An in-vitro three-dimensional surgical simulation technique to predict tibial tunnel length in transtibial posterior cruciate ligament reconstruction.

BACKGROUND: During the transtibial posterior cruciate ligament (PCL) reconstruction, drilling depth excessively longer than the tibial tunnel length (TTL) is an important reason to cause popliteal neurovascular bundle injury when preparing the tibial tunnel. This study aims to develop an in-vitro three-dimensional surgical simulation technique to determine the TTL in anteromedial (AM) and anterolateral (AL) approaches. METHODS: A total of 63 knees' 3-dimensional (3D) computed tomography models were included in this study. The SuperImage system was used to reconstruct the 3D knee model and locate the tibial PCL site. The established 3D knee model and the coordinates of the tibial PCL site were imported into Rhinoceros 3D modeling software to simulate AM and AL tibial tunnel approaches with different tibial tunnel angles (TTA). The TTL and the tibial tunnel height (TTH) were measured in this study. RESULTS: In AM and AL tibial tunnel approaches, the TTL showed a strong correlation with the TTA (for AM: r = 0.758, p < 0.001; for AL: r = 0.727, p < 0.001). The best fit equation to calculate the TTL based on the TTA was Y = 1.04X + 14.96 for males in AM approach, Y = 0.93X + 17.76 for males in AL approach, Y = 0.92X + 14.4 for females in AM approach, and Y = 0.94X + 10.5 for females in AL approach. CONCLUSION: Marking the TTL on the guide pin or reamer could help to avoid the drill bit over-penetrated into the popliteal space to damage the neurovascular structure.

Unicompartmental knee arthroplasty combined with posterior cruciate ligament reconstruction: a case report.

BACKGROUND: In this study, we present the unique case of a patient with knee osteoarthritis (OA) of the medial compartment and posterior cruciate ligament (PCL) deficiency who underwent simultaneous medial unicompartmental knee arthroplasty (UKA) and PCL reconstruction. CASE PRESENTATION: A 49-year-old male patient presented with a 1-year history of pain and instability in the left knee. The patient had previously experienced a trauma-related injury to the PCL of the left knee that was left untreated. Imaging and physical examination confirmed the presence of left medial knee OA along with PCL rupture. To address these issues, the patient underwent UKA combined with PCL reconstruction. The patient's Lysholm score was 47 before surgery and 81 three months after surgery, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 29 before surgery and 18 three months after surgery, and the International Knee Documentation Committee (IKDC) subjective score was 56.3 before surgery and 74.7 three months after surgery. Six months after surgery, the patient's gait returned to normal, and he was able to jog. CONCLUSION: This case report presents the first instance of UKA combined with PCL reconstruction and introduces a novel treatment approach for patients suffering from medial knee OA and ligament injury.

The Integral Role of Physiotherapy in Combined Complete Anterior Cruciate Ligament and Posterior Cruciate Ligament Arthroscopic Reconstruction: A Case Report.

Combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries are infrequent in clinical practice, often leading to severe knee instability and functional limitations. A 30-year-old male presented with right knee pain and swelling following a two-wheeler accident. Diagnostic investigations confirmed complete ACL and PCL tears. The surgical intervention comprised arthroscopic-assisted ACL reconstruction using semitendinosus and gracilis tendons, accompanied by arthroscopic PCL reconstruction. Postoperatively, structured physiotherapy rehabilitation was initiated. After 12 weeks of rehabilitation, significant improvements in range of motion and muscular strength were observed. Tailored physiotherapy facilitated prompt recovery, enhancing functional mobility and independent ambulation. This case highlights the efficacy of comprehensive surgical intervention followed by structured rehabilitation in achieving favorable outcomes in patients with combined ACL and PCL injuries. Tailored physiotherapy plays a crucial role in optimizing functional recovery and facilitates the enhancement of the patient's functional mobility and independent ambulation.

The tibial capsular reflection and septum in posterior compartment are safe and reliable soft-tissue landmark for tibial tunnel drilling in posterior cruciate ligament reconstruction.

