Guo Yongji, Li Ruishan, Sun Rongchun*, Department of Orthopaedics, Nanhai District Third People’s Hospital, Foshan City, China
Abstract Objective To investigate the factors associated with the prognostic complications of fractures in and around the knee joint. Methods A retrospective review of 68 cases of C3 fractures of the knee and its periphery in recent years was conducted to analyze and compare the correlation between the prognostic complications of fractures and factors such as combined injuries, missed diagnosis, treatment selection, inadequate treatment and functional exercise of fractures. Results There was no significant difference between other factors and prognostic complications of fractures except for the under-treatment and method selection groups (p<0.05) (p>0.05). Conclusion Combined injuries, missed diagnosis, and treatment methods of fractures, and factors such as under-treatment and functional exercise can affect the occurrence of prognostic complications of C3 fractures in and around the knee joint.
Type C3 fracture in and around the knee joint is a common fracture, mostly caused by high energy. The prognosis after the fracture is often complicated by the severity of the injury in and around the joint. Inadequate treatment is the most influential factor when evaluating the prognosis of periprosthetic knee fractures for complications. In addition, some scholars have suggested that the influencing factors of complications include the combined injury of the fracture, missed diagnosis, functional exercise, and treatment choice. Currently, there is debate in the literature as to whether these factors are associated with the occurrence of complications, and there is a lack of statistical analysis. In this paper, we retrospectively analyzed the data of 68 patients with periprosthetic C3 fractures treated at our hospital in an attempt to understand whether factors such as combined injury, missed diagnosis, method selection, inadequate treatment, and functional exercise were associated with the occurrence of prognostic complications.
I Data and methods
1.1 General data
We reviewed 68 cases of periprosthetic C3 fractures admitted to our hospital from 2000 to 2007. (Complications referred to in this paper refer to those with a knee HSS functional score less than 59, combined with pain, joint stiffness, deformity, etc. that seriously affects life, more than 16 months after fracture treatment, hereinafter). The inclusion criteria were: 1. significant changes in knee shape, with an external (internal) valgus angle greater than 30 degrees; 2. limited joint movement, with extension <5° and flexion between 0° and 105°; 3. severe pain symptoms affecting the patient's work life; 4. significant abnormalities on imaging and arthroscopy. Those who meet any two of these criteria or more are considered to have prognostic complications. Complications due to rheumatoid, osteoarthritis, and non-traumatic septic arthritis were excluded. Thirty-two cases were eligible. Among them, 23 cases were male and 9 cases were female, the oldest was 64 years old, the youngest was 21 years old, and the average was 43 years old. There were 13 left-sided cases and 19 right-sided cases. The causes of injury: 14 cases were caused by car accidents, 8 cases were caused by falling from high places, 5 cases were caused by heavy objects, 4 cases were caused by crush injuries, and 1 case was caused by others.
1.2 Methods
The determination of whether there was inadequate treatment was based on the original, intraoperative, and short-term postoperative radiographs and CT data. Intraoperative radiographs showing a difference of more than 1 cm in the joint surface after repositioning or a deviation of 5° in the coronal and sagittal force lines were defined as poor repositioning, while compared with postoperative radiographs, if the fracture block collapsed more than 1 cm at follow-up or the coronal and sagittal force lines >5° were called fracture re-displacement. Short-term postoperative radiographs showing poor fracture repositioning or re-displacement of the fracture after fixation or loosening of the internal fixation were considered under-treatment. There were 12 cases of under-treatment in this group, mostly caused by missed diagnosis before treatment, poor fracture repositioning during treatment, and poor internal fixation, while there were 56 cases in the adequately treated group; intraoperative and postoperative radiographs, CT arthroscopy, and MIR were also used to determine whether there was a missed diagnosis. There were 24 cases of missed diagnosis and 44 cases in the no-miss group, which were mainly missed diagnosis of periarticular meniscus injury, fork ligament injury, femoral condyle and tibial plateau coronal plane fracture. Active functional exercise as prescribed by the doctor was the correct functional exercise group, with 47 cases. Of the 68 patients, 22 had combined injuries, mainly combined with severe craniocerebral injury, liver and spleen rupture and thoracolumbar fracture. For the treatment of C3 fractures around the knee, surgical treatment was the main treatment. 36 cases were treated with minimally invasive surgery, with the most number of LISS plate internal fixation (31 cases), retrograde intramedullary nailing (3 cases), and arthroscopic treatment combined with external fixation frame in 2 cases. Non-minimally invasive treatment was performed in 32 cases, including 4 cases of non-operative treatment and 28 cases of general open surgery; except for 2 cases of open fractures that were operated on urgently, all fractures were treated with short-term traction of the affected limb before surgery. The non-operative treatment was mainly bone traction of the affected limb. The average traction time was (7±3.4)d.
