locked medial and lateral plates [Figure 5] and [Figure 6].
|Figure 2: Postoperative (a) anteroposterior (b) lateral radiography of a patient at the 79th month|
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|Figure 3: Preoperative (a) anteroposterior (b) lateral radiography of a patient|
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|Figure 4: Postoperative (a) anteroposterior (b) lateral radiography of a patient at the 20th month|
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|Figure 5: Preoperative (a) anteroposterior (b) lateral radiography of a patient|
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|Figure 6: Postoperative (a) anteroposterior (b) lateral radiography of a patient at the 58th month|
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Fractures were classified using both Schatzker and AO/OTA classifications [Table 1]. The total hospital stay was 6.4 days (range, 3–17 days), the time from injury to operation was 3.6 days (range, 1–10 days), the postoperative hospital stay was 2.8 days (range, 2–7 days), the immobilization period was 4.2 weeks (range, 0–8 weeks), the full load bearing time was 3.3 months (range, 1.5–5 months), and the follow-up time was 47 months (range, 17–102 months).
|Table 1: Distribution of patients according to Schatzker and AO/OTA classification|
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The patients' mean KSS was 84.3 (range, 40–100). KSS was excellent in 38 (73.1%) patients, good in 7 (13.5%) patients, fair in 4 (7.7%) patients, and poor in 3 (5.8%) patients. When the knee X-rays in the last follow-up were assessed according to the Kellgren–Lawrence classification of osteoarthritis, it was found that 26 (50%) patients had grade 0, 11 (21.1%) patients had grade 1, 8 (15.4%) patients had grade 2, 5 (9.6%) patients had grade 3, and 2 (3.8%) patients had grade 4 postoperative osteoarthritis. Surgical area infection was detected in five patients at the postoperative period, while three patients healed with superficial debridement and antibiotic treatment at the postoperative month. For the other 2 patients, it was necessary to remove the hardware at the third and fifth months posoperatively, despite deep serial debridement and antibiotherapy.
According to Schatzker classification, type I, II, and III fracture patients with low-energy trauma and type IV, V, and VI patients with high-energy trauma were compared through KSS and postop Kellgren–Lawrence radiological evaluation scores. No statistically significant results were found for higher values [Table 2]. When the passive knee flexion degree of the patients was evaluated at the last postoperative follow-up, the most frequent result was 0°–140° with 46.2%. The passive range of motion of the joint is as shown in [Figure 7]. When the relationship between the ages and functional scores of the patients was examined, the average KSS of patients age 0–40 years was 91.5, while the average for those over 40 years was 80.5. This was a statistically significant difference between the two age groups [Table 3]. There was no statistically significant difference between gender (P = 0.06) and the affected side (P = 0.992) of the patients and functional outcomes.
|Figure 7: Patients' passive knee range of motion ratios at the last follow-up|
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Functional scores of KSS (P = 0.029) were found to be statistically significant with the use of grafts in the Schatzker type 2, 3, 4, 5, and 6 tibia plateau fracture patients with joint-level collapse. When the immobilization duration of the patients was longer than 6 weeks, the KSS decreased, although this was not statistically significant. After the patients had been bearing full weight for 3 months, the average KSS decreased statistically significantly [Table 4]. KSS (P = 0.816) and Kellgren–Lawrence radiological evaluation (P = 0.286) were found to be statistically insignificant, even though those gave better results in patients treated with plate fixation rather than just cannulated screw fixation in Schatzker type 2, 3, and 4 tibia plateau fractures. A statistically significant difference was found between the fracture pattern (open or not) and complications (superficial wound infection) (P = 0.040).
|Table 4: The effect of patients on functional scores of immobilization time and weightbearing time|
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| Discussion|| |
The surgical implant should be selected according to the type of TPF. Screws may be sufficient in Schtazker type 2, 3, and 4 fractures if the fracture is not comminuted or displaced. Otherwise, a plate or external fixator can be used. A biomechanic study showed that locking screw plate constructions are superior to cannulated screws for fixation stability and allow early weightbearing after lateral TPFs. In our study, KSS (P = 0.816) and Kellgren–Lawrence radiological evaluation (P = 0.286) were found to be statistically insignificant, even though those gave better results in patients treated with plate fixation rather than just cannulated screw fixation in Schatzker type 2, 3, and 4 tibia plateau fractures. The selection of implants in bicondylar TPFs is also controversial. Some authors advocate that a single lateral plate is sufficient, while others advocate the use of double plates. Our study involves 12 bicondylar TPFs. Four of them were treated with double plates, and the mean KSS was 84.8. Eight of them were treated with single lateral plate, and the mean KSS was 80.2. The authors suggest that a double-plate application should be preferred in bicondylar TPFs to achieve better clinical results.