PURPOSE: To investigate the validity of using tibial capsular reflection and septum in the posterior compartment as landmark during posterior cruciate ligament (PCL) reconstruction (PCLR). METHODS: Anatomic measurements were obtained for 12 fresh human cadaveric knee specimens to observe the spatial position of the tibial insertion of the PCL in relation to the posterior septum and the capsular reflection in the posterior compartment. Sixty patients who underwent reconstruction of the PCL between 2020 and 2023 were also retrospectively investigated. The tibial tunnel was replaced in all patients using the same method (with reference to the tibial capsular reflection and the posterior septum). The placement of the tibial tunnel was assessed using X-ray fluoroscopy intraoperatively and computed tomography and three-dimensional reconstruction postoperatively. RESULTS: All fibres in the tibial insertion of the PCL in the 12 cadaveric specimens were located in the posteromedial compartment, adjacent to the posterior septum. The inferior border of the PCL insertion is adjacent to the tibial capsular reflection, which is attached at the champagne glass drop-off of the posterior tibia. In our previous cases, none of the patients experienced postoperative or intraoperative complications such as neurovascular injury, and the angle between the pin and the PCL facet was 93.1 ± 3.9° as measured on intraoperative radiographs. The mean distance from the centre of the tibial tunnel outlet to the inferior border of the PCL insertion was 5.6 ± 1.1 mm, and the distance from the centre of the tibial tunnel outlet to the outer border of the PCL insertion as a percentage of the length of the inferior border of PCL insertion was 42.2 ± 6.3%. CONCLUSION: The tibial capsular reflection and septum in the posterior compartment are safe and reliable soft-tissue landmark for tibial tunnel drilling in PCLR. LEVEL OF EVIDENCE: Level Ⅳ.

Clinical and Functional Results Following Posterior Cruciate Ligament Reconstruction in Young Patients.

INTRODUCTION:  Posterior cruciate ligament injuries are uncommon, and their management is controversial. However, surgical reconstruction is necessary in case of symptomatic lesions. The present study aimed to analyse patients' reported outcomes and clinical evaluation after isolated posterior cruciate ligament reconstruction. MATERIALS AND METHODS:  The present study includes 12 patients with posterior cruciate ligament rupture. All patients were treated with arthroscopic surgery using single-bundle hamstring autograft ligament reconstruction. The primary outcome was the International Knee Documentation Committee (IKDC) subjective questionnaire; secondary outcomes included the Lysholm score and stability assessment.  Results: At the time of the surgery, the mean age of the study population was 24 years (range: 18-29), with a body mass index (BMI) of 23.2 kg/m2 (range: 21-25), and the mean time from injury was five months (range: 1-8). The follow-up period was at least 24 months. The mean IKDC score significantly increased from 68.0 preoperatively to 92.6 at the final follow-up. The Lysholm score also increased from 68.8 to 95.8. Knee stability was classified as normal in all patients after surgery. CONCLUSION:  The results of this study indicate that the posterior cruciate ligament reconstruction with single-bundle hamstring autograft is an efficient treatment option for managing symptomatic young patients. All patients presented good functional and clinical results at two years of follow-up. However, further studies with more participants and a longer follow-up are needed to validate these data.

Rates of Subjective Failure After Both Isolated and Combined Posterior Cruciate Ligament Reconstruction: A Study From the Norwegian Knee Ligament Registry 2004-2021.

BACKGROUND: Outcomes after posterior cruciate ligament (PCL) reconstruction (PCLR) have been reported to be inferior to those of anterior cruciate ligament reconstruction. Furthermore, combined ligament injuries have been reported to have inferior outcomes compared with isolated PCLR. PURPOSE/HYPOTHESIS: The purpose of this study was to report on PCLR outcomes and failure rates and compare these outcomes between isolated PCLR and multiligament knee surgery involving the PCL. The hypothesis was that combined PCL injury reconstruction would have higher rates of subjective failure and revision relative to isolated PCLR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients with primary PCLR with or without concomitant ligament injuries registered in the Norwegian Knee Ligament Registry between 2004 and 2021 were included. Knee injury and Osteoarthritis Outcome Score (KOOS) totals were collected preoperatively and at 2 years and 5 years postoperatively. The primary outcome measure was failure, defined as either a revision surgery or a KOOS Quality of Life (QoL) subscale score <44. RESULTS: The sample included 631 primary PCLR procedures, with 185 (29%) isolated PCLR procedures and 446 (71%) combined reconstructions, with a median follow-up time of 7.3 and 7.9 years, respectively. The majority of patients had poor preoperative knee function as defined by a KOOS QoL score <44 (90.1% isolated PCLR, 85.7% combined PCL injuries; P = .24). Subjective outcomes improved significantly at 2- and 5-year follow-up compared with preoperative assessments in both groups (P < .001); however, at 2 years, 49.5% and 46.5% had subjective failure (KOOS QoL <44) for isolated PCLR and combined PCLR, respectively (P = .61). At 5 years, the subjective failure rates of isolated and combined PCLR were 46.7% and 34.2%, respectively (P = .04). No significant difference was found in revision rates between the groups at 5 years (1.9% and 4.6%, respectively; P = .07). CONCLUSION: Patients who underwent PCLR had improved KOOS QoL scores relative to their preoperative state. However, the subjective failure rate was high for both isolated and multiligament PCLR. Within the first 2 years after surgery, patients who undergo isolated PCLR can be expected to have similar failure rates to patients who undergo combined ligament reconstructions.

