Tendon graft through the coracoid tunnel versus under the coracoid for coracoclavicular/acromioclavicular reconstruction shows no difference in radiographic or patient-reported outcomes.

INTRODUCTION: The purpose of this prospective study was to report the outcomes of two different methods in CC and AC reconstruction for the treatment of AC separation using a tendon graft and knot-hiding titanium clavicular implant. MATERIALS AND METHODS: Twenty-seven patients with Rockwood grade III and V acromioclavicular (AC) separations were randomized into two groups. The primary outcome was whether taking the tendon graft through the coracoid risked a fracture. The following were secondary outcomes: follow-up of clavicular wound healing and Nottingham Clavicle score, Constant score, and Simple Shoulder Test results obtained preoperatively and 24 months postoperatively. The anteroposterior radiographic change between the clavicular and coracoid cortexes and the clavicular tunnel diameter was measured postoperatively and 24 months postoperatively. General patient satisfaction with the outcome (poor, fair, good, or excellent) was assessed 2 years postoperatively. RESULTS: No coracoid fractures were detected. No issues in clavicular wound healing were detected. The mean Nottingham Clavicle score increased from a preoperative mean of 42.42 ± 13.42 to 95.31 ± 14.20 (P < 0.00). The Constant score increased from a preoperative mean of 50.81 ± 17.77 to 96.42 ± 11.51 (P < 0.001). The Simple Shoulder Test score increased from a preoperative mean of 7.50 ± 2.45 to 11.77 ± 1.18 (P < 0.001). The changes were significant. The coracoclavicular distance increased from 11.88 ± 4.00 to 14.19 ± 4.71 mm (P = 0.001), which was significant. The clavicular drill hole diameter increased from 5.5 to a mean of 8.00 ± 0.75 mm. General patient satisfaction was excellent. CONCLUSIONS: There were no significant differences between the two groups. There were no implant related complications in the clavicular wound healing. The results support the notion that good results are achieved by reconstructing both the CC and AC ligaments with a tendon graft. STUDY REGISTRATION: This clinical trial was registered on Clinicaltrials.gov.

Comparison of the Clinical Outcomes between All-inside and Standard Technique in Anterior Cruciate Ligament Reconstruction with 6-strand Hamstring Tendon Autograft.

OBJECTIVE: All-inside and standard techniques with 4-strand hamstrings graft have been widely used in anterior cruciate ligament (ACL) reconstruction. However, the graft diameter of less than 8 mm will significantly increase the rate of surgical failure, and the 6-strand graft can solve this problem. The purpose of this study is to compare all-inside ACL reconstruction using suspensory cortical button fixation on both tibia and femur with standard ACL reconstruction using suspensory femoral fixation and a bioabsorbable tibial interference screw with a 6-strand hamstring tendon autograft in postoperative clinical outcomes. METHODS: From January 2020 to December 2020, 48 patients performed ACL reconstruction were divided into the all-side group and the standard group according to the different surgical techniques. Magnetic resonance imaging (MRI) and subjective function scores was used to assess clinical outcomes at least 24 months following ACL reconstruction. MRI was used to measure the value of bone tunnel widening in articular and middle portions. Subjective function scores included the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Society Score (KSS) for pain and function, and KT-1000. The t-test was used assuming the distribution of the patients which follows the normal distribution and we used non-parametric tests if these two conditions were not satisfied. RESULTS: At the final follow-up, there were 22 patients in the all-inside group and 24 patients in the standard group. No significant differences were found with respect to femoral tunnel widening and subjective function scores. However, a significant increase in tibial tunnel widening was found in the middle portion of the standard group (2.25 ± 0.74) compared to the all-inside group (0.76 ± 0.24) (p < 0.01) and also in the articular portion of the standard group (2.07 ± 0.77) compared to the all-inside group (1.52 ± 0.54) (p = 0.02). In addition, the value of the KT-1000 was 1.81 ± 0.45 for the all-inside group and 2.12 ± 0.44 in the standard group (p = 0.016). CONCLUSION: The objective stability of the knee was relatively better in the all-inside group than in the standard group. And tunnel widening after ACL reconstruction was significantly greater in the standard technique when compared to the all-inside technique on the tibia side.

