Posterior cruciate ligament injury is influenced by intercondylar shape and size of tibial eminence

The larger patellar tilt angle and lower intercondylar notch angle might increase posterior cruciate ligament injury risk: a retrospective comparative study

BACKGROUND

Posterior cruciate ligament (PCL) injuries are common ligament injuries of the knee, and previous studies often focused on the associations between the morphology of the knee and PCL injuries. Studies on the correlation between PCL injuries and patellofemoral alignment are limited.

METHODS

This retrospective study included 92 patients with PCL injured and 92 patients with PCL intact. Measurement parameters were compared between the two groups, including patellar tilt angle, congruence angle, patellar height, hip-knee-ankle angle, lateral trochlear inclination, femoral condyle ratio, bicondylar width, intercondylar notch width and index, notch angle, trochlear facet asymmetry, and trochlear sulcus depth and angle. Independent risk factors associated with PCL injuries were identified by logistic regression analyses.

RESULTS

In the PCL injured group, the patellar tilt angle was significantly larger (13.19 ± 5.90° vs. 10.02 ± 4.95°, P = 0.04); the intercondylar notch angle was significantly lower (60.97 ± 7.83° vs. 67.01 ± 6.00°, P = 0.004); the medial and lateral femoral condyle ratio were significantly larger (0.63 ± 0.64 vs. 0.60 ± 0.56, P = 0.031; 0.65 ± 0.60 vs. 0.58 ± 0.53, P = 0.005) than in the PCL intact group. There were 11 patients with patellar dislocation in the PCL injured group, accounting for 12%. In these patients, the patellar height was higher (1.39 ± 0.17 vs. 1.09 ± 0.25, P = 0.009); the trochlear sulcus angle was larger (157.70 ± 8.7° vs. 141.80 ± 8.78°, P < 0.001); and the trochlear sulcus depth was shallower (3.10 ± 1.20mm vs. 5.11 ± 1.48mm, P = 0.003) than those in the patients without patellar dislocation. Multivariate analyses showed that patellar tilt angle (each increase 1 degree, OR = 1.14) and intercondylar notch angle (each increase 1 degree, OR = 0.90) were independent risk factors for PCL injuries.

CONCLUSION

The patients with PCL injuries had larger patellar tilt angles, lower intercondylar notch angles, and longer posterior femoral condyles than patients with PCL intact. The larger patellar tilt angle and lower intercondylar notch angle might be risk factors for PCL injuries.

Parameter-based patient-specific restoration of physiological knee morphology for optimized implant design and matching

Total knee arthroplasty (TKA) patients may present with genetic deformities, such as trochlear dysplasia, or deformities related to osteoarthritis. This pathologic morphology should be corrected by TKA to compensate for related functional deficiencies. Hence, a reconstruction of an equivalent physiological knee morphology would be favorable for detailed preoperative planning and the patient-specific implant selection or design process. A parametric database of 673 knees, each described by 36 femoral parameter values, was used. Each knee was classified as pathological or physiological based on cut-off values from literature. A clinical and a mathematical classification approach were developed to distinguish between affected and unaffected parameters. Three different prediction methods were used for the restoration of physiological parameter values: regression, nearest neighbor search and artificial neural networks. Several variants of the respective prediction model were considered, such as different network architectures. Regarding all methods, the model variant chosen resulted in a prediction error below the parameters' standard deviation, while the regression yielded the lowest errors. Future analyses should consider other deformities, also of tibia and patella. Furthermore, the functional consequences of the parameter changes should be analyzed.

Increased Medial Femoral Condyle Angle and Narrow Intercondylar Notch Are Associated With Medial Meniscus Posterior Root Tear

PURPOSE

To investigate the correlation between nontraumatic medial meniscus posterior root tear (MMPRT) and bone morphology of the knee with a particular emphasis on MMPR impingement.

METHODS

Magnetic resonance imaging (MRI) findings were examined between January 2018 and December 2020. MRI findings of patients with traumatic MMPRT, Kellgren Lawrence stage 3-4 arthropathy on radiographs, single- or multiple-ligament injuries and/or those who underwent treatment for these diseases, and surgery in and around the knee were excluded from the study. MRI measurements included medial femoral condylar angle (MFCA), intercondylar distance (ICD), and intercondylar notch width (ICNW), distal/posterior medial femoral condylar offset ratio, notch shape, medial tibial slope (MTS) angle, and medial proximal tibial angle (MPTA) measurements and spur presence and were compared between groups. All measurements were performed by two board-certified orthopedic surgeons on a best agreement basis.