Altered knee kinematics after posterior cruciate ligament single-bundle reconstruction-a comprehensive prospective biomechanical in vivo analysis.

Purpose: Passive tibiofemoral anterior-posterior (AP) laxity has been extensively investigated after posterior cruciate ligament (PCL) single-bundle reconstruction. However, the PCL also plays an important role in providing rotational stability in the knee. Little is known in relation to the effects of PCL single-bundle reconstruction on passive tibiofemoral rotational laxity. Gait biomechanics after PCL reconstruction are even less understood. The aim of this study was a comprehensive prospective biomechanical in vivo analysis of the effect of PCL single-bundle reconstruction on passive tibiofemoral rotational laxity, passive anterior-posterior laxity, and gait pattern. Methods: Eight patients undergoing PCL single-bundle reconstruction (seven male, one female, mean age 35.6 ± 6.6 years, BMI 28.0 ± 3.6 kg/m2) were analyzed preoperatively and 6 months postoperatively. Three of the eight patients received additional posterolateral corner (PLC) reconstruction. Conventional stress radiography was used to evaluate passive translational tibiofemoral laxity. A previously established rotometer device with a C-arm fluoroscope was used to assess passive tibiofemoral rotational laxity. Functional gait analysis was used to examine knee kinematics during level walking. Results: The mean side-to-side difference (SSD) in passive posterior translation was significantly reduced postoperatively (12.1 ± 4.4 mm vs. 4.3 ± 1.8 mm; p < 0.01). A significant reduction in passive tibiofemoral rotational laxity at 90° knee flexion was observed postoperatively (27.8° ± 7.0° vs. 19.9° ± 7.5°; p = 0.02). The range of AP tibiofemoral motion during level walking was significantly reduced in the reconstructed knees when compared to the contralateral knees at 6-month follow-up (16.6 ± 2.4 mm vs. 13.5 ± 1.6 mm; p < 0.01). Conclusion: PCL single-bundle reconstruction with optional PLC reconstruction reduces increased passive tibiofemoral translational and rotational laxity in PCL insufficient knees. However, increased passive tibiofemoral translational laxity could not be fully restored and patients showed altered knee kinematics with a significantly reduced range of tibiofemoral AP translation during level walking at 6-month follow-up. The findings of this study indicate a remaining lack of restoration of biomechanics after PCL single-bundle reconstruction in the active and passive state, which could be a possible cause for joint degeneration after PCL single-bundle reconstruction.

[Comparison of intraoperative effects of computer navigation-assisted and simple arthroscopic reconstruction of posterior cruciate ligament tibial tunnel].