1.3 Postoperative follow-up
The follow-up mainly included subjective symptoms, joint shape, mobility, stability, and imaging examinations. The follow-up period ranged from 12 to 20 months, with a mean of 16 months. 32 of 68 cases had prognostic complications. Among them, 24 cases had severe joint pain, 28 cases had traumatic arthritis, 13 cases had significantly reduced joint mobility (range 10°-60°), and 9 cases had obvious joint deformity. 18 cases had a combination of multiple symptoms and abnormal signs.
1.4 Statistical treatment
For the purpose of statistical analysis, LISS plate, retrograde intramedullary nailing, and arthroscopic surgery were defined as minimally invasive treatment, while non-surgical treatment and traditional open plain compression plate were defined as non-minimally invasive treatment; the diagnosis not found in the preoperative examination was defined as missed diagnosis, while the opposite was defined as non-missing diagnosis; during the surgical treatment, the fracture was not satisfactorily repositioned or not firmly fixed or part of the affected area was not treated at all was under-treated. Fisher’s exact probability test was used to analyze whether the factors of combined injury, missed diagnosis, treatment selection, under-treatment and functional exercise were related to the occurrence of prognostic complications, and the X2 test was used to test whether functional exercise was in place or not, and the difference was considered statistically significant at P < 0.05.
Figure 1 Preoperative front and side view Figure 2 Preoperative CT film Figure 3 Two weeks postoperative Figure 4 18 months postoperative knee valgus traumatic arthritis
Results
Complications occurred in 32 of 68 patients. The results of complications by treatment were; 4 cases (11%) in the minimally invasive surgical treatment group (36 cases) and 12 cases (38%) in the non-minimally invasive treatment group (32 cases). The difference was statistically significant (P=0.0202); 6 cases (25%) in the group with leakage (24 cases) had complications, while 8 cases (19%) in the group without leakage (44 cases) had complications, and the difference was not statistically significant (P=0.5415). Complications occurred in 7 (47%) cases in the group with combined injuries (15 cases) compared to 9 (22%) cases in the group without combined injuries (41 cases). The difference was not statistically significant (P=0.1017); 7 cases (58%) in the under-treated group (12 cases) had complications compared to 13 cases (23%) in the adequately treated group (56 cases), with a statistically significant difference (P=0.0316); 11 cases (23%) in the correct functional exercise group (47 cases) had complications compared to the group without correct functional exercise (21 cases) 9 cases (43%) had complications, and the difference was not statistically significant. Except for the group of delayed diagnosis and method selection, there was no significant difference in the incidence of prognostic complications in the subgroups of combined injury, inadequate treatment, and functional exercise (all P values > 0.05), suggesting that the differences between prognostic complications and combined knee injury, inadequate treatment, and functional exercise in this group of cases with C3 fractures of the knee were not statistically significant.
Table 1 Analysis of factors related to prognostic complications of C3 fractures around the knee joint
Complications
Combined injury
Missed diagnosis
Method choice
Inadequate treatment
Functional exercise
Yes No
Yes No
Minimally invasive surgery Non-minimally invasive
Present Not present
Correct Incorrect
No complications
8 41
18 36
32 20
5 43
36 12
With complications
7 12
6 8
4 12
7 13
11 9
P-value
0.1017*
0.5415*
0.0202*
0.0316*
0.1038**
* Fisher’s exact probability test ** chi-square test
Discussion
There are numerous treatment options for periprosthetic fractures. AO emphasizes anatomic reduction of the fracture end and strong internal fixation, and advocates extremely aggressive surgical treatment. BO, on the other hand, requires that the fracture end be functionally repositioned while avoiding re-injury to the periprosthetic area as much as possible to reduce the occurrence of bone discontinuity. However, regardless of the method, the prognosis of C3 fractures in and around the knee joint is often complicated by complications. Although these complications are related to the patient’s age and fracture type, the timely diagnosis, proper management and early functional exercise after the fracture also have an important impact on the occurrence of complications.
