Residual radiographic fracture displacement in healed tibial plateau fractures: comparison after treatment with suprapatellar nailing versus lateral plating

Abstract

Objectives:

Compare maintenance of articular reduction and alignment in bicondylar tibial plateau fractures (OTA/AO 41-C2/C3) treated with suprapatellar intramedullary nailing (IMN) versus dual-plate open reduction and internal fixation (ORIF).

Design:

Retrospective Cohort Study.

Setting:

Single Level I academic trauma center.

Patients/Participants:

Fifty-eight adults treated between July 2012 and July 2022 (28 IMN, 30 ORIF); groups were matched for age, body mass index, and fracture pattern.

Intervention:

Semiextended suprapatellar IMN with ≥1 independent lag screw compared with dual-plate ORIF performed through standard open approaches.

Main Outcome Measurements:

Joint-line depression, condylar widening, medial proximal tibial angle (MPTA), and posterior proximal tibial angle (PPTA) at union (12 months).

Results:

Initial displacement was greater in the ORIF cohort (joint-line 8.2 mm vs. 5.6 mm, P = 0.014; widening 7.2 mm vs. 5.8 mm, P = 0.150). At 12 months, healed widening (0.6 mm IMN vs. 1.0 mm ORIF, P = 0.856), healed depression (2.0 mm vs. 1.1 mm, P = 0.991), MPTA (89.9° vs. 89.6°, P = 0.699), and PPTA (11.3° vs. 9.8°, P = 0.078) did not differ. No secondary loss of reduction requiring revision occurred.

Conclusion:

Suprapatellar IMN maintained healed joint line displacement, condylar widening, MPTA, and PPTA in OTA/AO C1, C2, and certain C3 fractures. The MPTA and PPTA were surgically restored and maintained. This technique may be useful in certain circumstances where ORIF of the tibial plateau fractures places the soft tissue envelope at risk or where an intramedullary implant is otherwise preferred.

Level of Evidence:

Level III.

1. Introduction

Articular fractures of the tibial plateau can be a formidable challenge for orthopaedic surgeons. They account for roughly 1% of all fractures and up to 8% in older adults,¹ frequently resulting in complex bicondylar patterns with joint depression as classified by Schatzker.² Because the proximal tibia is subcutaneous and covered by a tenuous soft-tissue envelope, every treatment decision must balance osseous reduction with soft-tissue preservation.³

Early advocates such as Koval and Helfet stressed evaluating both the “personality” of the fracture and the surrounding soft-tissue before choosing fixation.⁴ High-energy mechanisms often produce significant concomitant soft-tissue injury,^5,6 and subsequent healing, infection risk, and long-term outcomes hinge on the viability of that tissue.⁷ Accordingly, displaced plateau fractures are traditionally managed by staged external fixation followed by open reduction and internal fixation (ORIF) with dual plates.^8–10

Although ORIF can achieve anatomical restoration, plate application requires extensive periosteal stripping and may further compromise already injured soft tissue.¹¹ Intramedullary nailing (IMN) offers a biologic, load-sharing alternative that minimizes additional dissection while preserving endosteal blood supply.^12–14 Initially limited to diaphyseal fractures, IMN has since been described for intra-articular distal tibia and selected tibial plateau fractures.^15–17 Traditional infrapatellar nailing of the proximal tibia is technically demanding and prone to malalignment¹⁸; however, the suprapatellar semiextended approach realigns the entry trajectory with the medullary canal, expanding indications proximally and distally.^12,19

Biomechanical investigations comparing IMN, dual-plate ORIF, and external fixation for bicondylar plateau fractures show that IMN constructs withstand higher loads to failure and generate faster callus without loss of reduction.^20–22 Clinically, suprapatellar IMN has demonstrated comparable union rates, acceptable sagittal and coronal alignment, and low complication profiles in both extra-articular and simple intra-articular patterns.^23,24 These attributes make IMN particularly attractive for combined intra-articular and meta-diaphyseal fractures (OTA/AO 41-C1, 41-C2, and selected 41-C3) in which soft-tissue compromise or fracture morphology renders plating less desirable.