Objective: To compare the intraoperative effects of computer navigation-assisted versus simple arthroscopic reconstruction of posterior cruciate ligament (PCL) tibial tunnel. Methods: The clinical data of 73 patients with PCL tears who were admitted between June 2021 and June 2022 and met the selection criteria were retrospectively analysed, of whom 34 cases underwent PCL tibial tunnel reconstruction with navigation-assisted arthroscopy (navigation group) and 39 cases underwent PCL tibial tunnel reconstruction with arthroscopy alone (control group). There was no significant difference in baseline data between the two groups, including gender, age, body mass index, side of injury, time from injury to surgery, preoperative posterior drawer test, knee range of motion (ROM), Tegner score, Lysholm score, and International Knee Documentation Committee (IKDC) score between the two groups ( P>0.05). The perioperative indicators (operation time and number of guide wire drillings) were recorded and compared between the two groups. The angle between the graft and the tibial tunnel and the exit positions of the tibial tunnel in the coronal, sagittal, and transverse planes respectively were measured on MRI at 1 day after operation. The knee ROM, Tegner score, Lysholm score, and IKDC score were evaluated before operation and at last follow-up. Results: The operation time in the navigation group was shorter than that in the control group, and the number of intraoperative guide wire drillings was less than that in the control group, the differences were significant ( P<0.05). Patients in both groups were followed up 12-17 months, with an average of 12.8 months. There was no perioperative complications such as vascular and nerve damage, deep venous thrombosis and infection of lower extremity. During the follow-up, there was no re-injuries in either group and no revision was required. The results showed that there was no significant difference in the exit positions of the tibial tunnel in the coronal, sagittal, and transverse planes between the two groups ( P>0.05), but the angle between the graft and the tibial tunnel was significantly greater in the navigation group than in the control group ( P<0.05). At last follow-up, 30, 3, 1 and 0 cases were rated as negative, 1+, 2+, and 3+ of posterior drawer test in the navigation group and 33, 5, 1, and 0 cases in the control group, respectively, which significantly improved when compared with the preoperative values ( P<0.05), but there was no significant difference between the two groups ( P>0.05). At last follow-up, ROM, Tegner score, Lysholm score, and IKDC score of the knee joint significantly improved in both groups when compared with preoperative values ( P<0.05), but there was no significant difference in the difference in preoperative and postoperative indicators between the two groups ( P>0.05). Conclusion: Computer-navigated arthroscopic PCL tibial tunnel reconstruction can quickly and accurately prepare tunnels with good location and orientation, with postoperative functional scores comparable to arthroscopic PCL tibial tunnel reconstruction alone.

Technique and Outcomes of Posterior Cruciate Ligament Repair With Augmentation.

Background: Posterior cruciate ligament (PCL) injuries to the knee are uncommon, and ideal surgical management of these injuries is unclear. Current surgical techniques include PCL reconstruction with remnant debridement, remnant-preserving techniques, and primary PCL repair. Augmentation of PCL repairs and reconstructions has been proposed to protect repairs or grafts in the postoperative period. Purpose: To describe PCL repair with the hamstring autograft augmentation technique and examine our preliminary midterm outcomes from a sequential cohort of patients. Study Design: Case series; Level of evidence, 4. Methods: The authors identified patients at their institution who underwent remnant-preserving primary PCL repair with hamstring autograft augmentation for both isolated tears and tears associated with multiligament knee injury (MLKI). Patient-reported outcomes were evaluated at a minimum 2-year follow-up using the International Knee Documentation Committee (IKDC) subjective knee form, the 12-item Short Form Survey, and a custom return-to-play questionnaire. Patient-reported outcomes data were summarized, and the predictors of outcomes from the descriptive data and clinical measures were further examined. Results: A total of 23 patients with a mean follow-up of 5.3 years met the inclusion criteria. Of these patients, 87% were associated with MLKI. The mean IKDC score was 87.7. Approximately 83% of patients were able to successfully return to their sport or occupation. Among 19 athletes, only 2 reported being unable to return to their preinjury level of sport because of limitations from their PCL surgery. Patient-reported outcome scores and return to sport or occupation did not have a statistically significant association with age, sex, body mass index, time from injury to surgery, or follow-up time. Conclusion: Outcomes of our cohort with remnant-preserving primary PCL repairs with hamstring autograft augmentation demonstrated comparable clinical outcomes to previously published PCL data. The advantages of remnant preservation, primary repair, and augmentation with an independent hamstring autograft reconstruction are combined within this technique.

Adverse Events After Isolated Posterior Cruciate Ligament Reconstruction: A National Database Study.

