ABSTRACT
Purpose
Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries are common and present challenges in management. While ACL reconstruction has been established, the optimal approach for combined ACL and MCL injuries remains debatable owing to the varying severity and chronicity of MCL injuries. This study aimed to describe a novel surgical technique for chronic ACL and grade III MCL injuries and assess whether simultaneous ACL and MCL reconstruction improves chronic MCL instability.
Methods
A total of 41 patients diagnosed with combined ACL and MCL injuries were included in the study. Twenty‐five patients were allocated into the simple ACL reconstruction (SAR) group while 16 patients were allocated into the simultaneous ACL and MCL reconstruction (SAMR) group according to MCL injury severity. The surgical technique utilized a single ipsilateral hamstring autograft for both ACL and MCL reconstruction. Clinical assessments, including range of motion (ROM), functional score, Lachman test, and valgus instability, were conducted before and after surgery. Postoperative magnetic resonance imaging (MRI) was used to evaluate graft quality.
Results
Postoperative outcomes revealed significant improvements in ROM, functional scores, Lachman test, and valgus instability in both groups. There were no significant differences between the SAR and SAMR groups, suggesting that patients with combined ACL rupture and severe MCL injuries can achieve similar stability outcomes as those with ACL rupture and mild MCL injuries. The MRI results revealed high‐quality grafts in both groups.
Conclusion
This study introduces a novel technique using simple hamstring autografts for simultaneous ACL and MCL reconstruction, and this surgical technique can achieve knee stability comparable to that of low‐grade MCL injuries and can be used for single ACL reconstruction. Further research with larger sample sizes and long‐term follow‐up is needed to confirm these findings.
Keywords: anterior cruciate ligament, hamstring autograft, medial collateral ligament, reconstruction, valgus instability
In the present study, we outlined a novel method involving the use of a single hamstring autograft for simultaneous reconstruction of the ACL and MCL. This approach can result in comparable stability, MRI findings, and functional outcomes as those who have low‐grade MCL injuries and undergo a single ACL reconstruction.
Abbreviations
- ACL
anterior cruciate ligament
- ACLR
anterior cruciate ligament reconstruction
- IKDC
International Knee Documentation Committee score
- MCL
medial collateral ligament
- MRI
magnetic resonance imaging
- PCL
posterior cruciate ligament
- POL
posterior oblique ligament
- ROM
range of motion
- SAMR
simultaneous anterior cruciate ligament and magnetic resonance imaging reconstruction
- SANE
single assessment numeric evaluation
- SAR
simple anterior cruciate ligament reconstruction
- SI
signal intensity
- sMCL
superficial medial collateral ligament
1. Introduction
Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries represent the most common two‐ligament injury of the knee, with MCL injuries occurring concomitantly in 20%–38% of ACL injuries [1, 2]. Sports involving flexion and external rotation motions with valgus stress at the knee joint is a common injury mechanism [3, 4]. While anterior cruciate ligament reconstruction (ACLR) has become the standard of care for severe ACL injuries, the optimal management strategy for combined ACL and MCL injuries remains a topic of debate [5, 6, 7].
MCL injuries can result in chronic medial knee instability, potentially leading to a poor prognosis if not appropriately managed [8, 9]. Medial instability is graded from Grade I to III: Grade I injuries involve microscopic tearing with no instability or joint widening, Grade II injuries are partial tears with minor joint widening and no instability, and Grade III lesions demonstrate a total loss of integrity with instability [10]. Generally, nonsurgical management is effective for treating acute MCL grade I–II injuries, whereas surgical intervention is effective for patients with acute grade III MCL injuries or chronic MCL insufficiency after failure of conservative treatments [11, 12, 13]. Clinically, in isolated ACL rupture cases, there is a high incidence of combined ACL and MCL injuries [14]. Furthermore, studies have indicated that a concomitant lesion of the MCL complex with an ACL injury is associated with a higher failure rate of revision ACLR [15, 16]. This concomitance can lead to a 13.6–16.8‐fold greater risk of failure [15, 16]. Hence, a comprehensive evaluation involving imaging examinations and physical assessments is crucial.
Reconstruction can be broadly categorized on the basis of the source of the tendon graft as allograft or autograft. Autografts can be further divided into collateral or ipsilateral to the injury site. Gallo et al. reported a technique utilizing a single Achilles tendon allograft for combined ACL and MCL reconstruction [17]. The use of a single graft reduces the cost and preparation time associated with using two grafts. Nevertheless, allografts have shortcomings, including issues related to biological incorporation [18], disease transmission [19], and a relatively high failure rate, especially in the young population [20]. Hetsroni and Mann presented an alternative approach for simultaneous reconstruction of the MCL and ACL using the ipsilateral quadriceps tendon‐bone and bone‐patellar tendon‐bone [21]. Nevertheless, this method has drawbacks, including an extended rehabilitation period needed for the complete restoration of the extensor mechanism and an increased likelihood of patellar fracture. Selim described a technique that employs hamstring tendons from the contralateral limb as the ACL graft and the gracilis tendon from the ipsilateral limb as the MCL graft. However, the use of two autografts from different limbs might prolong the rehabilitation period and increase the potential risk of infection and instability in the contralateral knee [22].