The purpose of this study was to compare postoperative maintenance of articular reduction, coronal alignment (medial proximal tibial angle [MPTA]), and sagittal alignment (posterior proximal tibial angle [PPTA]) in bicondylar tibial plateau fractures treated with suprapatellar IMN versus dual-plate ORIF and to identify fracture patterns best suited for IMN fixation.

2. Methods

From July 2012 to July 2022, 58 patients with C2 and C3 bicondylar tibial plateau fractures were treated with either IMN or ORIF at a Level 1 trauma center. Before beginning the study, an institutional review board approval was obtained to review patient charts and imaging. The study group included 28 patients treated with suprapatellar IMN in the semiextended position, with 30 patients treated with ORIF, serving as a comparison group. No patients in either group were converted intraoperatively to the other group. In addition, any mixed constructs were excluded from the study.

The groups were matched based on age, sex, body mass index (BMI), comorbidities, injury mechanism, OTA/AO fracture pattern and classification, presence of open fracture, treatment with decompressive fasciotomy, initial immobilization with an external fixator, and treated by the same surgeon. The IMN technique described was used at the discretion of the treating surgeon based on the previously discussed rationale for IMN of tibial plateau fractures. The amount of initial depression was not used in the selection process.

All patient imaging was reviewed and correlated with clinical encounter notes. Technique for measuring radiographs is described in a separate section below. Patients' charts were reviewed for range of motion (ROM) at the 1-year follow-up. As part of standard documentation, for patients who have ≥90° ROM, the precise ROM is not documented when the patient is not enrolled in a prospective clinical research project. Since the data were gathered retrospectively, obtaining exact ROM was not possible in these cases. Patient encounter notes were evaluated to determine time to weight bearing as tolerated (WBAT) after the date of definitive fixation. Time to weight bearing was rounded to the nearest week (ie,: 11 weeks and 3 days after surgery was reported as 11 weeks). Clinical notes and operative reports were reviewed to identify open fractures, mechanism of injury, staged treatment using external fixator (ExFix), or fasciotomy.

2.1. Surgical Techniques

2.1.1. Intramedullary Nailing

Patients were positioned supine with the knee semiextended on a foam ramp. A suprapatellar portal was used to align the entry point with the medullary canal. After provisional reduction with percutaneous joysticks or clamps, 1–2 independent 6.5-mm lag screws were inserted to stabilize the articular block. A reamed tibial nail offering up to 4 fixed-angle proximal locking options was then inserted; a mean of 3 proximal interlocking screws were used. No bone graft or substitute was required in this series (Fig. 1).

Figure 1.

A 27-year-old man struck by a motor vehicle. CT 3D reconstruction and AP view demonstrates a bicondylar tibial plateau fracture along with tibial shaft (A–C). Two 6.5-mm screws were passed to compress the articular block away from nail entry and set up for a standard IMN (D, E). The 13-month follow-up demonstrating adequate bone healing and maintained alignment on anterior-posterior and lateral radiographs with measurement of alignment (F, G).

2.1.2. Open Reduction and Internal Fixation

Dual plating was performed through an anterolateral and a posteromedial (or medial) approach. Articular surface was elevated with tamps as needed and supported by subchondral rafting screws. Voids >5 mm were filled with injectable calcium-phosphate bone substitute. Plates were applied in compression mode to restore both columns before metaphyseal locking screws were added.

Postoperatively all patients commenced unrestricted passive knee motion on day 1; partial weight bearing was permitted once pain tolerated and radiographic alignment was confirmed.