Background: Optimal management after posterior cruciate ligament (PCL) injury remains an active area of research, as reconstruction is technically challenging and poses unique risks in the posterior knee. Studies have reported variable rates of complications. Purpose: To describe the rates of readmission, emergency department (ED) visits, and postoperative complications within 90 days of isolated PCL reconstruction (PCLR) in a large, national cohort to better understand the perioperative variables that influence a practitioner's decision of whether to pursue operative versus nonoperative management. Study Design: Descriptive epidemiology study. Methods: PCLRs from January 1, 2010, through August 31, 2020, were identified in PearlDiver, a national administrative database. Patients with concomitant ligament surgery and those with fewer than 90 days of postoperative database activity were excluded. Deep vein thromboses, pulmonary embolisms, surgical site infections, compartment syndrome, and vascular events within 90 days of surgery were identified, as were 90-day readmissions and ED visits. Logistic regression models were built in PearlDiver to calculate odds ratios (ORs) for ED utilization. Results: The final cohort consisted of 1154 patients with isolated PCLR (mean age, 34 ± 16 years; 62% male). Most patients were located in the Southern United States (n = 417; 36.1%), and most had commercial insurance (n = 992; 86%). The 90-day rates of adverse events were as follows: deep vein thrombosis (13; 1.1%), pulmonary embolism (19; 1.6%), surgical site infection (<11; <1%), compartment syndrome (<11; <1%), vascular event (<11; <1%), readmission (13, 1.1%), and ED utilization (99; 8.6%). The majority of emergency department visits (52%) occurred in the first 2 weeks postoperatively. Predictive factors for ED utilization included Elixhauser Comorbidity Index score (OR = 1.31 per 2-point increase) and Medicaid insurance (OR = 2.03 relative to commercial insurance). Conclusion: The current study reported rates of adverse events after isolated PCLR in a large, national cohort. The results provide important context for decisions about optimal management of PCL injury.

Decreased posterior tibial slope is a risk factor for primary posterior cruciate ligament rupture and posterior cruciate ligament reconstruction failure: A systematic review.

PURPOSE: To determine bony knee morphological factors associated with primary posterior cruciate ligament (PCL) rupture or PCL graft failure after PCL reconstruction. METHODS: Three databases, namely MEDLINE, PubMed and EMBASE, were searched on 30th May 2023. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data such as receiver operating characteristic curve parameters, as well as p-values for comparisons of values between patients with PCL pathology and control patients, were recorded. RESULTS: Nine studies comprising 1054 patients were included. Four studies reported that patients with PCL injury had flatter medial posterior tibial slopes (MTS) than controls, with mean values of 4.3 (range: 3.0-7.0) and 6.5 (range: 5.0-9.2) degrees, respectively. Two studies reported an MTS cutoff value ranging below 3.90-3.93° being a significant risk factor for primary PCL rupture or PCL graft failure. Two studies reported that shallow medial tibial depths were associated with primary PCL rupture, with mean values of 2.1 (range: 2.0-2.2) and 2.6 (range: 2.4-2.7) mm in PCL injury and control groups, respectively. Stenotic intercondylar notches and femoral condylar width were not consistently associated with PCL injuries. CONCLUSION: Decreased MTS is associated with primary PCL rupture and graft failure after PCL reconstruction with values below 3.93° being considered as a significant risk factor. Less common risk factors include shallow medial tibial depth, while femoral condylar width and parameters with regards to the intercondylar notch, such as notch width, notch width index and intercondylar notch volume, demonstrated conflicting associations with primary or secondary PCL injuries. LEVEL OF EVIDENCE: Level III.

The Effect of Aging on Outcomes after Posterior Cruciate Ligament Reconstruction: Older (≥ 50 Years) Versus Younger (< 50 Years) Patients.

Background: This study aimed to evaluate the clinical and radiological outcomes after posterior cruciate ligament (PCL) reconstruction in ≥ 50-year-old patients. Methods: This retrospective case-control study reviewed 28 patients (age, ≥ 50 years) who underwent PCL reconstruction from 2004 to 2018. These patients were 1 : 1 matched to < 50-year-old patients by sex. Clinical, radiological, and survivorship outcomes of the patients were assessed at the final follow-up. Failure of PCL reconstruction was defined as the requirement for additional surgery (revision PCL reconstruction, high tibial osteotomy, or arthroplasty) due to unrelieved symptoms or grade III instability on stress radiographs. Results: The mean follow-up periods (± standard deviation) in < 50- and ≥ 50-year-old patients were 3.9 ± 1.0 years and 3.6 ± 1.9 years, respectively (p = 0.583). In < 50- and ≥ 50-year-old patients, the mean International Knee Documentation Committee scores were 64.1 ± 10.3 and 53.5 ± 17.3; mean Lysholm scores were 81.4 ± 13.0 and 66.3 ± 21.5; and mean Tegner activity scores were 6.1 ± 1.4 and 4.8 ± 1.7, respectively (p = 0.032, p = 0.018, and p = 0.016, respectively). Side-to-side differences in posterior translation on Telos stress radiographs at the final follow-up were 4.4 ± 1.4 mm and 6.9 ± 3.0 mm in < 50- and ≥ 50-year-old patients, respectively (p < 0.001). According to Kaplan-Meier analysis, the failure-free survival rates of both groups were significantly different in the follow-up period (p = 0.014). The failure-free survival rates for < 50- and ≥ 50-year-old patients were 100% and 78.6%, respectively. Conclusions: Clinical, radiological, and survivorship outcomes were inferior among ≥ 50-year-old patients after PCL reconstruction. Thus, surgeons should be careful when deciding and performing PCL reconstruction in patients 50 years old or over.