The present study was therefore undertaken with two primary objectives: (1) to describe a modified reconstruction technique for combined chronic ACL and grade III MCL injuries, and (2) to determine whether simultaneous ACL and MCL reconstruction can improve chronic MCL instability. We hypothesized that graft reconstructions for chronic MCL injuries may be advisable to prevent progressive valgus instability and enable early rehabilitation in patients with combined ACL and grade III MCL injuries.
2. Method
2.1. Patients
This study received approval from the associated Joint Institutional Review Board (TMU‐JIRB No. N202312103). Consecutive patients diagnosed with ACL injury through magnetic resonance imaging (MRI) from July 2015 to March 2021 were enrolled. An initial cohort of 178 patients was initiated. The inclusion criteria are: (1) all of whom underwent comprehensive MRI evaluation and physical examination conducted by a single surgeon at a single medical center with diagnosis of ACL injury; (2) combined chronic ACL and MCL injuries; (3) at least 2 years of follow‐up. The exclusion criteria are: (1) patients with concomitant posterior cruciate ligament (PCL) or lateral collateral ligament injuries; (2) individuals under the age of 18 years; (3) patients who required meniscus repair.
Patients with combined ACL and MCL injuries without a medial meniscus root tear or posterior oblique ligament (POL) were included in the study. In cases of acute injury, conservative treatment involving a knee brace was initiated. We requested patients to have active range of motion (ROM) under non‐weight‐bearing to prevent arthrofibrosis. When patients were shifted to weight‐bearing status, a hinged knee brace with a 0°–30° ROM should be worn, and additional ROM modifications of up to 120° should be made in a 3‐month clinic follow‐up series. The assessment via MRI (SignaHDxt 1.5T system, GE Medical Systems, Milwaukee, WI, USA) was conducted after a minimum follow‐up period of 3 months, during which the MCL and ACL status were re‐evaluated (Figure 1). Cases with an injury period longer than 3 months at the initial visit did not require conservative treatment or a three‐month follow‐up. As a result, all the cases were categorized as chronic. The primary diagnosis of Grade III MCL injury without a medial meniscus root tear or POL injury was established through preoperative MRI and confirmed intraoperatively via clinical examination under anesthesia. The presence of medial joint space opening during valgus stress testing at 30° of knee flexion indicated MCL injury. If the medial joint line exhibited laxity in full extension with valgus stress, the injury was defined as Grade III [23]. We classified MCL injuries according to the location of the injury in the superficial layer. Type I injuries are referred to as lesions located at the femoral attachment site; type II injuries are referred to as disruptions localized at the tibial insertion site; and type III injuries are evident over the entire length of the superficial layer [24].
FIGURE 1.
Knee MRI of “patient A” in the SAMR group. (A, B) First MRI after injury; (C, D) MRI after 3 months of follow‐up. (A) Sagittal fat‐suppressed proton density‐weighted MRI showing ACL rupture, and (B) coronal T2 MRI revealing MCL (white arrows) injury with femoral condyle and proximal tibia bone edema. Three months later, (C) sagittal fat‐suppressed proton density‐weighted MRI revealed increased intensity and fiber discontinuity in the ACL. (D) Coronal T1‐wighted MRI revealed MCL (white arrows) was detached from the femoral site and still mildly swollen.
We categorized patients into two groups on the basis of the severity of chronic MCL injury. Group simple ACL reconstruction (SAR) comprised patients with ACL ruptures and grade I–II MCL injuries. Patients with combined chronic ACL and grade III MCL injuries were assigned to Group simultaneous ACL and MCL reconstruction (SAMR). In Group SAR, patients were managed with SAR after wearing a knee brace for at least 2 months as part of conservative treatment. In contrast, all patients in Group SAMR underwent simultaneous ACL and MCL reconstruction via an ipsilateral single hamstring tendon autograft after wearing a knee brace for 3 months. All surgical procedures were performed by an experienced surgeon at a single institution.
2.2. Operation Technique
Surgery for all cases was performed by a single surgeon. Prior to reconstruction, exploratory arthroscopy was conducted to assess the presence of additional lesions, such as meniscus tears, cartilage damage, or loose bodies.
The procedure for ACL reconstruction was detailed in a previous study. It begins with a longitudinal incision on the anteromedial tibial surface at the level of the pes anserinus. The semitendinosus and gracilis tendons were harvested from their distal insertions via a closed tendon stripper. In the SAR group, semitendinosus and gracilis were folded and fashioned into equal length and tension and were sutured together with nonabsorbable sutures (No. 5 Ethibond) to create a four‐stranded hamstrings graft of appropriate length (65–75 mm). In the SAMR group, the semitendinosus graft was then folded twice to create a four‐stranded graft of appropriate length (65–75 mm), with a 1‐min pretension applied for tension. The diameter of the semitendinosus graft or hamstrings graft ranged from 8 to 10 mm. TightRope RT implants (Arthrex Inc., Naples, Florida, USA) were attached to the femoral side, and whipstitches were placed at the tibial ends of the tendon via nonabsorbable sutures (No. 5 Ethibond) for later fixation with the cortical screw post on the proximal tibia.