Today, the generally accepted concept on the use of grafts in the surgical treatment of TPFs is that the underlying defect is supported by bone graft when the collapsed fragment is elevated to the joint level. Various grafts can be used, including autogenous cortical and cancellous grafts, allografts, calcium phosphate bone cement, and calcium sulfate bone cement., Lachiewicz and Funcik reported worse results without using bone grafts. In our study, in accordance with the literature, KSS (P = 0.029) was significantly increased with the use of grafts in Schatzker type 2, 3, 4, 5, and 6 tibia plateau fracture patients with joint-level collapse.
There is no consensus on exactly when the patients with tibia plateau fractures will start to have knee motion after surgery. Early postoperative motion is important for the reduction of knee joint stiffness, synovial adhesion, and capsule contraction and increased cartilage healing., On the other hand, starting early motion after surgery can lead to a loss of reduction and deterioration of fixation. The study by Blokker et al. reported that starting the knee movements immediately after the operation or 2 weeks later did not make any difference after 3 years of follow-up. For this reason, the approach taken in our clinic is to immobilize the knee with a long leg splint to allow soft tissue healing in the 0–8 weeks according to the degree of soft tissue swelling in the postoperative period. Our study showed that the immobilization duration of the patients is longer than 6 weeks; the KSS is decreased even if it is not statistically significant. After this clinical study, immobilization in postoperative tibia plateau fractures is not performed for more than 2 weeks by the authors.
The time to start weightbearing after surgery remains a subject of debate. Some studies recommend weightbearing immediately within the brace, indicating that it stimulates fracture healing., Conversely, other studies recommend that weightbearing should be delayed by up to 12 weeks. Early weightbearing after TPF surgery may cause a loss of reduction and malunion. The time to start to weightbearing should be determined on the basis of the patient's weight, the amount of atrophy in the muscles around the knee, and the quality of the fixation rigidity. Our study demonstrated that when full weightbearing after TPF surgery is delayed by more than 12 weeks, the KSS decrease is statistically significant. After this study, we have started to give partial load after 6 weeks postoperatively and full weightbearing between 6 and 12 weeks, according to the condition of the patient mentioned above.
Tscherne and Lobenhoffer reported 4% deep and 4% superficial infection, Blokker et al. reported 7.9% deep and 5.3% superficial infection, while Rasmussen reported 0.9% deep and 4.2% superficial infection.,, In our study, 2 (3.8%) patients had deep wounds infection, whereas superficial wound infection was detected in 3 (5.7%) patients. Two of the cultures from the deep wound infected patients were isolated Stapylococcus aureus, where one of these patients was reoperated for removal of plate at the third month and the other at the fifth month. There was no isolate in the cultures of the other three superficial wound infected patients. Dressing and empirical antibiotherapy provided recovery. In our study, surgical site infections were statistically significantly higher (P = 0.040) in patients with open fractures than patients with closed fractures. The prophylactic resumption of thromboembolism continued from 6 h after the surgery until the patient was well-mobilized (4–8 weeks). There was no case of thromboembolism in our study.
Although 50% of our patients had osteoarthritis findings according to the Kellgreen–Lawrance classification at the last follow-up period, 82.7% of them were evaluated as excellent in terms of KSS. This study showed that although osteoarthritis findings were determined at the mid- to long-term follow-up after surgical treatment of the TPFs, clinical outcomes were well-presented. Findings of osteoarthritis in X-ray are not related to poor functional outcome at the mid- to long-term follow-up of surgically treated tibial plateau fractured patients.
| Conclusion|| |
The mid- to long-term results of the cases treated with elevation of the joint surface for anatomic reduction, filling the metaphyseal defect with graft, and supporting this reconstruction with internal fixation are more successful. It should be considered that early knee motion and early started full weightbearing after surgical fixation of TPF are essential for successful outcome. It is possible to obtain better clinical results by plate osteosynthesis than screw fixation in Schatzker types 2, 3, and 4 tibia plateau fractures. Although radiological findings of osteoarthritis develop in mid- to long-term follow-up, the clinical results are satisfactory.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Lansinger O, Bergman B, Körner L, Anderssonn GMJ. Tibial condylar fractures: A twenty-year follow up. J Bone Joint Surg 1986;68:13-9.
Lundusi R, Gasbarra E, D'Arienzo M, Piccioli A, Tarantino U. Augmentation of tibial plateau fractures with an injectable bone substitute: CERAMENT™
. Three year follow-up from a prospective study. BMC Musculoskelet Disord 2015;16:115.