2.2. Measurement of Radiographic Outcomes

Two independent reviewers assessed plain radiographs for fracture displacement and the corresponding clinical charts for knee ROM and weight bearing status. To minimize observational bias, (1) images were viewed in random order such that no patient's sequential films were assessed consecutively and (2) the operating surgeons did not perform any measurements. Displacement and reduction quality were recorded using a previously described technique.²²

This study focused on how the reduction held over time, and therefore, if the measurement technique was consistent over time, the absolute change measured would also be consistent. The authors accounted for the normal relationship of the tibial condyle and femoral epicondyle, as described by previous authors.^22,23 Widening was defined as the sum of medial and lateral displacement in millimeters, measured between these 2 lines.^22,23 (Fig. 2C) Joint line depression was defined as a line from where it was determined the joint line needed to be and a second line based on displacement from that line. A second measurement was taken of the same fragment spike and the correlating defect on the intact tibia (Fig. 2B). Those measurements were then averaged. Initial preoperative CT scans were available for all patients and were correlated with preoperative plain radiographs to define the largest weight bearing articular fragment and to confirm X-ray measured displacement.

Figure 2.

A 90-year-old woman, external fixator from an outside surgeon, with significant soft-tissue swelling and blistering. (A) CT 3D reconstruction demonstrates a bicondylar tibial plateau fracture. (B) Demonstrated measurement of initial joint line depression. (C) Measurement of condylar widening. (D–F) The screw guide pin is placed and used to manipulate articular block in the varus valgus plane. Two 6.5-mm screws were passed to compress the articular block and set up for a standard IMN. (G–J) The 17-month follow-up demonstrating bone healing and sagittal and coronal medial proximal tibial angle (MPTA) measurement technique on anterior-posterior and lateral radiographs.

Coronal and sagittal alignment was measured with a line parallel to the joint surface, with a second line down the tibial shaft previously described in the literature.²⁴ This was measured on postoperative images using full-length X-rays (Fig. 2I and J), or if full-length was unavailable, the anterior and posterior cortex was used to calculate anatomical midline (Fig. 3E and F).

Figure 3.

A 49-year-old male pedestrian versus MVC. (A–D) CT and X-rays demonstrating a C3 tibial plateau fracture with joint depression; (E and F) postoperative placement of the 6.5-mm screw, which allows a routine starting point for IMN. (E and F) 12-month healing X-ray with MPTA and sagittal measurement technique for assessment of axial alignment at healing.

The MPTA and PPTA were measured according to established definitions (Table 1). MPTA is the medial angle formed between the tibial articular margin and the mechanical axis on an anteroposterior radiograph (normal 85–90°). PPTA is the angle between the tibial mechanical axis and the proximal tibial joint line on a true lateral radiograph (normal 77–84°).^22,25,26

Table 1.

Combined data table (IMN vs. ORIF; MPTA and PPTA).

IMN MPTA (°)	IMN Relative MPTA (°) (Rel. to 87°)	ORIF MPTA (°)	ORIF Relative MPTA (°) (Rel. to 87°)	IMN PPTA (°)	IMN Relative PPTA (°) (Rel. to 90°)	ORIF PPTA (°)	ORIF Relative PPTA (°) (Rel. to 90°)
86	1	86	1	78	12	82	8
87	0	87	0	81	9	77	13
88	−1	88	−1	76	14	76	14
91	−4	90	−3	78	12	80	10
91	−4	90	−3	82	8	81	9
89	−2	90	−3	75	15	76	14
90	−3	90	−3	86	4	88	2
91	−4	90	−3	81	9	78	12
87	0	92	−5	80	10	82	8
88	−1	91	−4	80	10	82	8
86	1	86	1	79	11	83	7
90	−3	87	0	78	12	83	7
88	−1	88	−1	77	13	79	11
94	−7	90	−3	78	12	82	8
91	−4	90	−3	78	12	76	14
91	−4	90	−3	76	14	80	10
91	−4	90	−3	82	8	82	8
89	−2	90	−3	75	15	76	14
87	0	92	−5	77	13	78	12
90	−3	91	−4	81	9	82	8
91	−4	85	2	80	10	81	9
88	−1	87	0	78	12	81	9
90	−3	88	−1	77	13	81	9
91	−4	90	−3	76	14	81	9
90	−3	90	−3	80	10	82	8
91	−4	90	−3	77	13	77	13
104	−17	90	−3	77	13	77	13
87	0	97	−10	81	9	81	9
		92	−5			76	14
		91	−4			86	4

Averages—IMN MPTA: 89.9°; IMN Relative MPTA: −2.9°; ORIF MPTA: 89.6°; ORIF Relative MPTA: −2.6°; IMN PPTA: 11.3°; IMN Relative PPTA: 11.3°; ORIF PPTA: 80.2°; ORIF Relative PPTA: 9.8°.

