Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

Effects of clamshell exercises in terminal extension lag after ACL reconstruction

BACKGROUND

Terminal extension lag (TEL) is common following anterior cruciate ligament reconstruction (ACLR). Clamshell exercises have been suggested as a potential intervention to address TEL, but limited research has been conducted in this area.

OBJECTIVE

This study aimed to determine the effects of Clamshell exercises in terminal extension lag after anterior cruciate ligament reconstruction.

METHODS

This randomized controlled trial included 40 participants with a history of ACLR between 1 and 3 years prior. Participants were randomly assigned to either the experimental group (Group A) or the control group (Group B). Group A received conventional exercises along with isolated hip strengthening rehabilitation, while Group B received conventional exercises without specific hip strengthening. The primary outcomes were pain levels (Numeric Pain Rating Scale), knee function (International Knee Documentation Committee scores, (IKDC)), range of motions (goniometer) and strength (sphygmomanometer).

RESULTS

In between the group comparison shows that all outcome measures (NPRS, IKDC, Goniometer, Sphygmomanometer) show significant results (p < 0.05). Within-group comparisons (paired sample t-test) show that there was a significant difference (p < 0.05) in all outcome measures of both groups.

CONCLUSION

The addition of Clamshell exercises to the rehabilitation program resulted in a significantly greater reduction in TEL compared to the control group. These findings suggest that Clamshell exercises were found to be an effective intervention for addressing TEL after ACLR.

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant-preserving anterior cruciate ligament reconstruction

PURPOSE

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured.

RESULTS

The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6 mm and 9.3 ± 1.7 mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect.

CONCLUSIONS

The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

Various Definitions of Failure Are Used in Studies of Patients Who Underwent Anterior Cruciate Ligament Reconstruction

Purpose

To conduct a literature review to assess the definitions of anterior cruciate ligament reconstruction (ACLR) failure used throughout the orthopaedic literature.

Methods

A systematic search of Embase, Ovid Medline, SPORTDiscus, and Web of Science was conducted by a university librarian to identity level I-IV clinical studies on ACLR failure. Inclusion criteria consisted of patients who underwent ACLR and included a definition of failure of ACLR. Patients who underwent anterior cruciate ligament (ACL) repairs, animal/cadaver studies, review studies, non-English language articles, and non-full text articles were excluded. Failure data were extracted from each study and categorized. Other data that were extracted included follow-up time after ACLR, failure reoperation rate, and failure reoperation procedure. Descriptive statistics was used to analyze the data.

Results

Out of 2,775 studies, 104 (3.75%) met inclusion criteria and were analyzed in this review. The most common definition of ACLR failure included the use of a physical examination, specifically Lachman's test (21/104 [20.2%]), anterior laxity assessment, or a Pivot-Shift test (24/104 [35.2%]) or undergoing or requiring revision ACLR (39/104 [37.5%]). Although some studies used quantitative tests or imaging to help define "failure," others simply defined it as graft rerupture that was otherwise not defined (22/104 [22.5%]). Other common definitions included: the use of imaging (magnetic resonance imaging/radiographs) to confirm graft re-rupture (37/104 [35.6%]), patient-reported outcomes (recurrent instability)/patient reported outcomes measures (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Tegner) (18/104 [17.3%]), and the use of an arthrometer (KT-1000/2000, Rollimeter, or Kneelax) (17/104 [16.3%]). The least common definitions included graft failure or rerupture confirmed by arthroscopy (13/104 [12.5%]) and nonrevision surgery (2/104 [1.0%]). The failure rate of this procedure ranged from 0% to 100% depending on the definition of "failure."

Conclusion

In this study, we found that a variety of definitions of failure are used among studies published in the orthopaedic literature. The most common criteria for failure of ACLR were the results of physical examination tests (35%), the need for undergoing a revision ACLR (36%), and the use of imaging to diagnose the failure (34%). About 17% of studies included in this review used patient-reported outcomes, specifically recurrent instability, or PROMs (IKDC, KOOS, Tegner) in their assessment of failure of ACLR. The least used definitions of "failure" of ACLR included nonrevision ACLR surgery (2%). Although some studies used similar tests or categories in their definition of failure, there were a variety of score and grade cutoff points between them.