1. Combined injury
According to damage control theory, multiple injuries should follow the life-first principle, and the fracture should be treated thoroughly after the potential life-threatening factors are eliminated. However, some patients with severe combined injuries are in critical condition and require a long time for treatment, which often makes the fracture treatment lose the best time and thus increases the occurrence of complications. In our group, there were 15 cases of severe combined injuries, which were operated 10-25 days after the injury after the removal of life-threatening potential factors, and the complication rate was found to be 46.8%, which was higher than the complication rate of surgery within one week of the fracture (22.2%). The statistics, however, showed no significant difference between the two (p=0.1017), despite which the correlation needs to be further investigated. However, in any case such patients should be treated surgically as early as possible after their general condition has improved.
2. Missed diagnosis
Periprosthetic C3 fracture is a more complex fracture, complicated not only by the fracture itself, but also by the complexity of its surrounding structures. First, some fractures, such as Hoffa fractures and posterior column coronal fractures of the tibial plateau, often coexist with sagittal fractures of the femoral condyles or tibial plateau, which are hidden due to fracture shadow overlap and are sometimes difficult to distinguish on radiographs or even to detect intraoperatively. Secondly, injuries to the meniscus and ligaments are also easy to miss without careful examination. The missed diagnosis not only complicates the management of the fracture at the site of injury, but also sets the stage for the occurrence of prognostic complications. Our data show that of the 24 patients with a missed diagnosis, 25% had prognostic complications. Although the statistical data showed no significant difference between the two (P=0.5415), it is still believed that missed diagnoses increase the incidence of prognostic complications. In order to reduce complications due to missed diagnosis, it has been suggested that CT should be routinely used on admission for patients with knee injuries.
3. Method selection
The goal of periprosthetic fracture treatment is to obtain a stable, painless, well aligned and functional knee that minimizes the risk of traumatic arthritis. To achieve this goal, aggressive surgical treatment has become the consensus of scholars. In particular, LISS plates are used to treat these fractures with less injury, easier treatment, shorter operative time, and less complications compared to traditional open knee surgery. Luo Congfeng and Jiang Rui1 treated 41 cases of complex fractures around the knee using a minimally invasive system, and there were no significant complications except for one case with joint stiffness and painful movement, with an excellent rate of 90.2% after treatment. However, when using LISS plates to treat such complex fractures, if the concept, design principles, application principles, surgical indications, and operating techniques of LISS internal fixation are not properly understood, internal fixation failure may also occur, thus increasing the occurrence of complications. In our group, there was one patient with LISS internal fixation who ended up with internal fixation failure due to poor indications. Intramedullary nailing with locking and arthroscopic treatment are also minimally invasive procedures. Wang XJ, Kong RWM ② et al. used condylar plate and retrograde interlocking nail to treat distal femoral comminuted fractures for comparison, and found that the incidence of complications such as knee pain and stiffness after the latter treatment was significantly lower than that of the former. In order to meet the needs of fracture repositioning and plate placement, the traditional plate internal fixation has a long surgical incision and a lot of soft tissue stripping, resulting in postoperative joint adhesions, pain, and limitation of movement. One case in our group was fixed with a plain plate with a kyphosis pin, and the internal fixation was removed at 12 months and followed up to 18 months, resulting in 42° of knee valgus, <5° of extension, and traumatic arthritis (see Figures 1-4). The non-surgical treatment was not effective in intervening the fracture, and because of the long time of fixation of the affected limb, the fracture was prone to deformed growth and finally to reduced or lost functional activity of the joint. The prognostic complication rate of non-minimally invasive surgery was 32% in our group of cases, which was higher than that of those who underwent minimally invasive surgery (11%). The present study showed that minimally invasive surgery for periprosthetic C3 fractures significantly reduced the incidence of prognostic complications, and statistical analysis also showed a significant difference between the two (P=0.0202), meaning that there was a difference in the incidence of prognostic complications by treatment method.