MPTA, medial proximal tibial angle; PPTA, posterior proximal tibial angle.

2.3. Analytic Strategy

MPTA and PPTA values were compared between the IMN and ORIF group. Two samples t-tests were used to assess significance differences for these outcomes. The final healed values in MPTA and PPTA were also plotted against standard value ranges from the literature.

Changes in displacement and change in condylar widening were assessed by computing the difference between these measurements at each follow-up time point (2 months, 6 months, and 12 months) and the corresponding baseline measurement. Group differences between IMN and ORIF groups were then assessed on 2 dimensions for each measurement at each time point: the absolute mean value and the mean change over time. Independent samples t-tests were used to assess significance differences for these outcomes between IMN and ORIF groups. Group differences in time-to-recover ROM and weight-bearing activities (WBAT) were also assessed using independent samples t-tests.

A multiple linear regression analysis was conducted for all outcome variables to assess the significance of treatment group differences after controlling for baseline demographic and clinical covariates (sex, age, BMI, comorbidities, initial displacement, and initial condylar widening). Baseline demographic and clinical differences between groups were assessed using chi-square tests or independent samples t-tests, as appropriate. All analyses were conducted using SAS 9.4.

3. Results

3.1. Demographics

A total of 58 patients (28 IMN, 30 ORIF) who sustained a tibial plateau fracture with a minimum of 2 months follow-up were included in the current analysis, with an average follow-up time of 14.8 months (IMN: 21.3 vs. ORIF: 8.8 P = 0.016). Patient demographics and clinical characteristics are described in Table 2. There were differences between groups in proportion of open fractures, sex distribution, and follow-up duration: IMN patients were more often male, sustained a higher proportion of open fractures, and had a longer mean follow-up period. There were no significant differences with respect to age, race, comorbidities (smoking, diabetes, osteoporosis), fracture OTA/AO classification, laterality, initial stabilization with external fixator, or decompressive fasciotomies.

Table 2.

Baseline demographic and clinical characteristics by surgery type.

	Total (N = 58)	IMN (N = 28)	ORIF (N = 30)	P
Age, y, mean (SD)	55.6 (12.8)	56.5 (13.1)	54.7 (12.7)	0.605
Sex				0.024
Female, N (%)	21 (36.2%)	6 (21.4%)	15 (50.0%)
Male, N (%)	37 (63.8%)	22 (78.6%)	15 (50.0%)
Race				0.201
Asian, N (%)	1 (1.7%)	0 (0.0%)	1 (3.3%)
Black, N (%)	34 (58.6%)	20 (71.4%)	14 (46.7%)
White, N (%)	22 (37.9%)	8 (28.6%)	14 (46.7%)
Unknown, N (%)	1 (1.7%)	0 (0.0%)	1 (3.3%)
BMI, mean (SD)	30.8 (9.0)	28.5 (8.5)	32.9 (9.2)	0.066
Comorbidities
Smoking, N (%)	25 (43.1%)	14 (50.05%)	11 (36.7%)	0.306
Diabetes, N (%)	11 (19.0%)	7 (25.0%)	4 (13.3%)	0.257
Osteoporosis, N (%)	2 (3.4%)	1 (3.6%)	1 (3.3%)	0.960
OTA/AO classification				0.905
41 C2, N (%)	17 (29.3%)	8 (28.6%)	9 (30.0%)
41 C3, N (%)	41 (70.7%)	20 (71.4%)	21 (70.0%)
Laterality				0.293
Left, N (%)	34 (58.6%)	14 (50.0%)	20 (66.7%)
Right, N (%)	22 (37.9%)	13 (46.4%)	9 (30.0%)
Bilateral, N (%)	1 (1.7%)	0 (0.0%)	1 (3.3%)
Unspecified, N (%)	1 (1.7%)	1 (3.6%)	0 (0.0%)
Open fracture				0.006
Closed, N (%)	46 (79.3%)	18 (64.3%)	28 (93.3%)
Open, N (%)	12 (20.7%)	10 (35.7%)	2 (6.7%)
External fixator, N (%)	26 (44.8%)	13 (46.4%)	13 (43.3%)	0.813
Fasciotomy, N (%)	14 (24.1%)	8 (28.6%)	6 (20.0%)	0.446
Follow-up time, mo, mean (SD)	14.8 (19.8)	21.4 (26.4)	8.8 (7.6)	0.016