The optimal tibial tunnel placement to maximize the graft bending angle in the transtibial posterior cruciate ligament reconstruction: a quantitative assessment in three-dimensional computed tomography model.

Background: The graft bending angle created by the graft and the tibial tunnel has inevitably occurred during the transtibial posterior cruciate ligament (PCL) reconstruction. However, few studies quantitively analyzed this angle. This study aimed to (I) explore the optimal tibial tunnel placement to maximize the graft bending angle in the PCL reconstruction; (II) reveal the effect of the tibial tunnel placement on the graft bending angle. Methods: This was an in-vitro surgical simulation study based on the three-dimensional (3D) computed tomography (CT). A total of 55 patients who took CT scanning for knee injuries were selected (April 2020 to January 2022) from the local hospital database for review. The 3D knee models were established on the Mimics software based on the knees' CT data. Using the Rhinoceros software to simulate the transtibial PCL reconstruction on the 3D CT knee model. The anteromedial and anterolateral tibial tunnel approaches were simulated with different tibial tunnel angle. The graft bending angle and tibial tunnel length (TTL) with different tibial tunnel angles were quantitively analyzed. Results: The graft bending angle in anterolateral approach with a 50° tibial tunnel angle was significantly greater than it in anteromedial approach with a 60° tibial tunnel angle (P<0.001). There was no difference of the graft bending angle between the anterolateral approach with a 40° tibial tunnel angle and the anteromedial approach with a 60° tibial tunnel angle (P>0.05). The graft bending angle showed a strong correlation with the tibial tunnel angle (for anteromedial approach: r=0.759, P<0.001; for anterolateral approach: r=0.702, P<0.001). The best-fit equation to calculate the graft bending angle based on the tibial tunnel angle was Y = 0.89*X + 59.05 in anteromedial tibial tunnel approach (r2=0.576), and was Y = 0.78*X + 80.21 anterolateral tibial tunnel approach (r2=0.493). Conclusions: The graft bending angle and TTL will significantly increase as the tibial tunnel angle becomes greater. Maximizing the tibial tunnel angle (50° tibial tunnel angle) in the anterolateral approach could provide the greatest graft bending angle in the PCL reconstruction. No matter how the tibial tunnel angle is changed in the anteromedial approach, using anterolateral approach might reduce the killer turn effect more effectively than using anteromedial approach.

Well-Leg Compartment Syndrome Due to Hemilithotomy Positioning after Arthroscopic Reconstruction of the PCL.

Introduction: Acute compartment syndrome (ACS) occurs due to decreased perfusion of an osseofascial space due to increased compartmental pressure. Due to its potentially devastating sequelae, emphasis is placed on its prompt diagnosis. While fractures continue to be the most common cause of ACS, mechanisms such as crush injuries and even surgical positioning are described etiologies of compartment syndrome. ACS of the well-leg from hemilithotomy positioning has been previously depicted in medical literature; however, there have been no illustrations of this complication after elective arthroscopic-assisted posterior cruciate ligament (PCL) reconstruction. Case Report: This report discusses a patient undergoing PCL reconstruction who developed an ACS in the non-operative extremity that was positioned in hemilithotomy in a leg positioner. Conclusion: ACS is an uncommon but serious complication that can occur from hemilithotomy positioning. Surgeons should be mindful of risk factors that can place a patient at higher risk, including length of the case, body habitus, height of elevation of the leg, and method of leg support. The prompt recognition and surgical management of ACS can prevent the devastating long-term complications.

POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: ARE THE RESULTS SIMILAR TO ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION?