Once graft preparation was completed, the femoral socket and tibial tunnel were established. Under maximal knee flexion (≥ 130°), the femoral socket was drilled through the anteromedial portal via an inside‐out approach to reach the anatomical anteromedial bundle insertion site on the lateral femoral condyle. The femoral socket was positioned at 10 o'clock for the right knees and 2 o'clock for left knees. Initially, a 4.5 mm drill was used to create a path for the TightRope RT implants, followed by a reamer suitable for the graft diameter to achieve a femoral socket depth of approximately 20–25 mm. The transtibial technique was used for the tibial tunnel, with a drill pin passing through the center of the ACL footprint and aligned at an angle of 47.5°–52.5°. Reamers compatible with the graft size were then used to adjust the tibial tunnel diameter.
Subsequently, the graft was introduced into the joint, with the passing suture guiding the TightRope sutures and button through. Following 10 cycles of flexion and extension, the tibial end of the graft was secured via a bioabsorbable interference screw within the tibial tunnel. Finally, a cortical screw post was placed on the proximal tibia.
For the SAMR group, simultaneous MCL reconstruction was performed. In contrast to the SAR group, a longer longitudinal incision (approximately 6 cm) was made on the medial parapatellar region from the superior pole of the patella to the level of the pes anserinus. The semitendinosus and gracilis tendons were harvested from their distal insertions via a closed tendon stripper. For MCL reconstruction, the gracilis graft was folded to create a double‐stranded graft of suitable length. TightRope RT implants were subsequently utilized to secure the gracilis tendons on the femoral side; whipstitches were subsequently placed at the tibial ends of the graft with nonabsorbable sutures (No. 5 Ethibond) for later fixation with the cortical screw post onto the proximal tibia in cases of tibial‐sided MCL rupture.
On the femoral side, the graft was positioned and secured via TightRope RT implants and an interference screw technique at the superior and posterior to the medial epicondyle. Owing to the longer fixation distance of the transfemoral tunnel for the MCL graft, we used double femoral fixation to prevent the windshield wiper effect [25, 26]. A transfemoral path was drilled for the TightRope RT implant to pass through. The diameter of the gracilis graft was measured, and a transfemoral tunnel of appropriate size was reamed to a depth of 25–30 mm. The graft sutures from the looped end were placed in the eyelet of the guide pin and pulled through the lateral cortex. A properly sized interference screw, corresponding to the graft tunnel diameter, was placed within the tunnel to fix the graft. From the tibial end to the femoral side, the entire graft was secured to the remaining fibers of the ruptured MCL via advanced repair with nonabsorbable sutures. In cases of tibial‐sided MCL rupture or insufficient ligamentous integrity, adjunctive fixation with a cortical screw post on the proximal tibia was employed to reinforce stability (Figures 2 and 3).
FIGURE 2.
Postoperative anteroposterior and lateral X‐ray of “patient A” in the SAMR group.
FIGURE 3.
A left knee was drawn. A diagrammatic representation of the surgical steps of our MCL reconstruction technique is shown in the figure. The pink tendon represents a hamstring autograft secured to the remaining fibers of the ruptured MCL via advanced repair with nonabsorbable sutures. The ACL reconstruction is not presented in the figure.
2.3. Rehabilitation
All patients followed a standardized rehabilitation protocol. The knee was immobilized in full extension with a brace postoperatively. Quadriceps isometric exercises were initiated immediately. Partial weight‐bearing with the extension brace was maintained for 2 weeks, progressing to full weight‐bearing over the subsequent 4 weeks. A hinged knee brace was applied postoperatively and maintained for 3 months to enhance collateral ligament stability. Physical therapy began at 2 weeks with gentle range‐of‐motion exercises, achieving 90° of flexion by 4 weeks and full flexion by 8 weeks. Muscle strengthening was performed with closed kinetic chain exercises. Return to sports was permitted at 9–12 months.
2.4. Assessment of Clinical Outcomes
Physical examinations were conducted by an experienced orthopedic doctor both before and during the periods of 15 ± 3 months and 18 ± 3 months following the operation in the SAR group and SAMR group, respectively, at the outpatient clinic, which was deemed the 1‐year follow‐up outcome. Experienced orthopedic surgeons performed ROM measurements and administered the Lachman test. The valgus stress test was performed preoperatively in the operating room under anesthesia and postoperatively at the outpatient department. During the application of the valgus stress test, at knee flexion angles of 30° or full extension, increased gapping with a distinct endpoint indicated Grade I, whereas gapping without a definitive endpoint indicated Grade II [27]. If the medial joint line exhibited laxity in full extension with valgus stress, it was defined as Grade III [23]. Lachman test grading does not involve the use of measurement instruments such as the KT‐1000. Some results were inconclusive, resulting in their classification as “I–II” or “II–III”. Grades equal to or lower than Grade II indicated stability with a firm end‐feel, whereas grades higher than Grade II indicated instability without a firm end‐feel [28]. ROM measurements for flexion and extension of the injured knee were taken both before and after the operation. The functional assessments included recording the IKDC score and the Tegner activity level scale before the operation. Subsequently, subjective IKDC scores, SANE scores, and Tegner activity level scale records were documented during follow‐up clinic visits or through telephone inquiries conducted 2 years postoperatively.
