Abstract
Background:
Unicondylar fracture of distal femur accounts for less than 1% of all femoral fractures. As conservative methods have shown substandard results, traditional surgical treatment includes open reduction and internal fixation by Herbert screws, cannulated screws, and conventional lateral locking plates. Though screw fixation has excellent results over long run, there is literature documenting the loosening and loss of articular congruency in elderly patients and in comminuted fracture patterns. Also, the traditional locking plates are precontoured to fit the lateral condyle, whereas there is no specific implant to fix the medial condylar fractures. The merit of the calcaneal plating is that it is easily moldable and can be used for either of the sides irrespective of fracture pattern.
Objectives:
This study aimed to evaluate the clinical outcome of calcaneal plate (D-shape) fixation in distal femur unicondylar fractures.
Materials and Methods:
A total of 30 patients were studied, who met the inclusion criteria and consented to the surgery. After appropriate investigations, these patients were treated with calcaneal plating and were followed up postoperatively at 2 weeks, 1 month, 3 months, and 6 months for clinical evaluation.
Results:
There was a gradual increase in the range of motion (ROM) with subsequent follow-ups. The overall mean ROM evaluated at 6 months was 108.46° ± 28.27° with P < 0.001 and was a statistically significant outcome. Also, the mean ROM for sagittal split fractures (~120°) was comparatively more than the coronally split fractures (~90°). The functional outcome assessed by Neer scoring showed excellent and satisfactory results in 24 (80%) patients, whereas the remaining six (20%) patients had poor results. None of the patients had nonunion, infection, or implant failure.
Conclusion:
With no specific implant for isolated unicondylar fractures, the use of calcaneal plate in our study has shown promising results probably due to its low profile design reducing the soft-tissue irritation and wide area of bone coverage by the plate offering regions of intermittent fixation due to its spanning design, thereby promoting periosteal preservation and ultimately fracture union.
Keywords: Calcaneal plate, cannulated screws, Herbert screws, Neer scoring, ROM
Introduction
Unicondylar fracture of distal femur accounts for less than 1% of all femoral fractures and is often characterized by avulsion of one femoral condyle from metaphysis, whereas the other remains intact.[1,2,3] These injuries usually occur following direct impact, avulsion or due to shear forces on knee, sports trauma or road traffic accidents, and, particularly, dashboard trauma.[2,5,6,7] Trochlear-condylar groove is considered the critical point in these injuries, which is located at the junction between the trochlea and the medial and lateral condyles; starting from this typical site, the fracture line may be frontal, sagittal, or oblique in each condyle.[2,5] Lateral condyle is involved three times more frequently than the medial condyle in these injuries.[5,10,11] The inherent anatomical variability accounts for unique fracture characteristics, resulting in difficult radiologic evaluation and controversial therapeutic approaches.[10]
Nonoperative management has often led to unsatisfactory results due to resultant deformities (varus and valgus malangulations), varying incidences of delayed union and nonunion, joint contracture, knee instability, and posttraumatic arthritis.[12,13,14] Hence, the literature strongly recommends open reduction and internal fixation for all kinds of unicondylar femoral fractures.[8] Some traditionally used surgical treatments include internal fixation by Herbert Screws, cannulated screws, dynamic condylar screws, and conventional lateral locking plates.[3,4]
Though screw fixation has excellent results over long run, there is literature documenting the loosening and loss of articular congruency in elderly patients and in comminuted fracture patterns.[3,8] The condylar plates currently available are contoured to fit on the lateral femoral condyle surface, primarily introduced from the lateral side of the femur, whereas medial side fracture fragments are usually addressed with indirect reduction as there is no specific implant design for isolated medial condyle fracture. The merit of the calcaneal plate is that it is easily moldable and can be used for either side of the condyle irrespective of fracture pattern.[9] This study aimed to evaluate the clinical outcome of calcaneal plate fixation in distal femur unicondylar fractures.
Materials and Methods
This study was carried upon Ethical Committee approval in November 2021. It was a prospective interventional study conducted in 30 patients admitted to level 1 trauma center, with unicondylar distal femur fracture from December 2021 to November 2022. Inclusion criteria were as follows: (a) unicondylar distal femur fractures, (b) skeletally mature patients, (c) open or closed fractures, (d) patients of either gender, and (e) patients consenting for surgery and subsequent follow-up. Exclusion criteria were as follows: (a) patients with neurovascular compromise, (b) skeletally immature patients, and (c) unfit patients due to other comorbidities or polytrauma. Initially, these fractures were stabilized with groin to toe slab, prophylactic intravenous fluids and antibiotics (Inj. Ceftriaxone 2.5 g Bis in Die, Inj Amikacin 500 mg once daily), followed by appropriate investigations such as X-ray, and three-dimensional computed tomography of knee. Subsequently, these selected patients were planned for surgical intervention with calcaneal plate after obtaining prior consent. All the surgeries were performed by surgeons above the grade of assistant professors in a tertiary care center.