RESULTS

MRI examinations of patients aged 40-60 were analyzed. MRI findings were divided into two groups: the study group of MRI findings of patients with MMPRT (n = 100) and the control group of MRI findings of patients without MMPRT (n = 100). MFCA was found to be significantly higher in the study group (mean: 46.5 ± 3.58) than in the control group (mean: 40.04 ± 4.61) (P < .001). In the study group, the ICD (study group mean: 76.26 ± 4.89; control group mean: 78.18 ± 6.1) was significantly narrower (P = .018), and the ICNW (study group mean: 17.19 ± 2.23; control group mean: 20.48 ± 2.13) was significantly shorter (P < .001). The ICNW/ICD ratio was significantly lower in patients in the study group (0.22 ± 0.02) than in the control group (0.25 ± 0.02) (P < .001). Bone spurs were present in 84% of the study group and only in 28% of those in the control group. In the study group, the most common notch type was A-type with 78%, while the least common was the U-type notch with 10%. However, in the control group, the most common notch type was A-type with 43%, and the least common was the W-type notch with 22%. The distal/posterior medial femoral condylar offset ratio was statistically lower in the study group (0.72 ± 0.07) than in the control group 0.78 ± 0.07) (P < .001). No significant intergroup differences were found in MTS (study group mean: 7.51 ±2.59; control group mean: 7.83 ± 2.57) (P = .390) and MPTA (study group mean: 86.92 ±2.15; control group mean: 87.48 ±1.8) measurements (P = .67).

CONCLUSIONS

Increased medial femoral condylar angle, low distal/posterior femoral offset ratio, narrow intercondylar distance and intercondylar notch width, A-type notch shape, and spur presence are associated with MMPRT.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Decreased medial posterior tibial slope is associated with an increased risk of posterior cruciate ligament rupture

PURPOSE

It remains unclear whether there is an association between posterior cruciate ligament (PCL) rupture and the medial posterior tibial slope (MTS) or lateral posterior tibial slope (LTS). The present case-control study aimed to investigate a possible association between primary PCL rupture and MTS or LTS measured by magnetic resonance imaging (MRI).

METHODS

A retrospective case-control study was conducted. Patients with primary PCL ruptures but not with anterior cruciate ligament injuries, were 1:1 matched by age and sex to a control group with no evidence of knee ligament injuries. Knee MRI was used to measure the MTS and LTS. In addition, the receiver operating characteristic (ROC) analysis was performed to identify an optimal cut-off value of the MTS and/or LTS.

RESULTS

In total, 46 patients with PCL ruptures (32 males, 14 females) and 46 controls (32 males, 14 females) were included in this study. The MTS was significantly lower in the patients with PCL ruptures (3.0° ± 2.2°) than in the control group (5.1° ± 2.3°, p < 0.001). The mean LTS/MTS ratio was significantly higher in patients with PCL ruptures (2.6 ± 2.5) than in the control group (1.3 ± 1.3, p = 0.001). However, the LTS was not significantly different between patients with PCL ruptures and the controls (4.4° ± 2.3° vs. 5.3° ± 2.6°, n.s.). After the MTS was determined to be a significant predictor, the ROC analysis was performed. The ROC analysis revealed the most accurate MTS cut-off of < 3.9°, with a sensitivity of 76.1% and a specificity of 73.9%.

CONCLUSION

A decreased MTS and an increased LTS/MTS ratio are associated with an increased risk of primary PCL rupture. People with MTS < 3.9° are particularly at risk for PCL ruptures, and prevention and intervention programs for PCL ruptures should be developed and targeted towards them.

LEVELS OF EVIDENCE

Level III.

The effect of posterior cruciate ligament tibial avulsion fracture on functional outcomes in knees with concomitant ipsilateral lower limb fractures: a matched-cohort analysis

BACKGROUND

At present, the optimal treatment for posterior cruciate ligament tibial avulsion fracture (PCLTAF) combined with concomitant ipsilateral lower limb fractures remains unclear. The present study aimed to assess the preliminary outcomes of treatment for PCLTAF with concomitant ipsilateral lower limb fractures by open reduction and internal fixation (ORIF).