At the minimum 1‐year follow‐up, all patients underwent postoperative MRI. An orthopedic doctor, who was unaware of the patients' clinical data, independently evaluated the MRI data (Figure 4). The MRI findings were collectively evaluated. The postoperative quality of the ACL and PCL was assessed via the T2‐weighted sagittal view, whereas the MCL was evaluated via the T2‐weighted coronal view. The signal intensity (SI) of the intra‐articular portion of the ACL and MCL grafts was analyzed and graded on a scale: Grade I represented a normal SI similar to that of the PCL; Grade II represented > 50% of the grafts with a normal SI; and Grade III represented < 50% of the grafts with a normal SI [29, 30, 31, 32].
FIGURE 4.
Postoperative 12‐month MRI and SI evaluation in the T2‐weighted coronal view in “Patient A”. The red lines represent the contour of the ACL graft, and the green lines represent the contour of the MCL graft. Compared with the PCL (not shown in this image), these grafts were both Grade I.
2.5. Statistical Analysis
The data are presented as the means and standard deviations for continuous variables. Statistical analysis was conducted via IBM SPSS Statistics for Mac OS (IBM Corporation, Armonk, NY, USA) and R 4.1.0 (R Core Team, Vienna, Austria). Normal distribution was confirmed by the Shapiro–Wilk test, except for the subgroup in MCL reconstruction, which was due to the small sample size. We then analyzed the significant differences in all continuous variables via the independent t test, and the continuous variables in MCL reconstruction were analyzed via the Mann–Whitney U test instead. The chi‐square test and Fisher's exact test were used for categorical variables. The level of significance was set at p < 0.05.
3. Results
3.1. Allocation and Demographic Data
A total of 178 patients who experienced ACL injury on MRI were included. A flowchart regarding the allocation is shown in Figure 5. A total of 122 patients who were ultimately diagnosed with isolated ACL injury and 5 patients who had multiple‐ligament injuries other than MCL injury were excluded. Fifty‐one patients who had combined ACL and MCL injuries were included in the study. After at least 3 months of follow‐up, six patients who were lost to follow‐up and four patients who underwent meniscus repair were excluded. Eventually, 25 patients who were diagnosed with ACL rupture and grade I–II MCL injury underwent SAR group. Sixteen patients who were diagnosed with ACL rupture and grade III MCL injury received simultaneous ACL and MCL reconstruction via ipsilateral single hamstring tendon autografts (SAMR group).
FIGURE 5.
The flow of participants throughout the research.
The demographic data of the patients are presented in Table 1. No significant differences were observed between the groups with respect to age, sex, duration of injury, surgical site, or simultaneous meniscus injury. There was no significant difference in meniscal injury between the groups. These patients had undergone partial meniscectomy if necessary. The mean durations of injury were 20.28 and 20.19 weeks, which were greater than 3 months, which was our definition of chronic injury. With respect to injury type, sporting activities were the main reason for ACL and MCL injuries in both groups. Regarding the MCL injury site in the SAR group, 22 of 25 lesions (88%) were classified as type I (located at the femoral attachment site), and 3 (12%) were classified as type III (the lesion extended from the femoral attachment site above the joint line). There were no type II injuries (lesions located at the tibial insertion site). In the SAMR group, 10 of 16 lesions (62.5%) were type I, 1 (6.3%) was type II, and 5 (31.3%) were type III. The proportion of patients in the SAMR group tended to be greater than that in the SAR group, but the difference was not statistically significant.
TABLE 1.
Demographic data of patients. a
| SAR | SAMR | p value | |
|---|---|---|---|
| Number of cases | 25 | 16 | |
| Age (years) | 35.16 ± 8.02 | 34.25 ± 8.51 | 0.746 b |
| Gender (Male/Female) | 17/8 | 11/5 | > 0.999 c |
| Surgical site (L't/R't) | 12/13 | 8/8 | > 0.999 c |
| Duration of injury (weeks) | 20.28 ± 1.77 | 20.19 ± 1.68 | 0.899 b |
| Meniscus injury (positive) | 17 (68%) | 11 (68.8%) | 0.960 c |
| Type of injury | 1 d | ||
| Sports | 19 (76%) | 12 (75%) | |
| Traffic accident | 5 (20%) | 4 (25%) | |
| Work‐related | 1 (4%) | 0 | |
| MCL injury site | 0.07 d | ||
| Type I | 22 (88%) | 10 (62.5%) | |
| Type II | 0 | 1 (6.3%) | |
| Type III | 3 (12%) | 5 (31.3%) |
Continuous values are documented as mean and standard deviation unless there is other indication.
Independent t test.
Chi‐square test.
Fisher's exact test.