Surgical technique
All patients were given preoperative antibiotics. All cases were operated under spinal anesthesia in the supine position. An image intensifier with c-arm was used in all cases to provide fluoroscopic guidance.
Anterolateral approach
This approach is used for lateral unicondylar fractures of distal femur. Patient was positioned with knee flexed at 30°. Skin incision was given in the mid-lateral line of femoral shaft at Gerdys tubercle and curved proximally over the lateral condyle of femur. The skin, subcutaneous tissue, ilio-tibial band, all are incised in line, along a single plane to reach the deep muscular layer. The vastus lateralis is identified, separated along the intermuscular septum, and elevated to expose the distal femur fracture. Arthrotomy was performed as per the fracture pattern involved.[15]
Medial parapatellar approach
This approach was incorporated for the fixation of medial unicondylar fractures of distal femur. Patient was positioned with knee flexed at 30°.[15] A longitudinal, slightly oblique, medial parapatellar skin incision was given, starting from 5 cm above the superior pole of patella to tibial tubercle. The patellar retinaculum was cut open to expose the joint as per the fracture pattern the incision was extended proximally to have better visualization at the same time being cautious to avoid avulsion of patellar tendon from the tibial tubercle.
Postoperative evaluation
All postoperative patients were given posterior splint or articular splint for initial 2 days and were advised to perform active toe movements and quadriceps strengthening exercises. On postoperative day 3, assisted knee mobilization was initiated. Sutures were removed on day 14, partial weight bearing was initiated at 10–12 weeks, and progressed to full weight bearing as tolerated. Further, these patients were evaluated at 2 weeks, 4 weeks, 3 months, and 6 months clinically and radiologically. Functional outcome was analyzed using Neer scoring system [Figures 1 and 2].
Figure 1.
Functional Neer scoring
Figure 2.
Anatomical Neer scoring
Results
Demographic data and basic analysis
Of the 30 patients studied, 23 (76.67%) were male, whereas the remaining were females, indicating a clear male predominance. The majority of the patients studied clustered between the age group of 21–40 years, accounting for 60% (18 patients), whereas 20% (six patients) fell in the age group of 61–80 years, pointing to the fact that these injuries are more common in the young. The right knee was involved in 17 cases (56.67%), whereas the left knee involvement was noticed in 13 cases (43.33%). With respect to the mechanism of injury, road traffic accidents accounted for 66.67% (20 patients) of all the cases, whereas 23.33% were due to slip and fall during sports activities and the rest 9.99% due to miscellaneous mode of injury. This data supported the fact that unicondylar fractures followed a high-energy trauma, more commonly targeting young patients.
Functional outcome analysis
In our study, 18 patients had sagittal plane fractures, whereas the remaining 12 patients had coronal plane (Hoffa’s) fracture. The patients with sagittal plane fracture had a mean range of motion (ROM) of 39° ± 11.62° at 2 weeks and improved gradually with subsequent follow-ups with a mean ROM of 119.667° ± 18.79° at 6th-month follow-up with P = 0.046, which was a statistically significant outcome. Also, patients with coronal plane fractures had a mean ROM of 36.55° ± 16.24° at 2-week follow-up and improved gradually to 92.667° ± 38.419° at 6th-month follow-up. The overall mean ROM for the unicondylar fractures of distal femur treated with calcaneal plate at 6th-month follow-up was 108.46° ± 28.27° with P < 0.001, which was statistically significant and ROM showed an incremental trend with subsequent follow-ups [Table 1]. The overall functional outcome assessed at 6th month using Neer scores showed good (excellent + satisfactory) results in 24 patients (80%) and poor (unsatisfactory + failure) results in six patients (20%), with the overall P = 0.188, which was not statistically significant [Table 2].
Table 1.
Mean range of motion of patients in subsequent follow-ups
| Serial number | Follow-up (duration) | Range of motion (mean ± SD) in degrees | Range of motion (range in degrees) |
|---|---|---|---|
| 1. | 2 weeks | 38.13 ± 12.28 | 12–60 |
| 2. | 4 weeks | 62 ± 19.028 | 18–90 |
| 3. | 3 months | 86 ± 25.458 | 28–127 |
| 4. | 6 months | 108 ± 28.27 | 35–138 |
| P < 0.001a |
SD: standard deviation. aStatistically significant result, indicating that range of motion increases with duration
Table 2.