Bold values indicate P < 0.05.

Comparative statistics for tibial plateau fracture displacement at initial imaging, immediately postoperatively at 2 months (N = 58; IMN = 28, ORIF = 30), 6 months (N = 45; IMN = 22, ORIF = 23), and 12 months postoperatively (N = 32; IMN = 18, ORIF = 14) are presented in Tables 3 and 4. Clinical follow-up data are presented Table 5.

Table 3.

Joint line displacement by treatment group.

	IMN mm (SD)	ORIF mm (SD)	P	Adjusted P
Initial displacement	5.6 (3.4)	8.2 (6.1)	0.054	0.014
Immediate postoperative displacement	0.5 (0.8)	1.0 (1.4)	0.128	0.784
2 mo (n)	28 (90.3%)	30 (93.8%)	0.615
Absolute displacement	0.5 (0.8)	1.0 (1.5)	0.095	0.164
Change from previous	0.0 (0.0)	0.07 (0.3)	0.170	0.117
6 mo (n)	22 (71.0%)	23 (71.9%)	0.937
Absolute displacement	0.5 (0.8)	1.1 (1.5)	0.118	0.339
Change from previous	0.0 (0.0)	0.3 (0.5)	0.531	0.623
12 mo (n)	18 (53.1%)	14 (43.8%)	0.256
Absolute displacement	0.6 (0.8)	1.1 (1.5)	0.216	0.991
Change from previous	0.06 (0.2)	0.07 (1.4)	0.963	0.577

Adjusted P-values represent P-values for the treatment group (IMN vs. ORIF) parameter estimate from a multiple linear regression model for the corresponding outcome variable, controlling for patient sex, age, BMI, comorbidities (smoking, diabetes, osteoarthritis), initial joint line displacement, and initial condylar widening.

Table 4.

Condylar widening by treatment group.

	IMN mm (SD)	ORIF mm (SD)	P	Adjusted P
Initial displacement	5.8 (7.0)	7.2 (7.1)	0.461	0.150
Immediate postoperative	0.4 (0.8)	0.2 (0.9)	0.578
2 mo (n)	28 (90.3%)	30 (93.8%)	0.615	0.382
Absolute displacement	0.4 (0.8)	0.4 (1.0)	0.968	0.557
Change from previous	0 (0.0)	0.1 (0.5)	0.170	0.571
6 mo (n)	22 (71.0%)	23 (71.9%)	0.937
Absolute displacement	0.6 (1.6)	0.3 (1.1)	0.424	0.120
Change from previous	0.2 (1.1)	0.1 (0.5)	0.692	0.112
12 mo (n)	18 (53.1%)	14 (43.8%)	0.256
Absolute displacement	0.6 (1.7)	1.0 (2.7)	0.620	0.856
Change from previous	0.3 (1.2)	0.7 (1.7)	0.395	0.653

Adjusted P-values represent P-values for the treatment group (IMN vs. ORIF) parameter estimate from a multiple linear regression model for the corresponding outcome variable, controlling for patient sex, age, BMI, comorbidities (smoking, diabetes, osteoarthritis), initial joint line displacement, and initial condylar widening.

Table 5.

Clinical outcomes by treatment group.