Kulkarni S, Tangirala R, Malve SP, Kulkarni MG, Kulkarni VS, Kulkarni RM, et al
. Use of a raft construct through a locking plate without bone grafting for split-depression tibial plateau fractures. J Orthop Surg 2015;23:331-5.
Rohra N, Suri HS, Gangrade K. Functional and radiological outcome of schatzker type V and VI tibial plateau fracture treatment with dual plates with minimum 3 years follow-up: A prospective study. J Clin Diagn Res 2016;10:RC05-10.
Chang H, Zhu Y, Zheng Z, Chen W, Zhao S, Zhang Y, et al
. Meta-analysis shows taht highly comminuted bicondylar tibial plateau fractures treated by single lateral locking plate give similar outcomes as dual plate fixation. Int Orthop 2016;40:2129-41.
Elsoe R, Larsen P, Rasmussen S, Hansen HA, Eriksen CB. High degree of patient satisfaction after percutaneous treatment of lateral tibia plateau fractures. Dan Med J 2016;63:A5174.
Elsoe R, Larsen P, Shekhrajka N, Ferreira L, Ostgaard SE, Rasmussen S. The outcome after lateral tibial plateau fracture treated with percutaneus screw fixation Show a tendency towards worse functional outcome compared with a reference population. Eur J Trauma Emerg Surg 2016;42:177-84.
Schatzker J, McBroom R, Bruce D. The tibial plateau fracture. The Toronto experience 1968-1975. Clin Orthop Relat Res 1979;138:94-104.
Marsh JL, Slongo TF, Agel J, Broderick JS, Creevey W, DeCoster TA, et al.
Fracture and dislocation classification compendium – 2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma 2007;21:1-33.
Petersson IF, Boegard T, Saxne T, Silman AJ, Svensson B. Radiographic osteoarthritis of the knee classified by the Ahlback and Kellgren and Lawrence systems for the tibiofemoral joint in people aged 35-54 years with chronic knee pain. Ann Rheuma Dis 1997;56:493-6.
Carrera I, Gelber PE, Chary G, Gonzalez-Ballester MA, Monllau JC, Noailly J. Fixation of a split fracture of the lateral tibial plateau with a locking screw plate instead of cannulated screws would allow early weight bearing: A computational exploration. Int Orthop 2016;40:2163-9.
McDonald E, Chu T, Tufaga M, Marmor M, Singh R, Yetkinler D, et al
. Tibial plateau fracture repairs augmented with calcium phosphate cement have higher in situ
fatigue strength than those with autograft. J Orthop Trauma 2011;25:90-5.
Lachiewicz PF, Funcik T. Factors influencing the results of open reduction and internal fixation of tibial plateau fractures. Clin Orthop Relat Res 1990;259:210-5.
Gausewitz S, Hohl M. The significance of early motion in the treatment of tibial plateau fractures. Clin Orthop 1986;202:135-8.
Hurley MV. The effects of joint damage on muscle function, proprioception and rehabilitation. Man Ther 1997;2:11-7.
Rasmussen PS. Tibial condylar fractures: Impairment of knee joint stability as an indication for surgical treatment. J Bone Joint Surg 1973;55:1331-50.
Blokker CP, Rorabeck CH, Bourne RB. Tibial plateau fractures: An analysis of the results of treatment in 60 patients. Clin Orthop 1984;182:193-9.
Segal D, Mallik AR, Wetzler MJ, Franchi AV, Whitelaw GP. Early weight bearing of lateral tibial plateau fractures. Clin Orthop Relat Res 1993;294:2327.
Haak KT, Palm H, Holck K, Krasheninnikoff M, Gebuhr P, Troelsen A. Immediate weight-bearing after osteosynthesis of proximal tibial fractures may be allowed. Dan Med J 2012;59:A4515.
Yu GR, Xia J, Zhou JQ, Yang YF. Low-energy fracture of posterolateral tibial plateau: Treatment by a posterolateral prone approach. J Trauma Acute Care Surg 2012;72:1416–23.
Schuetz M, Müller M, Krettek C, Höntzsch D, Regazzoni P, Ganz R, et al.
Minimally invasive fracture stabilization of distal femoral fractures with the LISS: A prospective multicenter study results of a clinical study with special emphasis on difficult cases. Injury 2001;32:48-54.
Tscherne H, Lobenhoffer P. Tibia plateau fractures: Management and expected results. Clin Orthop 1993;292:87-100.
Van Dreumel RL, Van Wunnik BP, Janssen L, Simons PC, Janzing HM. Mid- to long-term functional outcome after open reduction and internal fixation of tibial plateau fractures. Injury 2015;46:1608-12.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
[Table 1], [Table 2], [Table 3], [Table 4]
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