3.2. Physical Exams
The results of the physical exams are presented in Table 2. We deemed the results of the Lachman test and valgus stress test to be continuous variables. For instance, Grade I was given a score of 1. The mean preoperative Lachman test score of the SAR group was 2.38 ± 0.39, whereas that of the SAMR group was 2.41 ± 0.31. No significant difference was observed in the results of the preoperative Lachman test between the groups. We evaluated the tests after at least 1 year of follow‐up at the outpatient department. The mean postoperative Lachman test score of the SAR group was 0.98 ± 0.38, whereas that of the SAMR group was 0.91 ± 0.2. Moreover, no significant difference was observed between the two groups at the 1‐year follow‐up.
TABLE 2.
Physical exams.
| SAR | SAMR | p value | ||
|---|---|---|---|---|
| Anterior knee pain | 6 (24%) | 4 (25%) | 0.942 a | |
| ROM | Flexion pre‐op | 125.20 ± 6.03 | 128.08 ± 4.35 | 0.108 b |
| Flexion post‐op | 137.40 ± 3.27 | 138.08 ± 3.84 | 0.385 b | |
| Extension pre–op | −0.28 ± 1.77 | −0.69 ± 1.44 | 0.302 b | |
| Extension post–op | −1.56 ± 1.5 | −1.38 ± 1.33 | 0.465 b | |
| Lachman test | Pre‐op | 2.38 ± 0.39 | 2.41 ± 0.31 | 0.227 b |
| Post‐op | 0.98 ± 0.38 | 0.91 ± 0.2 | 0.606 b | |
| Valgus stress test (30°) | Pre‐op | 1.40 ± 0.5 | 1.81 ± 0.4 | 0.390 b |
| Post‐op | 0.64 ± 0.64 | 0.75 ± 0.68 | 0.603 b | |
| Valgus stress test (0°) | Pre‐op | 0.32 ± 0.48 | 1.63 ± 0.5 | < 0.001 b |
| Post‐op | 0.12 ± 0.33 | 0.31 ± 0.48 | 0.105 b |
Chi‐square test.
Independent t test.
The mean score of the preoperative valgus stress test at 30° in the SAR group was 1.40 ± 0.5, whereas that in the SAMR group was 1.81 ± 0.4. No significant difference was observed in the results of the preoperative valgus stress test at 30° between the groups. The mean score of the preoperative valgus stress test at 0° in the SAR group was 0.32 ± 0.48, whereas that in the SAMR group was 1.63 ± 0.5. A significant difference was observed in the results of the preoperative valgus stress test at 0° between the groups (p = 0.0001). We evaluated the tests after at least 1 year of follow‐up at the outpatient department. The mean score of the preoperative valgus stress test at 30° in the SAR group was 0.12 ± 0.33, whereas that in the SAMR group was 0.31 ± 0.48. Moreover, no significant difference was observed between the two groups at the 1‐year follow‐up (p = 0.1053).
The knee ROM was measured and recorded before the operation and at least 1 year after the operation. The degrees of flexion and extension of the injured knee are presented in Table 2. The preoperative degree of knee flexion in the SAR group was 125.20 ± 6.03, whereas that in the SAMR group was 128.08 ± 4.35. No significant difference was observed between the groups. The postoperative score of the SAR group was 137.79 ± 3.06, whereas that of the SAMR group was 138.59 ± 4.06. There was no statistical significance. The preoperative degree of knee extension in the SAR group was −1.56 ± 1.5, whereas that in the SAMR group was −1.38 ± 1.33. The negative value represents hyperextending over the neutral point. There was no significant difference between the groups. Furthermore, the postoperative value of the SAR group was −0.28 ± 1.77, whereas that of the SAMR group was −0.69 ± 1.44. No significant difference was observed.
3.3. Functional Scores
The International Knee Documentation Committee (IKDC) score, the Single Assessment Numeric Evaluation (SANE) score and the Tegner activity scale score were evaluated before and 2 years after the operation. The results of these functional scores are shown in Table 3. Before the operation, the mean total IKDC score of the SAR group was 47.76, whereas that of the SAMR group was 49.0. No significant difference was observed. Postoperatively, the mean total IKDC score of the SAR group was 70.52 ± 7.62, and that of the CSIS group was 71.44 ± 5.66. No significant difference was observed between the two groups (p = 0.2331). For the SANE score, the postoperative score in the SAR group was 78.8 ± 11.75, and that in the SAMR group was 77.5 ± 13.90. No significant difference was observed between the two groups (p = 0.4488). For the Tegner activity level scale, the preoperative mean score of the SAR group was 3.0 ± 1.38, and that of the SAMR group was 3.5 ± 1.46. No significant difference was observed (p = 0.7918). Postoperatively, the mean score of the SAR group was 4.0 ± 1.35, and that of the SAMR group was 4.94 ± 2.02. No significant difference was observed between the groups (p = 0.0795).
TABLE 3.
Functional scores.
| SAR | SAMR | p value | ||
|---|---|---|---|---|
| SANE | 78.8 ± 11.75 | 77.5 ± 13.90 | 0.449 a | |
| Tegner activity score | Pre‐op | 3.0 ± 1.38 | 3.5 ± 1.46 | 0.792 a |
| Post‐op | 4.0 ± 1.35 | 4.94 ± 2.02 | 0.080 a | |
| IKDC score | Pre‐op | 47.76 ± 8.07 | 49.0 ± 7.90 | 0.955 a |
| Post‐op | 70.52 ± 7.62 | 71.44 ± 5.66 | 0.233 a |
Independent t test.