	IMN	ORIF	P	Adjusted P
Time to WBAT, wk, mean (SD)	10.3 (3.1)	10.3 (2.0)	0.985	0.798
Time to ROM (>90), wk, mean (SD)	13.7 (10.3)	10.2 (6.3)	0.195	0.526

Patients with less than 6 months of follow-up time were excluded from these analyses. The number of valid time to WBAT values was 21 IMN patients and 23 ORIF patients. The number of valid time to ROM values was 21 IMN patients and 21 ORIF patients. Patients without valid outcomes either did not reach the end point by the end of the study or did not have an outcome value that could be located in patient records. Adjusted P-values represent P-values for the treatment group (IMN vs. ORIF) parameter estimate from a multiple linear regression model for the corresponding outcome variable, controlling for patient sex, age, BMI, comorbidities (smoking, diabetes, osteoarthritis), initial joint line displacement, and initial condylar widening.

3.2. Joint Line Displacement

Initial, immediate postoperative, and 12-month joint line displacement of the IMN group was 5.6 mm, 0.5 mm, and 0.6 mm. Initial, immediate postoperative and 12-month joint line displacement of the ORIF group was 8.2 mm, 1.0 mm, and 1.1 mm (Table 3). ORIF patients had a greater initial mean joint line displacement (8.2 mm) when compared with IMN patients (5.6 mm) (P = 0.014). Both groups demonstrated joint line subsidence across all postoperative measurements; however, there was no difference between the groups at all time points. Similarly, the absolute displacement was not statistically significant between the 2 groups across all time points. Joint line displacement at the final 12-month follow-up was 0.6 mm and 0.7 mm for the IMN and ORIF groups (P = 0.577).

3.3. Condylar Widening

Initial, immediate postoperative, and 12-month condylar widening of the IMN group was 5.8 mm, 0.4 mm, and 0.6 mm. Initial, immediate postoperative, and 12-month condylar widening of the ORIF group was 7.2 mm, 0.2 mm, and 1.0 mm (Table 4). ORIF patients had a greater mean condylar widening (7.2 mm) when compared with IMN patients (5.8 mm); however, this did not reach statistical significance (P = 0.150). Both groups demonstrated condylar widening across all postoperative measurements, with no difference between the groups at any time point. Similarly, the absolute displacement was not statistically significant between the 2 groups across all time points. Condylar widening at final 12-month follow-up was 0.3 mm and 0.7 mm for the IMN and ORIF groups (P = 0.653). Condylar widening and displacement over time demonstrated similar results for both modes of fixation (Fig. 4).

Figure 4.

Condylar widening and articular subsidence measured from initial injury films throughout postoperative follow-up for (1) ORIF group and (2) IMN group. PO, postoperative.

3.4. Coronal and Sagittal Alignment

The final healed MPTA for the IMN versus ORIF was 89.9° versus 89.6° (P = 0.699). The final healed PPTA for the IMN versus ORIF was 11.3° versus 9.8° (P = 0.078).

The final healed values in MPTA and PPTA were plotted against standard values from the literature. Individual final healed values for the 4 groups included MPTA for the IMN group, MPTA for the ORIF group, PPTA for the IMN group, and PPTA for the ORIF group (Figs. 5 and 6)

Figure 5.

Distribution of MPTA values for both IMN and ORIF groups relative to the normal range (85°–90°), highlighted in green.

Figure 6.

Distribution of PPTA values for both IMN and ORIF groups relative to the normal range (77°–84°), highlighted in green.

The published normal ranges for PPTA of 6–13° were used for defining normal posterior slope. The normal range for MTPA of 85–90° was used for defining normal coronal alignment.^22,25,26

3.5. Complications

Surgical complications were noted in both groups (Table 6). There were 2 superficial infections in the plate group treated with oral antibiotics. There was one case of infection in the nail group which was deep and that patient also developed a delayed union. The patient originally had a 3B open shaft plateau injury with rotational flap coverage. One patient in the nail group had an above knee amputation after a vascular bypass graft failed. The 3 hardware removal patients had their hardware removed electively.