Level of Evidence

Level IV, systematic review of Level II-IV studies.

A fast, easy and reliable method for hamstrings graft size prediction in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to describe and validate a simple and reliable method to pre-operatively predict the size of the ACL graft in the double strand technique with autologous semitendinosus-gracilis tendons on the same MRI used for ACL rupture diagnosis.

METHODS

The study included 92 patients, with a median age of 31 years (IQR 26-41 years), 73/92 (79%) of whom were males. All patients that underwent an ACL reconstruction with doubled ST + GT between 2017 and 2022 were counted in the study.

RESULTS

Overall, the median predicted graft diameter from MR imaging was similar to the actual graft diameter with no significant differences (n.s.). Regarding the comparison between predicted and actual graft size, concordance was 78/92 (85%, 95% CI 76-91%), with κ = 0.797 which corresponds to a level of agreement defined as "Strong". Tendon sizes calculated on pre-operative MRI were evaluated both with intra-observer and inter-observer reliability demonstrating a statistically reproducible method. The predicted graft was then compared to the reported one with a statistically significant reliability found.

CONCLUSION

This study can help the surgeons to perform a fast pre-operative planning of an ACL reconstruction for graft selection. If the planned graft with ST and GT is smaller than 8 mm, the clinician can decide to switch to a different type of graft or plan a different graft preparing technique and, therefore, reduce the risk of post-operative ligament re-rupture. The method proposed is reliable and reproducible. The major strength of the planning technique proposed is that it relies on data that are already available for the clinician before surgery, without the need of further analysis.

LEVEL OF EVIDENCE

IV.

Postoperative Tunnel Widening, Elliptical Aperture Shape, and No Preservation of the Remnant Are Related to the Tendon Graft-Bone Tunnel Gap Formation at the Intra-Articular Aperture After Double-Bundle Anterior Cruciate Ligament Reconstruction

Purpose

To examine the bone-tendon healing at the posterolateral (PL) femoral tunnel aperture by second-look arthroscopy after double-bundle anterior cruciate ligament reconstruction (ACLR), and assess the risk factors for impaired healing at the tendon-bone interface.

Methods

A consecutive series of knees undergoing primary double-bundle ACLR using hamstring tendon autografts were enrolled in the study. The exclusion criteria were as follows: previous knee surgeries, concomitant ligamentous and osseous procedures, and a lack of second-look arthroscopy or postoperative computed tomography data for the analysis. Cases in which a gap was identified between the graft and tunnel aperture during the second-look arthroscopic examination were classified as the gap formation (GF) group. A multivariate logistic regression analysis was performed to assess the relationship between the GF and variables that may determine prognosis.

Results

A total of 54 knees that met the inclusion/exclusion criteria were included in the study. Second-look arthroscopy revealed the GF at the PL aperture in 22 of the 54 knees (40%). The time period from surgery to arthroscopy averaged 16 months. In the multivariate logistic regression analysis, the percentage tunnel widening at 1 year on computed tomography (odds ratio, 10.4; 95% confidence interval [CI] 1.56-69.2), ellipticity of the tunnel aperture (odds ratio, 3.57; 95% CI, 0.79-16.11), and no ACL remnant preservation (odds ratio, 5.99; 95% CI, 1.23-29.06) were identified as prognostic factors significantly related to graft-bone tunnel GF.

Conclusions

Second-look arthroscopy revealed GF at the PL graft-bone tunnel interface in 40% of the knees after double-bundle ACLR. Incomplete healing of the interface, as evidenced by a graft-bone gap at the tunnel aperture, was associated with tunnel widening 1-year postsurgery, an elliptical aperture shape, and no preservation of the ACL remnant.

Level of Evidence

Ⅲ, retrospective case-control study.

ACL stump and ACL femoral landmarks are equally reliable in ACL reconstruction for assisting ACL femoral tunnel positioning

PURPOSE

This study aimed to comparatively evaluate the accuracy of femoral tunnel positioning after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction performed with the remnant preservation (RP) technique versus the non-remnant preservation (NRP) technique.