Comparison of functional scores and clinical outcomes before and after the operation between two groups are shown in Table 4. The difference in the Tegner activity score was 1 ± 0.57 (p < 0.001) in the SAR group and 1.43 ± 0.89 (p < 0.001) in the SAMR group. The IKDC score in the SAMR group was 23.95 ± 11.21 (p < 0.001), whereas that in the SAR group was 22.44 ± 5.07 (p < 0.001). Statistical significance was observed. For the clinical outcomes, the differences in the ROM, valgus stress test and Lachman test score within the groups were analyzed. The difference in knee flexion was 12.2 ± 5.42 (p < 0.001) in the SAR group, whereas it was 10.31 ± 2.87 (p < 0.001) in the SAMR group. Furthermore, the difference in knee extension was 1.28 ± 1.97 (p < 0.001) in the SAR group, whereas it was 0.81 ± 1.17 (p = 0.0139) in the SAMR group. A significant difference was observed between the two groups. The difference in the Lachman test score in the SAR group was −1.42 ± 0.55 (p < 0.001), whereas that in the SAMR group was −1.59 ± 0.20 (p < 0.001). Statistical significance was observed in both groups. In the valgus stress test, the difference in the score at 30° was −0.76 ± 0.52 (p < 0.001) in the SAR group, whereas it was −1.06 ± 0.57 (p < 0.001) in the SAMR group. Significant differences were observed between the two groups. The difference in the score at 0° was −0.2 ± 0.41 (p = 0.02) in the SAR group, whereas it was −1.31 ± 0.60 (p < 0.001) in the SAMR group. Significant differences were observed between the two groups.
TABLE 4.
Difference in clinical outcomes before and after the operation.
| SAR | p value | SAMR | p value | |
|---|---|---|---|---|
| ROM flexion a diff. | 12.2 ± 5.42 | < 0.0001 | 10.31 ± 2.87 | < 0.001 b |
| ROM extension a diff. | −1.28 ± 1.97 | 0.0034 | −0.81 ± 1.17 | 0.014 b |
| Lachman test a diff. | −1.42 ± 0.55 | < 0.0001 | −1.59 ± 0.20 | < 0.001 b |
| Valgus stress test (30°) a diff. | −0.76 ± 0.52 | < 0.0001 | −1.06 ± 0.57 | < 0.001 b |
| Valgus stress test (0°) a diff. | −0.2 ± 0.41 | 0.022 | −1.31 ± 0.60 | < 0.001 b |
| Tegner a diff. | 1 ± 0.57 | < 0.0001 | 1.43 ± 0.89 | < 0.001 b |
| IKDC a diff. | 23.95 ± 11.21 | < 0.0001 | 22.44 ± 5.07 | < 0.001 b |
diff. = difference.
Paired t test.
3.4. MRI Evaluation of the Graft
We evaluated the SI of the ACL and PCL via T2‐weighted sagittal view and the MCL via T2‐weighted coronal view via MRI and graded the results on the above scale. The graft SI on MRI was divided into two categories: Grade I and Grade II–III. However, none of the patients' grafts were grade III. We present the results in Table 5. With respect to the ACL graft SI, 18 patients in the SAR group were grade I, and 7 patients were grade II–III, whereas 11 patients in the SAMR group were grade I, and 5 patients were grade II–III. No significant difference was observed between the groups (p > 0.999). With respect to MCL graft SI, 10 patients were grade I, and 4 patients were grade II–III in the SAMR group. The results of the MRI findings of the MCL graft SI and knee stability measurements are presented in Table 6. We found no statistically significant associations (p < 0.05) between the MRI of MCL graft SI and the knee stability measurements, including ROM, functional score, knee laxity, and valgus instability.
TABLE 5.
Graded of MRI Findings of graft SI.
| Graft | MRI SI | p value | ||
|---|---|---|---|---|
| Grade I | Grade II–III | |||
| SAR | ACL | 18 a (72%) | 7 a (28%) | > 0.999 b |
| SAMR | ACL | 11 a (69%) | 5 a (31%) | |
| MCL | 12 a (75%) | 4 a (25%) | ||
Number of patients.
Fisher's exact test.
TABLE 6.
MRI Findings of MCL graft SI and knee stability measurements.
| Grade I | Grade II–III | p value | |
|---|---|---|---|
| ROM extension | −1.4 ± 1.2 | −1.0 ± 1.2 | 0.528 a |
| ROM flexion | 138.8 ± 4.1 | 77.5 ± 8.3 | 0.650 a |
| Tegner activity | 5.3 ± 2.1 | 4.0 ± 1.0 | 0.410 a |
| SANE | 77.5 ± 14.8 | 77.5 ± 8.3 | 0.884 a |
| IKDC | 71.0 ± 6.0 | 72.8 ± 3.3 | 0.692 a |
| Lachman test | 0.9 ± 0.2 | 1.0 ± 0.0 | 0.529 a |
| Valgus stress test (0°) | 0.9 ± 0.6 | 0.3 ± 0.4 | 0.173 a |
| Valgus stress test (30°) | 0.2 ± 0.4 | 0.8 ± 0.4 | 0.063 a |
Mann–Whitney U test.