Table 6.

Reoperations in the IMN and ORIF groups.

IMN	ORIF
Above knee amputation	1 hardware removal
1 delayed wound closure	1 MUA
1 MUA
2 hardware removals
Delayed union

4. Discussion

Currently, the prevailing surgical treatment for tibial shaft fractures in adults is intramedullary nail fixation, whereas tibial plateau fractures are approached through ORIF using a combination of plates and screws, and in many cases, nonoperative management of a minimally displaced plateau fracture is still recommended.^27–30 Because step-off tolerance and its long-term implications remain debated, the optimal construct to maintain an articular reduction is still unsettled, and the role of IMN in this setting is poorly defined.

4.1. Clinical Data

One hesitation regarding the use of an IMN in tibial plateau fractures is the construct's ability to maintain reduction in displaced tibial plateau fractures. Similar studies have focused mainly on extra-articular or low-energy injuries. A prospective pilot study by Garnavos et al¹⁵ reported reliable union and ≥90° knee flexion in 8 “fragile” patients with AO-41A fractures (mean age 67 years). Other groups have shown similarly favorable results for extra-articular tibial plateau fractures treated with nails.^31–33 Padubidri et al³⁴ compared simple intra-articular (C1/C2) and extra-articular (A1/A2) fractures and found no difference in reoperation, infection, nonunion, or mal-union between IMN cohorts. Peng et al extended these observations to 19 AO-B/C fractures, achieving union at 15 weeks with mean postoperative flexion of 123°.³² Our series adds 28 bicondylar C2/C3 fractures—many high-energy and open—to this growing body of evidence, demonstrating that a suprapatellar nail can preserve reduction as effectively as ORIF at 1 year.

4.2. Biomechanical Data

In a type VI Schatzker model, Lasanianos et al³⁵ found that an IM nail augmented with compression bolts was as stiff as dual plating and out-performed a single lateral locking plate under cyclic loading. Högel et al²⁰ demonstrated that, in a cadaveric AO-41 C2 fracture model created by osteotomy, an IM nail augmented with 2 cannulated screws withstood failure loads equivalent to those of a dual-plate construct. These studies explain our clinical observation that nail constructs resisted secondary displacement despite higher energy injury patterns.

4.3. Alternative Fixation in Compromised Bone

Circular frames are sometimes chosen for osteoporotic plateau fractures in the elderly, yet meta-analysis shows higher infection and mal-union rates compared with ORIF.³⁶ Pin-tract infection occurs in about 13% of Ilizarov applications.³⁷ These data suggest that IMN, with or without percutaneous screws, offers a soft-tissue sparing option that avoids frame-related morbidity.

4.4. Clinical Importance of Articular Displacement and Limb Alignment

Multiple studies have shown that patients who sustain a tibial plateau fracture are predisposed to post-traumatic osteoarthritis, and that the degree of articular disruption is a key driver of this risk.^38–40 Several studies have confirmed poor function outcomes with postoperative fracture displacement of >2 mm.^24,38,40,41 Assink et al strengthened this observation showing increased rates of conversion to total knee arthroplasty (TKA) when either joint-line depression or condylar widening exceeded 4 mm and suggested this wider cutoff as a pragmatic upper limit.^22,42

In the present series, the ORIF cohort began with greater mean depression (8.2 mm) and widening (7.2 mm) than the IMN cohort (5.6 mm and 5.8 mm, respectively). Despite this, both groups healed with mean depression <1 mm and widening <1 mm, well below the most conservative 2 mm threshold and far beneath Assink's 4-mm TKA trigger. These data indicate that a nail-and-screw construct can hold an adequate reduction even after high-energy bicondylar injuries.