Objective: To report and compare the results of posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL) reconstructions. Methods: In total, 42 patients were retrospectively evaluated, 20 with isolated PCL injuries (group 1) and 22 with isolated ACL ones (group 2) who were subjected to arthroscopic ligament reconstruction with autologous grafts and followed up for at least two years. To evaluate the results in group 1, objective IKDC and Lysholm scores, posterior drawer tests, and evaluations by a KT-1000 arthrometer were used, whereas for group 2, subjective IKDC and Lysholm score and the Lachman test were employed. To compare groups, objective IKDC and Lysholm scores and assessment via a KT-1000 arthrometer were considered. Results: Intragroup analysis showed improved results for all variables (p < 0.001) in both groups. Comparisons between groups showed a significant difference in objective IKDC scores (p < 0.001), but no such disparities for Lysholm ones (p = 0.052), clinical tests (p = 0.058) or evaluation by KT-1000 (p = 0.129). Conclusion: Treatment restored knee stability and function in both groups. Comparisons between groups showed that PCL reconstructions had inferior results than ACL ones according to patients' objective IKDC scores. Level of Evidence II, Retrospective Study.

Objetivo: Reportar e comparar os resultados da reconstrução do ligamento cruzado posterior (LCP) e do ligamento cruzado anterior (LCA). Métodos: Foram avaliados retrospectivamente 42 pacientes: 20 com lesão isolada do LCP (grupo 1) e 22 com lesão isolada do LCA (grupo 2), submetidos à reconstrução ligamentar artroscópica com enxertos autólogos e acompanhados por pelo menos dois anos. Para avaliação dos resultados no grupo 1, foram utilizados o escore do International Knee Documentation Committee (IKDC) objetivo, escore de Lysholm, teste da gaveta posterior e avaliação pelo artrômetro KT-1000; e, para o grupo 2, foram utilizados o IKDC subjetivo, escore Lysholm e teste de Lachman. Para comparação entre os grupos, foram considerados o IKDC objetivo, escore Lysholm e avaliação pelo artrômetro KT-1000. Resultados: Ambos os grupos demonstraram melhora dos resultados na análise intragrupo em todas as variáveis (p < 0,001). Na comparação intergrupos, observou-se diferença significativa no IKDC objetivo (p < 0,001), não sendo observada diferença no escore Lysholm (p = 0,052), nos testes clínicos (p = 0,058) ou na avaliação pelo KT-1000 (p = 0,129). Conclusão: A estabilidade e função do joelho foram restauradas em ambos os grupos. Na comparação intergrupos, a reconstrução do LCP apresentou resultados inferiores à reconstrução do LCA no critério IKDC objetivo. Nível de Evidência II, Estudo Retrospectivo.

Effect of Posterior Tibial Slopes on Graft Survival Rates at 10 Years After Primary Single-Bundle Posterior Cruciate Ligament Reconstruction.

BACKGROUND: Recent biomechanical studies have reported that stress on the posterior cruciate ligament (PCL) graft increases as the posterior tibial slope (PTS) decreases (flattened) in knees with single-bundle (SB) and double-bundle PCL reconstruction. Clinical studies of SB PCL reconstruction have shown that a flattened PTS is associated with a lesser reduction in posterior tibial translation. There is no long-term study on the clinical outcomes and graft survival rates of SB PCL reconstruction based on the medial and lateral PTSs measured on magnetic resonance imaging. HYPOTHESIS: Flattened medial and lateral PTSs are associated with poor clinical outcomes and graft survival rates at a minimum 10-year follow-up after SB PCL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In this cohort study, we retrospectively reviewed 46 patients (mean age, 28.8 ± 9.9 years) who underwent primary SB PCL reconstruction between 2000 and 2009. They were followed up for a minimum of 10 years. The medial and lateral PTSs were measured on preoperative magnetic resonance imaging. As a previous study reported that a steeper medial or lateral PTS showed a higher risk of anterior tibial translation at thresholds of 5.6° and 3.8°, respectively, the patients were divided into 2 groups based on the cutoff values of both the medial (≤5.6° vs >5.6°) and lateral (≤3.8° vs >3.8°) PTSs. Clinical scores (International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity score), radiological outcomes (side-to-side difference [SSD] on stress radiography and osteoarthritis progression), and graft survival rates were compared between the groups at the last follow-up. RESULTS: All clinical scores and the progression of osteoarthritis demonstrated no significant difference between the 2 subgroups of both the medial and lateral PTS groups. The mean SSD on stress radiography after SB PCL reconstruction was significantly greater in patients with a medial PTS ≤5.6° than in patients with a medial PTS >5.6° (8.4 ± 3.9 vs 5.1 ± 2.9 mm, respectively; P = .030), while the lateral PTS subgroups after SB PCL reconstruction demonstrated no significant difference. The minimum 10-year graft survival rate was significantly lower in patients with a medial PTS ≤5.6° (68.4% vs 92.6%, respectively; P = .029) and a lateral PTS ≤3.8° (50.0% vs 91.7%, respectively; P = .001). CONCLUSION: A flattened medial PTS (≤5.6°) was associated with an increased SSD on stress radiography, and both flattened medial (≤5.6°) and lateral (≤3.8°) PTSs resulted in lower graft survival rates at a minimum 10-year follow-up after primary SB PCL reconstruction.