4. Discussion
4.1. Highlights of the Study
As the primary objective of this study, we described a novel reconstruction technique for combined chronic ACL and grade III MCL injuries. To the best of our knowledge, this is the first study to introduce and assess simultaneous ACL and MCL reconstruction via a single ipsilateral hamstring autograft. Our results demonstrated improved postoperative outcomes in terms of ROM, functional scores, Lachman test results, and valgus instability in the SAMR group compared with their respective preoperative values.
4.2. Outcomes Between Two Groups
The SAMR group had overall improved postoperative outcomes. When the SAMR group was compared with the SAR group, no significant differences were observed in postoperative ROM, functional scores, Lachman test results, or valgus laxity. These findings suggest that this new reconstruction technique can contribute to the enhancement of persistent valgus instability and knee laxity in patients with severe MCL injury combined with ACL injury.
Furthermore, the valgus stability of the SAR group was superior to that of the SAMR group preoperatively, although there were no differences between the two groups postoperatively. This observation leads us to speculate that patients with combined ACL injury and severe MCL injury can potentially regain knee stability, particularly valgus stability, to a state comparable to that of patients with ACL injury and mild MCL injury.
In terms of evaluating postoperative ACL autograft MRI SI, 72% of patients in the SAR group and 68% of patients in the SAMR group were classified as grade I, which is indicative of a high‐quality graft [29, 31]. This outcome suggests that both groups had equally high‐quality autograft reconstructions, providing evidence that simultaneous reconstruction of the ACL and MCL does not appear to impact the quality of the ACL graft. Moreover, in our study, none of the patients in either group required reoperation within the 2‐year follow‐up period. In a review article by Mowers et al., MCL reconstruction exhibited failure rates ranging from 0% to 14.6% [33]. The reoperation rate following combined ACL and MCL surgery in the study conducted by Westermann et al. was 25% [7]. Importantly, however, failures and reoperations often occur beyond the 2‐year mark, indicating the need for longer follow‐up periods. The association between MRI‐SI unit evaluation and clinical presentation remains a subject of controversy. While some studies have indicated that MRI SI evaluation correlates with knee flexion ROM or healing status, it may not necessarily be linked to knee laxity [30, 34].
In terms of MCL quality, 75% of patients in the SAMR group were classified as grade I, which also implies a high‐quality graft. To the best of our knowledge, this is the first study in English to assess the clinical significance of post‐reconstruction MCL MRI findings. Our findings indicate that different MCL graft MRI SI groups were not correlated with knee laxity or valgus stability. However, the relatively small sample size (n = 16) in our study might be one of the reasons; future studies with larger sample sizes could help address this limitation. Another consideration is the relatively subjective method we employed to evaluate the MRI SI. Future research could implement an objective methodology to assess MCL graft MRI SI [35].
4.3. Our Modified Technique
In the SAMR group, we utilized a single ipsilateral hamstring autograft reconstruction technique. A similar technique was described by Sim et al., which involved the same choice of MCL graft and simultaneous ACL reconstruction [36]. First, the hamstring autograft was harvested and implanted for MCL reconstruction through the same incision. Second, we employed hamstring autografts for both ACL and MCL reconstruction, thereby reducing the risks of failure and infection [19, 20, 37]. Additionally, the utilization of autografts results in lower economic costs [36, 38].
MCL reconstruction techniques can be categorized into different types on the basis of whether both superficial medial collateral ligament (sMCL) and POL reconstructions are performed [39]. Single‐bundle reconstruction indicates that only sMCL reconstruction is carried out, whereas double‐bundle reconstruction indicates that both sMCL and POL reconstructions are performed. The sMCL is characterized by a barbell configuration, a single point of femoral insertion, and two distal tibial insertions. It is the most common rupture location in MCL injuries and plays a pivotal role in restoring native knee biomechanics [40, 41]. On the other hand, the POL is a component of the posteromedial knee complex, serving as the primary restraint to internal rotation and a secondary restraint to valgus deformity between 0° and 30° of knee flexion. In our study, the MCL rupture sites in most patients were primarily type I or type II proximal sMCLs, with severe injury to the POL sparing. The reconstruction of the sMCL using the gracilis graft involved securing it to the remaining fibers of the ruptured MCL, along with advanced repair at the tibial site. A recent study by Hinz et al. demonstrated simultaneous ACL and MCL reconstruction with hamstring and peroneal longus split autografts. The results were satisfying and there was no significant impairment to the ankle. Yet, the technique requires additional donor site which could increase risk and damage to the patients [42]. Our technique offers the advantage of allowing easy implantation of the free autograft into the correct anatomical position to replicate the course of the native sMCL [39].