METHODS

A retrospective review of 145 patients who underwent ACL reconstruction from May 2020 to May 2022 were performed in this single-surgeon study. A total of 120 patients met the inclusion criteria and were allocated into two groups according to the surgical technique (i.e. RP group and NRP group). The relative location of the femoral tunnel in the lateral condyle was evaluated as a percentage using a standardized grid system on the three-dimensional computed tomography (3D-CT) image. The accuracy and precision of the RP group were assessed based on published anatomical data in direct comparison with the NRP group.

RESULTS

According to the surgical procedure, 57 of the 120 patients included were allocated into the RP group, and 63 into the NRP group. Significant differences were observed between the two groups in terms of tunnel position (posterior-to-distal (PD): 28.4 ± 5.4% (RP) vs. 31.8 ± 5.3% (NRP); P = 0.01), (anterior-to-posterior (AP): 32.6 ± 7.7% (RP) vs. 38.8 ± 7.7% (NRP); P = 0.00), while no significant differences were found in terms of the accuracy (8.6% (RP) vs. 8.9% (NRP); n.s) and precision (4.4% (RP) vs. 5.6% (NRP); n.s) of femoral tunnel positioning between the two groups.

CONCLUSIONS

From this single-surgeon study, it was concluded that there were no differences in the creation of ACL femoral tunnel between the RP technique and the non-remnant preserving technique. Meanwhile, the RP technique would not sacrifice the ideal position of the femoral tunnel and is able to retain the possible benefits of the ACL stump.

LEVEL OF EVIDENCE

Level III.

Effect of a new remnant-preserving technique with anatomical double-bundle anterior cruciate ligament reconstruction on MRI-based graft maturity: a comparison cohort study

PURPOSE

To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI).

METHODS

A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables.

RESULTS

In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels.

CONCLUSION

The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity.

LEVEL OF EVIDENCE

Level III.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

Background

Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two.

Method

We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented.

Result

Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = −0.13, 95%CI (−0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (−0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = −0.22, 95%CI (−0.42, −0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = −0.66, 95%CI (−1.08, −0.23), P = 0.002 < 0.05].

Conclusion

This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

A new remnant preservation technique reduces bone tunnel enlargement after anatomic double-bundle anterior cruciate ligament reconstruction

PURPOSE

To investigate the effect of a new remnant preservation technique with a focus on remnant continuity on postoperative femoral and tibial tunnel enlargement after anatomical double-bundle anterior cruciate ligament reconstruction (ACLR).

METHODS

A total of 150 knees were divided into three groups: Preservation Group (Group P: 49 knees), wherein the remnant continuity remained after tunnel creation; Resection Group (Group R: 47 knees), wherein the remaining remnant was resected, and Absent Group (Group A: 54 knees), wherein the remnant had no femoral attachment before tunnel creation. In Group P, the remnant maintained continuity, and the anteromedial (AM) and posterolateral (PL) bundles were positioned anterior and posterior to the remnant, respectively. Computed tomographic scans were performed at 1 week and 1 year after surgery, and the cross-sectional area of each tunnel aperture was measured. Tunnel enlargement was compared among the three groups by one-way analysis of variance (ANOVA) and the Bonferroni test. Univariate and multivariate logistic analyses were performed to identify the risk factors for tunnel enlargement in demographic and radiographic data.

RESULT

For femoral AM tunnels, the tunnel enlargement of Group P was significantly smaller than Groups R and A (p < 0.001), femoral PL (p < 0.001 vs. R and A), tibial AM (p < 0.001 vs. R, 0.002 vs. A), and tibial PL (p < 0.001 vs. R, 0.002 vs. A). There was no significant difference between Groups R and A. Multivariate logistic analysis showed that remnant preservation was a significant factor in reducing tunnel enlargement in the femoral AM, femoral PL, tibial AM, and tibial PL.

CONCLUSION

The new remnant-preserving anatomical double-bundle ACLR, which preserves the continuity of the remnant, prevented all bone tunnel enlargement at 1 year postoperatively.

LEVEL OF EVIDENCE

Level III.