Influence of the Tibial Tunnel Angle and Posterior Tibial Slope on "Killer Turn" during Posterior Cruciate Ligament Reconstruction: A Three-Dimensional Finite Element Analysis.

This study aimed to evaluate the influence of various posterior tibial slopes (PTSs) and tibial tunnel angles (TTAs) on "killer turn" in posterior cruciate ligament (PCL) reconstruction by using three-dimensional finite element analysis (FEA). The study models were created using computed tomography images of a healthy young Asian male. Using SolidWorks, PCL grafts and tibial bone tunnels at different tibial drilling angles (30°, 45°, 60°) were developed. Anterior opening wedge high tibial osteotomy (aOW-HTO) was performed to evaluate the influence of the PTS (+8°, +4°, native, -4°, -8°). An FEA was performed utilizing the ANSYS software program. In the same PTS model, the peak of the equivalent Von Mises stress in PCL grafts decreased as the angle of the TTA increased. In the same TTA model, the peak of the Von Mises in PCL grafts decreased as the PTS angle increased. The "high-contact stress area" (contact stress greater than 10 MPa) was diminished when the TTA and PTS were increased. aOW-HTO was used to steepen the PTS, and a larger TTA may reduce the stress at the "killer turn" during PCL reconstruction. In conclusion, the study findings suggest that using aOW-HTO to steepen the PTS and a larger TTA may reduce the stress at the "killer turn" during PCL reconstruction. The usefulness and safety of this surgical procedure need to be evaluated in future clinical studies.

Posterior cruciate ligament reconstruction using PCL inlay technique with the patient supine in bicruciate ligament injury reconstruction.

BACKGROUND: Surgical reconstruction of the posterior cruciate ligament (PCL) can be technically challenging given the proximity of the popliteal artery to the PCL tibial insertion. This "no-safe zone" makes some knee surgeons less confident and willing to perform this surgical procedure. SURGICAL TECHNIQUE: We present a PCL tibial inlay reconstruction technique using a set of instruments involving three tools (a slot cut, a bone plug positioner, and an impactor). CONCLUSION: This set of instruments allows a more reproducible posteromedial approach and to produce a PCL tibial slot in a posterior cruciate ligament inlay reconstruction with the patient supine in bicruciate ligament injury reconstruction.

Allografts as alternative to autografts in primary posterior cruciate ligament reconstruction: a systematic review and meta-analysis.

PURPOSE: Following posterior cruciate ligament (PCL) rupture, autografts and allografts are routinely used for its reconstruction. This study investigated the efficacy and safety of allografts for primary PCL reconstruction, comparing them to autografts in terms of patient-reported outcome measures (PROMs), functional tests, and complications. METHODS: This study followed the PRISMA guidelines. PubMed, Web of Science, Google Scholar, Embase, and Scopus were accessed in October 2022. All the clinical studies investigating the outcomes of primary PCL reconstruction using allografts, or comparing the outcomes of allografts versus autografts, were accessed. The outcomes of interests were: instrumental laxity, range of motion (ROM), Telos stress radiography, drawer test, International Knee Documentation Committee (IKDC), Tegner Activity Scale, and the Lysholm Knee Scoring Scale. Data on complications were also recorded. RESULTS: A total of 445 patients were included. The mean follow-up was 45.2 ± 23.8 months. The mean age of the patients was 30.6 ± 2.2 years. The time span between the injury and surgical intervention was 12.9 ± 10 months. Overall, 28% (125 of 445 patients) were women. Good baseline comparability was found between the two cohorts. No difference was found in terms of Lysholm Score, ROM, Tegner Scale, IKDC, arthrometer laxity, drawer test, and Telos stress radiography. No difference was found in the rates of anterior knee pain and revision. CONCLUSION: Allografts can be considered a suitable alternative to autografts for PCL reconstruction. LEVEL OF EVIDENCE: III.