4.4. Algorithm for Simultaneous ACL and MCL Injuries
On the basis of our study, we developed an algorithm for patients with ACL injury and possible concurrent MCL injury. Initially, a comprehensive imaging and physical examination should be conducted. If a diagnosis of combined ACL and MCL injury is confirmed, conservative management with a knee brace could be considered initially, as spontaneous healing of the MCL is possible. After a three‐month follow‐up, a re‐evaluation of the MCL condition was carried out. In cases of ACL rupture and severe MCL rupture, reconstruction via our technique as a one‐stage surgery is recommended. Patients who undergo this approach can achieve knee stability comparable to that of patients with mild MCL injuries. Therefore, we believe that the waiting period outlined above is justifiable, as it relieves the surgical burden on patients with mild injuries and postponing reconstruction does not adversely affect treatment outcomes.
The ideal timeframe for surgical intervention in patients with ACL and MCL combined injuries is still controversial [4]. Delayed ACL reconstruction until the knee ROM, quadriceps activation, and knee effusion return to normal seems to benefit the protection of the MCL [43, 44]. However, Harner et al. reported that acute ACL reconstruction (within 3 weeks) with conservative MCL treatment had better subjective and objective knee stability outcomes than delayed ACL reconstruction with conservative MCL treatment [45]. Several studies have recommended similar management algorithms for patients with combined ACL and MCL injuries [8, 46]. We all agree with delayed ACL reconstruction and knee brace treatment with a progressively increasing ROM, but for those who still have knee valgus instability, there is no concurrent reconstruction treatment in the algorithm [46]. Westermann et al. [7] reported that delayed reconstruction of the ACL and MCL did not affect the functional scores. Large‐scale studies on the best timeframe for concurrent ACL and MCL reconstruction are lacking. With the initial assistance of a knee brace, although delayed surgery is beneficial for patients with combined MCL and ACL injuries, further studies on the timing of simultaneous reconstruction could be conducted in the future.
4.5. Limitations and Strengths
This study possesses several strengths. Firstly, this is the first study showcasing simultaneous reconstruction of ACL and MCL with single hamstring autograft to the best of our knowledge. Second, we conducted MRI during the follow‐up to prove the quality of the grafts. Nevertheless, this study had several limitations. First, the relatively short period of follow‐up as well as the non‐randomized design may cause bias to the study. Second, due to the high self‐healing rate of MCL after the first knee brace in most patients with acute simultaneous ACL and MCL injuries, the number of combined MCL and ACL cases was limited to 41, with only 16 patients having severe MCL injuries. A future study with a larger sample size would enhance the level of evidence. Moreover, more objective evaluation methods, such as Telos stress radiography and the use of KT‐1000 in valgus stress tests and Lachman's tests, were not presented in our study. However, our focus was on postoperative MR images and functional scores. Another study has shown that the KT‐1000 arthrometer should be used only as a diagnostic tool since it is not appropriate for use as an outcome instrument [47]. Lastly, while MRI SI provides an objective assessment, we employed a subjective grading method. In future studies, considerations could be given to incorporating volume or average SI measurements [35].
5. Conclusion
In the present study, we outlined a new method involving the use of a single hamstring autograft for simultaneous reconstruction of the ACL and MCL. This surgical approach can result in similar knee stability, MRI findings, and functional outcomes as those of patients who have low‐grade MCL injuries and undergo a single ACL reconstruction. Nevertheless, the quality of our study is still limited; therefore, studies with larger sample sizes and long‐term follow‐up periods are necessary to generate more solid conclusions for further application in the future.
Author Contributions
All authors had full access to the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. All authors have read and approved the final manuscript. Conceptualization: Pei‐Wei Weng. Methodology: Po‐Jen Lai and Er‐Yuan Chuang. Investigation: Cheng‐Yi Lin. Formal analysis: Wen‐Pei Chang, Cheng‐Yi Lin, and Po‐Jen Lai. Resources: Ming‐Ta Yang and Tan Cheng Aun. Writing – original draft: Cheng‐Yi Lin. Writing – review and editing: Po‐Jen Lai, Pei‐Wei Weng. Visualization: Cheng‐Yi Lin. Supervision: Pei‐Wei Weng.
Funding
The authors have nothing to report.
Ethics Statement
Ethical approval for this study was granted by the Joint Institutional Review Board of Taipei Medical University (TMU‐JIRB N202312103).
Consent
All participants provided informed consent, and patient confidentiality has been maintained in accordance with ethical standards.
Conflicts of Interest
The authors declare no conflicts of interest in the conduct and reporting of this research.
Lin C.‐Y., Lai P.‐J., Yang M.‐T., et al., “Delayed Simultaneous Reconstruction of the ACL and MCL Using Ipsilateral Single Hamstring Tendon Autograft With A Modified Technique,” Orthopaedic Surgery 18, no. 1 (2026): 126–137, 10.1111/os.70234.
Data Availability Statement
This study adheres to guidelines for data transparency and reproducibility. All relevant data supporting the findings of this research are available upon request from the corresponding author.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
This study adheres to guidelines for data transparency and reproducibility. All relevant data supporting the findings of this research are available upon request from the corresponding author.