4 Inadequate treatment
The principles of treatment for intra-articular fractures are anatomical repositioning of the fracture end, strong internal fixation, and early and effective functional exercise. Fractures around the knee, especially those involving the articular surface, are treated in such a way that the fracture end is not properly repositioned or is inadequately repositioned and poorly fixed due to the operator’s experience and other conditions, resulting in late complications. Phisitkul et al.3 reported high-energy proximal tibial fractures with splint fixation in 37 cases, with 7 cases of poor reduction and 3 cases of loss of reduction at follow-up, all of which were C-type unstable fractures. In contrast, Gosling4 et al. treated 68 cases with plate internal fixation for tibial plateau fractures by prospective study, and after 1-year follow-up, 23% had fracture mal-displacement and 14% had fracture re-displacement. Inadequate treatment directly contributed to the occurrence of prognostic complications. In our group, 12 cases were inadequately treated and 7 cases had complications prognostically, with an incidence of 58%. This compares with 25% in the adequately treated group. Statistical analysis also showed a significant difference between the two (P=0.0316); therefore, these fractures, especially those involving intra-articular fractures, should be repositioned anatomically as much as possible with a clear diagnosis, strong internal fixation, and repair of the damaged ligaments, cartilage, and meniscus; otherwise, the occurrence of prognostic complications is bound to increase.
5. Functional exercise
The ultimate goal of fracture treatment is to restore bone and joint function. In patients with bone and joint injuries, if post-treatment radiographs show satisfactory internal fixation and fracture healing, but the knee remains dysfunctional with extremely limited extension and flexion, this is not a successful case. The main cause of knee straightening in extension is prolonged braking in extension, which causes firm fibrous adhesions. In this study, the incidence of complications in the normal functional exercise group and the abnormal exercise group were 23.4% and 43%, respectively, and the analysis of the reasons may be related to the long time of fracture fixation and the lack of effective functional exercise in the early stage. Although there was no statistically significant difference between the two (P=0.1038), however, for periprosthetic fractures, strong internal fixation along with early exercise as possible is undoubtedly beneficial in reducing the occurrence of complications.
The results of the study showed no significant difference in the incidence of complications in the subgroups of combined fracture injury, missed diagnosis, and functional exercise, except for the under-treated and method-selective groups. Statistical results also showed no significant correlation between prognostic complications of periprosthetic fractures and the above-mentioned factors, which may be caused by the lower statistical efficacy due to the small number of cases. In addition, the uneven distribution of cases may also have affected the accuracy of the statistical results. However, we still believe that combined fracture injuries, method selection, inadequate treatment, and functional exercise can influence the occurrence of prognostic complications of C3 fractures in and around the knee joint. Treatment of this type of fracture should be carefully examined, actively treated, and minimally invasive surgery should be used as much as possible to minimize damage to the joint. This study also has certain defects, such as the study data are mostly retrospective, the periodicity of data acquisition is long, and the collected data are done by several doctors, so there is also a certain systematic error. Further analysis is needed as the data continue to accumulate and improve.
References
① Luo C.F., Jiang R. et al. Minimally invasive In-dine system for complex fractures around the knee joint. Chinese Journal of Orthopaedics 2006 , 7 : 454-458.
② Wang XJ, Kong WM, et al. Comparison of the efficacy of using condylar plates and retrograde interlocking nails in the treatment of distal femoral comminuted fractures. Chinese Journal of Orthopaedic Trauma. 2008 , 10: 99-100.
③Phisitkul P, Mckinley T, Nepola JV ,et al. Complications of locking plate fixation in complex proximal tobia injuries.J orthop Trauma,2007,21 83-91.
④ Gosling T, Schandelmaier P ,Muller M, et al. Single lateral locked screw plating of bicondylar tibial plateau fractures.Clin Orthop Relat Res, 2005,( Clin Orthop Relat Res, 2005,( 439):207-214.
⑤ Kregor PJ, Stannard J, Zlowodzki M, et al. Distal femoral fracture fixation utilizing the Less Invasive Stabilization System (_L.I.S.S):the Injury, 2001, 32(3 Suppl):SC32-SC47.