Clavicular tunnel widening after coracoclavicular stabilization surgery: a systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis aimed to (1) estimate the prevalence of clavicular tunnel widening (TW) after coracoclavicular stabilization surgery and its risk factors and (2) assess whether TW is correlated with clavicle fracture or loss of reduction of the acromioclavicular joint (ACJ). METHODS: In January 2023, 3 electronic databases were searched to collect data on postoperative clavicular TW, its prevalence, magnitude, and correlation with fracture and ACJ loss of reduction. Studies were classified according to the time of surgical intervention, and the clavicular tunnels were categorized by their anatomic location. Mean differences were calculated using a DerSimonian-Laird random-effects model, while binomial outcomes were pooled using the Freeman-Tukey double arcsine transformation. Univariate and multivariate meta-regression analyses were performed to determine the effect of several variables on the proportion of cases with TW. RESULTS: Fifteen studies (418 shoulders) were included. At the final follow-up, evidence of clavicular TW was found in 70% (95% confidence interval [CI]: 70%-87%; I2 = 89%) of 221 shoulders. Surgeries in acute cases had a lower prevalence of TW (52%) compared to chronic cases (71%) (P < .001). Significant TW was found in the central tunnel (3.2 mm; 95% CI: 1.8-4.6 mm; P < .001; I2 = 72%) for acute injuries and in the medial (1.2 mm; 95% CI: 0.7-1.7 mm; P < .001; I2 = 77%) and lateral (1.5 mm; 95% CI: 0.7-2.3 mm; P < .001; I2 = 77%) tunnels for chronic cases. Single central-tunnel techniques were positively associated with the prevalence of TW (P = .046), while biotenodesis screw fixation was associated with a lower prevalence (P = .004) in chronic cases. Reconstruction of the ACJ ligament complex with tendon grafts or sutures was associated with a higher prevalence of TW (P < .001). Drill sizes between 2.5 and 5 mm were significantly associated with a lower prevalence of TW, regardless of injury chronicity (P = .012). No correlation was found between TW and the loss of ACJ reduction or clavicle fractures. CONCLUSIONS: This systematic review and meta-analysis explored TW occurrence following coracoclavicular stabilization surgery. TW was observed in 70% of patients at final follow-up, with a higher prevalence in chronic than in acute cases. Modifiable surgical variables, such as single-tunnel tendon graft constructs for acute or chronic injuries and knotted graft procedures for chronic injuries, were significantly associated with TW. Furthermore, the prevalence of TW increased with concomitant surgical treatment of the ACJ ligament complex, and decreased with drill sizes between 2.5 and 5 mm, regardless of lesion chronicity. These surgical variables should be considered when establishing transosseous tunnels for coracoclavicular stabilization. Clavicle fractures and TW mechanisms require further investigation.

Cartilage fragments combined with BMSCs-Derived exosomes can promote tendon-bone healing after ACL reconstruction.

Anterior cruciate ligament reconstruction (ACLR) often fails due to the inability of tendon-bone integration to regenerate normal tissues and formation of fibrous scar tissues in the tendon-bone interface. Cartilage fragments and exosomes derived from bone mesenchymal stromal cells (BMSCs-Exos) can enhance enthesis healing. Nevertheless, the effects on the tendon-bone healing of ACLR remain unknown. This study found that BMSCs-Exos can promote the proliferation of chondrocytes in cartilage fragments, and activated the expression of chondro-related genes SOX9 and Aggrecan. The optimal effect concentration was 1012 events/uL. Besides, BMSCs-Exos could significantly upregulated the expression of BMP7 and Smad5 in cartilage fragments, and further enhanced the expression of chondrogenic genes. Moreover, this study established a rat model of ACLR and implanted the BMSCs-Exos/cartilage fragment complex into the femoral bone tunnel. Results demonstrated that the mean diameters of the femoral bone tunnels were significantly smaller in the BE-CF group than those in the CF group (p = 0.038) and control group (p = 0.007) at 8 weeks after surgery. Besides, more new bone formation was observed in the femoral tunnels in the BE-CF group, as demonstrated by a larger BV/TV ratio based on the reconstructed CT scans. Histological results also revealed the regeneration of tendon-bone structures, especially fibrocartilage. Thus, these findings provide a promising result that BMSCs-Exos/cartilage fragment complex can prevent the enlargement of bone tunnel and promote tendon-bone healing after ACLR, which may have resulted from the regulation of the BMP7/Smad5 signaling axis.