4.5. Sagittal Plane (PPTA)

PPTA is seldom reported but strongly influences contact mechanics. Streubel et al⁴³ documented an average 9.8° posterior slope after ORIF of bicondylar fractures and warned that excessive sagittal malalignment may accelerate cartilage wear. Recent studies have identified a “safe window” of 4°–14° posterior slope; knees outside this range had higher odds of late arthroplasty.^22,24 Our final PPTA averaged 11.9° (IMN) and 9.5° (ORIF), with only one patient per cohort falling outside the protective band, suggesting both constructs can reliably restore and maintain sagittal alignment.

4.6. Coronal Plane (MPTA)

Malalignment in varus or valgus shifts load distribution and correlates with inferior outcomes. Lee et al²⁶ reported worse functional scores with any degree of residual varus and with >5° valgus after bicondylar plateau fractures. We found that in our study, coronal plane alignment (MPTA) was achieved and maintained in most patients (Fig. 5). The lone outlier (104°, 14° valgus) declined revision. This is an area that must not be ignored when operating on these fractures.

4.7. Study Limitations And Strengths

This study has weaknesses that must be considered. First, as a retrospective cohort, selection bias is unavoidable. Patients were allocated at the discretion of the surgeon based on fracture morphology, soft-tissue status, comorbidities, and surgeon preference. Consequently, two distinct selection biases emerged. (1) Open-fracture bias. The IMN cohort contained a significantly larger proportion of open injuries (35.7% vs. 6.7%, P = 0.006), suggesting that high-energy fractures with potential soft-tissue compromise were preferentially managed with intramedullary fixation. (2) Fracture-pattern bias. By contrast, the ORIF cohort showed significantly greater initial joint depression and condylar widening, reflecting a tendency to reserve ORIF for the more complex articular disruptions. This deliberate avoidance of substantial joint depression when choosing IMN narrows the generalizability of our findings and may confound comparisons of early displacement between groups. Because neither bias can be completely adjusted for in a retrospective design, caution is warranted when interpreting radiographic outcomes.

Second, follow-up was limited. The 12-month follow-up rates were 53% (IMN) and 44% (ORIF). Although comparable with rates reported in orthopaedic trauma series, the precise impact of attrition remains unknown. The longer mean follow-up in the IMN group (21.4 months) versus the ORIF group (8.8 months) likely reflects the higher incidence of polytrauma in the IMN cohort (32% vs. 16.7%), necessitating prolonged clinical surveillance.

Third, imaging modality was restricted. Postoperative CT might have improved accuracy of articular measurements; however, recent literature supports the prognostic value of plain-film assessments of axial alignment, step-off, and condylar widening alone in predicting conversion to total knee arthroplasty after tibial-plateau fractures.^22,23

A key strength of this study is that, after multivariable adjustment for sex, age, smoking, diabetes, and BMI, the ORIF group still demonstrated greater initial joint line displacement without a corresponding increase in condylar widening, and both cohorts maintained comparable final alignment at union. A trend toward increased posterior slope (PPTA) loss in the IMN cohort did not reach statistical significance.

Overall, our findings indicate that intramedullary nailing can achieve and maintain reductions equivalent to ORIF for select OTA/AO C2/C3 tibial-plateau fractures. Despite higher-energy mechanisms, greater soft-tissue compromise, and more frequent polytrauma in the IMN group, radiographic and clinical outcomes remained comparable. In carefully selected patients, IMN offers the biological and soft-tissue preservation advantages of a minimally invasive approach without sacrificing construct stability.

5. Conclusion

Suprapatellar IMN maintained articular reduction and coronal-sagittal alignment (joint-line depression, condylar widening, MPTA, and PPTA) as effectively as dual-plate ORIF in bicondylar tibial plateau fractures. Although the ORIF cohort began with significantly greater initial displacement, both groups healed with mean depression <1 mm, widening <1 mm, and final MPTA and PPTA values within accepted normal ranges. Clinical recovery was likewise comparable: mean knee flexion exceeded 90° in all documented cases and time to weight bearing as tolerated did not differ significantly between groups. These findings support IMN as a viable alternative to ORIF for selected OTA/AO 41-C2/C3 fractures while underscoring the need for prospective studies to confirm equivalence in more severely depressed patterns and to evaluate long-term functional outcomes.