MATERIALS AND METHODS

The medical records of patients who sustained PCLTAF with concomitant ipsilateral lower limb fractures between March 2015 and February 2019 and underwent treatment at a single institution were retrospectively reviewed. Imaging examinations performed at the time of injury were applied to identify concomitant ipsilateral lower limb fractures. We used 1:2 matching between patients with PCLTAF combined with concomitant ipsilateral lower limb fractures (combined group; n = 11) and those with isolated PCLTAF (isolated group; n = 22). Outcome data were collected, including the range of motion (ROM) and visual analogue scale (VAS), Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. At the final follow-up, the clinical outcomes were compared between the combined and isolated groups and between patients who underwent early-stage surgery and those who underwent delayed treatment for PCLTAF.

RESULTS

Thirty-three patients (26 males, 7 females) were included in this study, with eleven patients having PCLTAF and concomitant ipsilateral lower limb fractures and a follow-up of 3.1 to 7.4 years (average, 4.8 years). Compared to patients in the isolated group, patients in the combined group demonstrated significantly worse Lysholm scores (85.7 ± 5.8 vs. 91.5 ± 3.9, p = 0.040), Tegner scores (4.4 ± 0.9 vs. 5.4 ± 0.8, p = 0.006), and IKDC scores (83.6 ± 9.3 vs. 90.5 ± 3.0, p = 0.008). Inferior outcomes were found in patients with delayed treatment.

CONCLUSIONS

Inferior results were found in patients with concomitant ipsilateral lower limb fractures, while better outcomes were obtained in patients with PCLTAF through early-stage ORIF using the posteromedial approach. The present findings may help determine the prognoses of patients with PCLTAF combined with concomitant ipsilateral lower limb fractures treated through early-stage ORIF.

Study of double button plate and cannulated screw fixation for posterior cruciate ligament avulsion fracture

Background

The posterior cruciate ligament (PCL) plays an important role in maintaining the stability of the knee joint. To date, researchers have not reached agreement on which type of fixation material should be used to treat PCL tibial avulsion fractures. The aim of this study was to investigate the effects of double button plate and cannulated screw fixation in the treatment of PCL avulsion fractures.

Methods

We retrospectively reviewed our database, which was collected prospectively. From January 2019 to January 2020, 46 patients with posterior cruciate ligament avulsion fractures who were treated with double button plate and cannulated screw fixation. The primary outcomes of this study were surgical complications (fixation failure/displacement, implant breakage, nonunion, infection), radiological parameters, and knee function and secondary outcomes included reoperation rates for the fixation methods and the prevalence of symptomatic hardware causing soft tissue irritation outcomes were included. Values were analysed using multiple comparisons, where P-values of 0.05 or less were considered significant.

Results

Double button plate fixation had significantly higher values than cannulated screw fixation. The results showed that double button plate fixation was related to greater decreases in the length of surgery, intraoperative blood loss, hospital days, full weight bearing time, and incidence of complications, as well as greater increases in postoperative range of motion and Knee Society Score function and Lysholm scores.

Conclusion

Compared with cannulated screw fixation, the use of double button plate fixation technology has the following advantages: less trauma, shorter operation time, convenient use of instruments and fixtures, and it does not need to be removed, thus avoiding secondary trauma. Moreover, double button plate fixation under direct vision is safe and reliable without the need for additional equipment.

Smaller intercondylar notch size and smaller ACL volume increase posterior cruciate ligament rupture risk

PURPOSE

Little is known about risk factors for sustaining a posterior cruciate ligament (PCL) rupture. Identifying risk factors is the first step in preventing a PCL rupture from occurring. The morphology of the knee in patients who ruptured their PCL may differ from that of control patients. The hypothesis was that the intercondylar notch dimensions, 3-D volumes of the intercondylar notch and, the 3-D volumes of both the ACL and the PCL were correlated to the presence of a PCL rupture.

METHODS

The magnetic resonance imaging (MRI) scans of 30 patients with a proven PCL rupture were compared to 30 matched control patients with proven intact ACL and PCL. Control patients were selected from patients with knee trauma during sports but without cruciate ligament injury. Patients have been matched for age, height, weight, BMI, and sex. The volumes of the intercondylar notch and both the ACL and PCL were measured on 3D reconstructions. Second, the bicondylar width, the notch width, and the notch width index were measured of all subjects. The relationship between our measurements and the presence of a PCL rupture was analysed.