Serial change of femoral and tibial tunnel width after anterior cruciate ligament reconstruction with allograft.

PURPOSE: To investigate progressive tunnel widening and its correlation with postoperative outcomes after anterior cruciate ligament (ACL) reconstruction using allografts. METHODS: Sixty-five patients who underwent ACL reconstruction using a tibialis anterior allograft between 2015 and 2017 were enrolled. Femoral and tibial tunnel widths were measured on anteroposterior (AP) and lateral radiographs immediately and at 3, 6, 12, and 24 months postoperatively. Average femoral and tibial tunnel widths in AP and lateral views were calculated at three different measurement points. Tunnel widening was calculated as the difference in tunnel width immediately and 2 years postoperatively. The correlation between tunnel widening and the postoperative results was analysed. RESULTS: Tunnel width changes between immediate and 2 years postoperatively were as follows, in AP and lateral views, respectively: femur, 3.0 mm ± 1.5 mm and 2.4 mm ± 1.4 mm; and tibia, 2.8 mm ± 1.4 mm and 2.9 mm ± 1.5 mm. Femoral tunnel widths significantly increased until 1 year, but not from 1 to 2 years postoperatively. Tibial tunnel width significantly increased until 2 years postoperatively. In all tunnels, the increments in tunnel widening decreased over time. Increased knee laxity significantly correlated with greater femoral tunnel widening in AP (r = 0.346, P = 0.006) and lateral views (r = 0.261, P = 0.049). CONCLUSION: Femoral tunnel widths gradually increased until 1 year postoperatively, and tibial tunnel widths increased until 2 years after ACL reconstruction with allografts. The tunnel widening rate gradually decreased over time. Femoral tunnel widening of 3.7 mm and 3.2 mm on AP and lateral views, respectively, were the cut-off values for postoperative knee laxity. LEVEL OF EVIDENCE: Level III.

Beneficial Effect of Curved Dilator System for Femoral Tunnel Creation in Preventing Femoral Tunnel Widening after Anterior Cruciate Ligament Reconstruction.

Backgrounds and objectives: A prevalent concern in anterior cruciate ligament (ACL) reconstruction is postoperative tunnel widening. We hypothesized that employing a curved dilator system (CDS) for femoral tunnel creation can reduce this widening after ACL reconstruction compared to the use of a conventional rigid reamer. Materials and Methods: A retrospective study was conducted involving 56 patients who underwent primary ACL reconstruction between January 2012 and July 2013. The patients were categorized into two groups: the reamer group (n = 28) and CDS group (n = 28). All participants were followed up for a minimum of 2 years. Clinical assessment included the Lachman test and pivot-shift test, and the Lysholm score and subjective International Knee Documentation Committee scores. Radiographic evaluation covered the tunnel widening rate, represented as the ratio of the tunnel diameter 2 years after surgery to the tunnel diameter immediately after surgery, and the ratio (A/B) of femoral tunnel (A) to tibial tunnel (B) diameters at respective time points. Results: No significant disparities were found between the two groups in terms of clinical outcomes. However, the reamer group exhibited a greater femoral tunnel widening rate compared to the CDS group (reamer group vs. CDS group: 142.7 ± 22.0% vs. 128.0 ± 19.0% on the anteroposterior (AP) radiograph and 140.8 ± 14.2% vs. 122.9 ± 13.4% on the lateral radiograph; all p < 0.05). Two years post-operation, the A/B ratio rose in the reamer group (0.96 ± 0.05→1.00 ± 0.05 on the AP radiograph and 0.94 ± 0.03→1.00 ± 0.0.04 on the lateral radiograph; all p < 0.05), while it decreased in the CDS group (0.99 ± 0.02→0.96 ± 0.05 on the AP radiograph and 0.97 ± 0.03→0.93 ± 0.06 on the lateral radiograph; all p < 0.05). Conclusion: The use of CDS for femoral tunnel creation in primary ACL reconstruction provides a potential advantage by limiting tunnel widening compared to the conventional rigid-reamer approach.

Tunnel widening after ACL reconstruction with different fixation techniques: aperture fixation with biodegradable interference screws versus all-inside technique with suspensory cortical buttons. 5-year data from a prospective randomized trial.