Overall functional outcome as per the type of fracture graded in accordance to Neer scoring
| Serial number | Fracture type | Excellent (A)a | Satisfactory (B)a | Unsatisfactory (C)b | Failure (D)b |
|---|---|---|---|---|---|
| 1. | Lateral condyle coronal fracture | 4 | 1 | 2 | 1 |
| 2. | Medial condyle coronal fracture | 0 | 2 | 1 | 0 |
| 3. | Lateral condyle sagittal fracture | 6 | 3 | 0 | 0 |
| 4. | Medial condyle sagittal fracture | 6 | 2 | 1 | 1 |
| 5. | Total (n = 30) | 16 | 8 | 4 | 2 |
| Chi-square testc | 5 | 3 | 3.07 | 5 | |
| P-valuec | 0.229 | 0.37 | 0.515 | 0.229 |
aA and B are considered good results in accordance with Neer Scoring. bC and D are considered poor results in accordance with Neer scoring. cThe total Chi-square value = 12.5 and P-value = 0.188, that is, no significant difference between fracture patterns
Case illustration
A 35-year-old male met with road traffic accident and presented to emergency with pain in the left knee and was subsequently diagnosed with the left unicondylar lateral distal femur fracture. Once the patient was stabilized, he was operated with calcaneal plate and was followed up for clinical and functional outcomes. At the 6th month of follow-up, patient had good ROM at the knee and was able to perform all routine day-to-day activities such as squatting and cross-legged sitting [Figures 2–10].
Figure 10.
Patient flexing knee in the supine position at 6-month follow-up
Figure 3.
Plain radiograph of lateral unicondylar distal femoral fractureantero– posterior view
Figure 4.
Plain radiograph of lateral unicondylar distal femoral fracturelateral view
Figure 5.
3-D CT of lateral distal femoral condyle fracture
Figure 6.
2-D CT of lateral distal femoral condyle fracture
Figure 7.
3 month postoperative radiograph of the same patient showing fracture union in AP view
Figure 8.
3 month postoperative radiograph of the same patient showing fracture union in lateral view
Figure 9.
Patient exhibiting cross-legged sitting at 6-month follow-up
Discussion
Nonoperative management of distal femur unicondylar fractures has led to unsatisfactory results. Hence, these fractures are usually treated with open reduction and internal fixation to avoid malangulation, rotation deformity, loss of knee motion, joint contracture, and posttraumatic arthritis, which was commonly associated with conservative management.[15] Open reduction helps to achieve articular congruency, rigid fixation, maintain length, alignment, and rotation, and allow early mobilization. Cannulated cancellous screw fixation being one of the most commonly used technique for unicondylar femur fractures, have an overall good results, but lack rigid fixation, hence on a long run there are cases of screw loosening and loss of articular congruity being reported, especially in osteoporotic bones[3,8] The other commonly used method of fixation is conventional locking plate, which has the disadvantage of predetermined screw trajectories, requires extensive soft-tissue dissection due to large size of implant, and also, the cost of implant is considerable.
With no specific implant design for isolated condyle fracture, the current study applied the calcaneal plate in buttress mode for medial, lateral, as well as in tangential posterior fractures of distal femur (Arbeitsgemeinschaft fur Osteosynthesefragen type 33B1, 33B2, and 33B3). Inherent design features of calcaneal D plate, which make it appropriate for fixation of isolated femoral fractures, are as follows: (a) it provides wide area of bone coverage, increasing the surface area of fixation while the spanning structural design of the construct offers regions of intermittent fixation, likely promoting periosteal preservation and ultimately fracture union[9]; (b) the plate can be used as a large washer, representing a unique management option for comminuted fracture pattern, osteoporotic or osteopenic bones[9]; (c) low profile design of the plate reduces the risk of irritation of the surrounding tissue and can be contoured as per the need of fracture pattern while maintaining the fatigue strength and durability[9]; and (d) the plate is moldable, and the presence of numerous holes in the plate enables a variety of possible fixation in comminuted fractures.
Conclusion
In conclusion, from our study, it was found that operative management with calcaneal plate in unicondylar distal femoral fractures has shown promising results with progressively better ROM of knee with subsequent follow-ups and better functional outcomes. However, though the results are internally valid, to generalize the outcome, a larger sample size and longer follow-up are required.
Ethical statement
Ethical committee approval for the study was obtained in November 2021. Approval number: 13/MC/EC/2021.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Authors contributions
All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by D.D.S., S.L.S., S.N., and A.S. K.T.V. helped in data analysis and statistical analysis of the study. The first draft of the manuscript was written by D.D.S., R.C.M., and S.N. helped in manuscript editing and manuscript review. All authors commented on previous versions of the manuscript. All authors have read and approved the final manuscript.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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