RESULTS

The results show a significant difference in the volumes of the intercondylar notch and the ACL between patients with a ruptured PCL and control patients. Patients with a PCL rupture have smaller intercondylar notch volumes and smaller ACL volumes. There were no significant differences in the bicondylar width, notch width, and notch width index. In the control patients, a significant correlation between the volume of the PCL and the volume of the ACL was found (0.673, p < 0.001).

CONCLUSION

Patients with a PCL rupture have smaller intercondylar volumes and smaller ACL volumes when compared to control patients. Second, patients with smaller ACL volumes have smaller PCL volumes. This study shows, for the first time, that there are significant size and volume differences in the shape of the knee between patients with a PCL rupture and control patients.

LEVEL OF EVIDENCE

IV.

Morphological Risk Factors for Posterior Cruciate Ligament Tear and Tibial Avulsion Injuries of the Tibial Plateau and Femoral Condyle

BACKGROUND

Identification of morphological risk factors associated with the knee that threaten ligaments is important for understanding injury mechanisms and prevention. However, the morphological risk factors for posterior cruciate ligament (PCL) lesions are not clearly understood.

PURPOSE

To investigate whether the medial tibial depth (MTD), medial and lateral posterior tibial slope, asymmetry of the medial and lateral slopes, radius of the sagittal plane medial femoral condyle, coronal tibial slope, and notch width index (NWI) were risk factors for PCL intrasubstance tearing (PCLIT) and tibial avulsion fractures (PCLAF).

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Between January 2015 and March 2022, 82 patients with isolated PCLIT, 68 patients with isolated PCLAF, and 82 controls without any ligamentous or meniscal pathologic findings as determined via physical examination and magnetic resonance imaging were included. Values were compared among the 3 groups. Logistic regression analysis was performed to confirm the risk factors. Receiver operating characteristic curves were defined for the morphological indicators and combination of risk factors.

RESULTS

Logistic regression analysis revealed (1) MTD, lateral minus medial posterior tibial slope, radius of the posterior circle of the medial femoral condyle, and NWI as significant independent predictors for PCLIT and (2) MTD and NWI for PCLAF. The areas under the curve combining the 4 indicators for PCLIT and noncontact PCLIT were 0.79 (95% CI, 0.72-0.86) and 0.90 (95% CI, 0.85-0.96), respectively. The area under the curve for the combination of MTD and NWI for PCLAF was 0.78 (95% CI, 0.70-0.86).

CONCLUSION

Decreased MTD and NWI were associated with an increased incidence of PCLIT and PCLAF. Increased asymmetry of the medial and lateral slopes and the radius of the posterior circle of the medial femoral condyle were associated with the presence of PCLIT. In addition, the model of a combination of risk factors showed good predictive ability for noncontact PCLIT. These findings may aid clinicians in identifying patients at risk for PCL lesions. Further studies are warranted for identifying the effect of these factors on biomechanical mechanisms.

Intercondylar notch volume in patients with posterior cruciate ligament tears and tibial avulsion injuries: a study applying computed tomography

BACKGROUND

Two relatively common forms of injury exist in the posterior cruciate ligament (PCL) after the onset of trauma: PCL tear and tibial avulsion fracture. The mechanism for the occurrence of these different forms of injury is not known. Herein, we aimed to investigate this mechanism by comparing the intercondylar notch parameters between patients with PCL tears and those with PCL avulsion fractures of the tibial insertion.

METHODS

Fifty-three patients with PCL tears (37 male, 16 female: median age of 37 years: range 18-54 years) and 46 patients with avulsion fractures of tibial insertion (33 male, 13 female: median age of 33 years: range 18-55 years) were included in this study. Three-dimensional computed tomography (CT) was applied to measure the intercondylar notch width index and intercondylar notch volume. The intercondylar notch volume was simulated as the truncated-pyramid shape. Measurements of the top and bottom areas of this model were conducted on the slice containing the most proximal (S₁) and most distal (S₂) levels of Blumensaat's line. Femoral condyle height (h) was defined as the vertical distance between two parallel planes, and the volume was calculated as h(S₁ + S₂ + √(S₁S₂))/3. The values of S₁, S₂, h, notch volume, the body mass index (BMI), intercondylar notch width (NW), femoral condylar width (FW) and notch width index (NWI) were compared among the PCL tear and avulsion-fracture groups.

RESULTS

The results show a significant difference in the S₂ and normalized intercondylar notch volumes among patients with PCL tears and tibial avulsion injuries. Patients with PCL tears have smaller S₂ and intercondylar notch volumes than those with tibial avulsion. There were no significant differences between the two groups in S₁ or the 2D notch measurement parameters, such as the NW, FW and NWI. In addition, logistic regression analysis revealed notch volume and body mass index (BMI) as two significant independent predictors for PCL tears.

CONCLUSION

Decreased intercondylar notch volume and increased BMI are associated with an increased incidence of PCL tears. The occurrence of PCL tears and tibial avulsion injuries is influenced by the femoral intercondylar notch volume, and the measurement of the notch volume could be useful for identifying patients at risk for PCL tears.

Global variation in isolated posterior cruciate ligament reconstruction

Purpose

In the setting of persistent instability or failed non-operative management, surgical reconstruction is commonly recommended for isolated posterior cruciate ligament (PCL) tears. The purpose of this study was to systematically review published studies to evaluate regional variation in the epidemiology of and surgical approaches to primary, isolated PCL reconstruction.

Methods

A systematic review was performed in June 2022 to identify studies examining operative techniques during primary, isolated PCL reconstruction. Collected variables consisted of reconstruction technique, graft type, graft source, tibial reconstruction technique, femoral and tibial drilling and fixation methods, and whether the remnant PCL was preserved or debrided. Studies were classified into four global regions: Asia, Europe, North America, and South America.

Results

Forty-five studies, consisting of 1461 total patients, were identified. Most of the included studies were from Asia (69%, n = 31/45). Single bundle reconstruction was more commonly reported in studies out of Asia, Europe, and North America. Hamstring autografts were utilized in 51.7% (n = 611/1181) of patients from Asia and 60.8% (n = 124/204) of patients from Europe. Trans-tibial drilling and outside-in femoral drilling were commonly reported in all global regions. The PCL remnant was generally debrided, while remnant preservation was commonly reported in studies from Asia.

Conclusion

Surgical treatment of isolated PCL injuries varies by region, with the majority of published studies coming from Asia. Single-bundle reconstruction with hamstring autograft through a trans-tibial approach is the most commonly reported technique in the literature, with males reported to undergo isolated reconstruction more often than females.

Level of Evidence

Systematic review, Level IV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00541-4.

Relationship between the height of fibular head and the incidence and severity of knee osteoarthritis

The purpose of this study was to investigate the correlation between fibular head height and the incidence and severity of osteoarthritis associated with varus knee deformity. The fibular head height, joint line convergence angle (JLCA) and medial proximal tibial angle (MPTA) were measured in a three-dimensional model. Ordinal multivariate logistic regression was used to analyze the correlation between fibular head height and Kellgren–Lawrence (K–L) grade. Pearson correlation was used to analyze the correlation between fibular head height and K–L grade. A total of 232 patients (232 knees) were finally included in the study. There were significant differences in JLCA and hip–knee–ankle angle (P < 0.05), and both JLCA and hip–knee–ankle angle increased with severe aggravation of K–L grade. Both fibular head height and MPTA decreased as the K–L grade was severely aggravated. There was a significant negative correlation between K–L grade and fibular head height (r = −0.812, P < 0.001). Furthermore, there was a significant negative correlation between fibular head height and hip–knee–ankle angle (r = −0.7905, P < 0.001). In addition to body mass index, fibular head height is a risk factor for the pathogenesis of osteoarthritis associated with varus knee deformity; the smaller the fibular head height, the more severe the degree of varus deformity.

Decreased lateral posterior tibial slope and medial tibial depth are underlying anatomic risk factors for posterior cruciate ligament injury: a case-control study

Objectives

To research whether medial PTS, lateral PTS and MTD were different between the PCL injury group and the PCL intact group.

Design

Retrospective case–control study, level of evidence III.

Methods

Fifty patients with PCL rupture from 2015 to 2020 in our hospital, and 50 patients matched by age and sex with intact PCL were enrolled in our study. The intraclass correlation coefficient (ICC) was used to assess the reliability of each parameter. The independent t-test was conducted to identify the differences in tibial morphometric characteristics between the PCL-injured and PCL-intact individuals, including the posterior tibial slope (PTS), meniscal slope (MS), medial tibial depth (MTD). A binary logistic regression model was established to evaluate the roles of those anatomic parameters of interest play in PCL injuries.

Results

The interobserver reliability of each parameter showed excellent agreement. Significant differences in the medial (P = .023) and lateral (P = .009) PTS were found between the PCL-injured group (3.68 ± 2.70 and 4.55 ± 3.19, respectively) and the controls (5.00 ± 2.73 and 6.39 ± 3.29, respectively). And the MTD was 1.98 ± 0.64 mm in the PCL-injured group and 2.37 ± 0.55 mm in the control group (P = 0.007). Binary logistic regression analysis showed that smaller lateral PTS and MTD were directly associated with PCL injury, with an OR of 1.17 and OR of 3.14, respectively. The medial PTS was independent to PCL injures.

Conclusion

Decreased lateral PTS and MTD were underlying anatomic risk factors for PCL injury.

Patients with isolated posterior cruciate ligament rupture had a higher posterior intercondylar eminence

Background

To evaluate the anatomic geometry of the posterior intercondylar eminence and its association with PCL injury risk.

Methods

Patients who underwent primary PCL reconstruction from 2015 to 2018 were retrospectively analyzed. The control group included inpatients diagnosed with ACL rupture because of a sports-related accident during the same period, matched by age, gender, height, weight, and side of injury. Measurements of the height of the apex of the posterior intercondylar eminence (HPIE), the slope length (SLPIE) and the slope angle (SAPIE) of the posterior intercondylar eminence were performed using conventional MRI scans assessed by 2 blinded, independent raters. Intraclass correlation coefficients (ICCs) was used to evaluate the consistency of measurement results. Independent sample t tests, Chi-square tests, and logistic analyses were used to compare the two group, with P < 0.05 considered statistically significant.

Results

Fifty-five patients with PCL rupture met the inclusion criteria and 55 PCL-intact matched controls were included. There were no significant differences between the groups in gender (P = 1.000), limb side (P = 0.848), age (P = 0.291), BMI (P = 0.444) or height (P = 0.290). Inter-observer reproducibility was excellent agreement in HPIE, SLPIE and SAPIE of case and control groups (ICC: HPIE = 0.81, SLPIE = 0.77, SAPIE = 0.85). Patients with PCL rupture had significantly greater HPIE, SAPIE (both P < 0.001), and SLPIE (P < 0.05) than PCL-intact patients. The multivariable analysis showed that HPIE (OR, 1.62 [95% CI, 1.24–2.11], P < 0.001) and SAPIE (OR, 1.17 [95% CI, 1.05–1.31], P < 0.001) were independent factors associated with PCL rupture.

Conclusion

Through this retrospective observational study, we found that patients with PCL rupture may have a higher posterior intercondylar eminence compared to PCL-intact patients.

Level of evidence

III.

Stenotic intercondylar notch is not a risk factor for posterior cruciate ligament rupture: a morphological analyses using magnetic resonance imaging

PURPOSE

The present study aimed to examine the factors related to the morphological characteristics of the femoral condyle in posterior cruciate ligament rupture in female and male populations.

METHODS

One hundred and three patients (41 females, 62 males) with posterior cruciate ligament rupture from 2010 to 2020 were included in this retrospective case-control study. The sex and age of the posterior cruciate ligament rupture group were matched to those of the control group (41 females, 62 males; age range 16-69 years). Magnetic resonance imaging was used to measure the intercondylar notch width, femoral condylar width, and intercondylar notch angle in both the axial and coronal images. The 'α' angle was also measured using magnetic resonance imaging. The notch width index is the ratio of the intercondylar notch width to the femoral condylar width. Three types of intercondylar notch shapes (types A, U, and W) were evaluated in the axial magnetic resonance imaging images.

RESULTS

The difference in the mean coronal notch width index between the study groups was statistically significant in the female population. The difference in the mean coronal femoral condylar width between the study groups was statistically significant in the male population.

CONCLUSIONS

A larger coronal notch width index was the greatest risk factor for posterior cruciate ligament rupture in the female population. In the male population, decreased coronal condylar width was the greatest risk factor for posterior cruciate ligament rupture. The results did not indicate that patients with a PCL rupture have a stenotic intercondylar notch. Posterior cruciate ligament injury prevention strategies could be applied to females with a larger coronal notch width index and males with a decreased condylar width.

LEVELS OF EVIDENCE

Level III.

Isolated Partial Femoral Avulsion Fracture of the Posterior Cruciate Ligament in Adults

Objective

To investigate the manifestation, mechanisms, and treatment of isolated partial femoral avulsion fractures of the posterior cruciate ligament (PCL) in adults.

Methods

From January 2011 to December 2018, we retrospectively reviewed the clinical data of three patients with isolated partial femoral avulsion fractures of the PCL who were admitted to our institution. All of these patients were admitted to our emergency department within 24 h after injury. After physical examination and radiographs were taken and reviewed, all patients were admitted and underwent surgical treatment. In a 26‐year‐old man who underwent arthroscopic surgery through the traditional medial and lateral approach before finally converting to open surgery with the posterior approach, the fragment that was finally removed was partially attached to the PCL. In the other two patients, women aged 63 and 68 years, who underwent arthroscopic surgery via the traditional medial and lateral approach, the fragments were large and attached to most fibers of the PCL. We fixed the fragments using hollow screws in arthroscopic view. In addition, in the 63‐year‐old patient, an anchor was embedded to restore the tension of the PCL. Four weeks after surgery, the patients started to wear long leg braces in full extension with the tibia blocked up by cushion. Physical examinations were conducted and radiographs were taken preoperatively and at 4 weeks and 3 months after surgery to evaluate the condition of the injury. The range of motion and the Lysholm knee scoring scale for the knee joint were compared before and after the surgery.

Results

For the three patients, the radiographs taken at 3 months postoperatively showed that the fixation of the screws did not fail, and the subchondral bone was generally normal compared to the preoperative radiographs. CT scanning at 3 months after surgery showed that the fracture healed in the original position of the avulsion site. For all patients, the affected knees presented as stable at physical examination 3 months after surgery; the Lachmann test and the anterior drawer test results were negative. In addition, the flexion–extension, internal rotation, and external rotation were approximately 0°–130°, 0°–30°, and 0°–40° in the 26‐year‐old patient, respectively. The flexion–extension, internal rotation, and external rotation were approximately 0°–100°, 0°–20°, and 0°–35° for the 63‐year‐old patient, respectively. The flexion–extension, internal rotation, and external rotation were approximately 0°–100°, 0°–15°, and 0°–20° for the 68‐year‐old patient, respectively. There was no pain or only little pain 3 months after surgery. There was no swelling or discomfort at the 3‐month follow up. The Lysholm knee scores of the 68‐year‐old, 63‐year‐old, and 26‐year‐old patient were 80, 87, and 95 at 3 months after surgery, respectively, which were obviously improved postoperatively.

Conclusion

The manifestation of isolated partial femoral avulsion fractures of the PCL in adults is often related to the injury mechanism, and surgery is essential for the treatment of these patients. Most of these fractures can be repaired by arthroscopic surgery, but some have to be treated by open surgery.

What is the impact of knee morphology on posterior cruciate ligament avulsion fracture in men and women: a case control study

Background

Several studies on the relationship between morphological parameters and traumatic diseases of the knee have already been conducted. However, few studies focused on the association between knee morphology and posterior cruciate ligament (PCL) avulsion fracture in adults. The objective of this study was to evaluate the impact of knee morphology on PCL avulsion fracture.

Methods

76 patients (comprised 40 men and 36 women) with PCL avulsion fracture and 76 age- and sex-matched controls without PCL avulsion fracture were studied from 2012 to 2020. MRI measurements of the knee were acquired in the sagittal, coronal, and axial planes. The assessed measurements including intercondylar notch width index, coronal tibial slope, and medial/lateral posterior tibial slopes were compared between men and women, and between case and control groups respectively using independent sample t-tests. In addition, binary logistic regression analyses were used to identify independent risk factors of PCL avulsion fracture.

Results

Except notch width index (coronal) (p = 0.003) in the case groups, there was no statistical difference in the assessed measurements including notch width index (axial), coronal tibial slope, medial posterior tibial slope, and lateral posterior tibial slope between men and women in the case and control groups (p > 0.05). When female patients were analyzed, the notch width index (coronal) was significantly smaller (p = 0.0004), the medial posterior tibial slope (p = 0.018) and the lateral posterior tibial slope (p = 0.033) were significantly higher in the case group. The binary logistic regression analysis showed that the notch width index (coronal) (B = -0.347, OR = 0.707, p = 0.003) was found to be an independent factor of PCL avulsion fracture. However, none of the assessed measurements was found to have a statistical difference between the case and control groups in men (p > 0.05).

Conclusions

Notch width index (coronal), medial posterior tibial slope, and lateral posterior tibial slope were found to affect PCL avulsion fracture in women, but no such measurements affected the PCL avulsion fracture in men. Furthermore, a smaller notch width index (coronal) in women was found to be a risk factor in PCL avulsion fracture.