BACKGROUND: The aim of the present study was to examine tunnel widening and clinical outcomes after anterior cruciate ligament reconstruction (ACLR) using two different fixation methods: aperture fixation with biodegradable interference screws versus all-inside ACLR with suspensory cortical buttons. METHODS: Tunnel widening was assessed using volumetric and diameter measurements on magnetic resonance imaging (MRI) scans directly after surgery, as well as 6 months and 2 and 5 years postoperatively. Clinical outcomes were assessed after 5 years with instrumented tibial anteroposterior translation measurement (KT-1000), single-leg hop testing, and the IKDC, Lysholm, and Tegner activity scores. RESULTS: At the final follow-up, the study population consisted of 21 patients, 12 of whom underwent screw fixation and 9 of whom had button fixation. 3 patients with all-inside ACLR had sustained early repeat ruptures within 6 months after surgery and had to be excluded from the further analysis. With screw fixation, the tibial tunnel volume changed significantly more over time compared to all-inside button fixation, with a larger initial increase at 6 months (from postoperative 2.9 ± 0.2 to 3.3 ± 0.2 cm3 at 6 months versus 1.7 ± 0.1 to 1.9 ± 0.2 cm3) and a greater final decrease over 2-5 years postoperatively (from 3.1 ± 0.2 to 1.9 ± 0.2 cm3 versus 1.8 ± 0.2 ± 0.1 to 1.3 ± 0.1 cm3) (P < 0.001). The femoral tunnel volume remained comparable between the two groups throughout the follow-up period, with an initial 1.6 ± 0.1 cm3 in both groups and 1.2 ± 0.1 vs. 1.3 ± 0.1 after 5 years in the screw and button groups, respectively (P ≥ 0.314). The maximum tibial and femoral tunnel diameters were significantly larger with screw fixation at all four time points. Tibial diameters measured 11.1 ± 0.2, 12.3 ± 0.3, 12.3 ± 0.4, and 11.2 ± 0.4 mm in the screw group versus 8.1 ± 0.3, 8.9 ± 0.3, 9.1 ± 0.4 and 8.2 ± 0.5 mm in the button group (P < 0.001). Femoral diameters measured 8.6 ± 0.2, 10.5 ± 0.4, 10.2 ± 0.3, and 8.9 ± 0.3 versus 7.3 ± 0.3, 8.4 ± 0.4, 8.4 ± 0.3, 7.5 ± 0.3, respectively (P ≤ 0.007). Four patients (33%) in the screw group exceeded a diameter of 12 mm on the tibial side after 5 years versus none in the button group (not significant, P = 0.104). Tibial anteroposterior translation measurement with KT-1000 after 5 years was 2.3 ± 2.4 mm in the screw group versus 3.2 ± 3.5 mm in the button group (not significant, P = 0.602). There were no significant differences between the groups in any of the other clinical outcomes. CONCLUSION: Tibial tunnels in ACLR with screw fixation were associated with a larger increase in tunnel volume within the first 2 years and a greater decrease up to 5 years after surgery, while femoral tunnel volumes did not differ significantly. On the tibial side, the need for staged revision ACLR may be greater after biodegradable interference screw fixation if repeat ruptures occur, especially within the first 2 years after primary ACLR. Concerns may remain regarding a higher graft failure rate with all-inside ACLR. LEVEL OF EVIDENCE: II. RCT CONSORT: NCT01755819.

Osteoconductive Scaffold Placed at the Femoral Tunnel Aperture in Hamstring Tendon ACL Reconstruction: A Randomized Controlled Trial.

Background: Bone tunnel enlargement after single-bundle anterior cruciate ligament reconstruction remains an unsolved problem that complicates revision surgery. Hypothesis: Positioning of an osteoconductive scaffold at the femoral tunnel aperture improves graft-to-bone incorporation and thereby decreases bone tunnel widening. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: In a 1:1 ratio, 56 patients undergoing primary anterior cruciate ligament reconstruction were randomized to receive femoral fixation with cortical suspension fixation and secondary press-fit fixation at the tunnel aperture of the tendon graft only (control) or with augmentation by an osteoconductive scaffold (intervention). Adverse events, patient-reported outcomes, and passive knee stability were recorded over 2 years after the index surgery. Three-dimensional bone tunnel widening was assessed using computed tomography at the time of surgery and 4.5 months and 1 year postoperatively. Results: The intervention group exhibited a similar number of adverse events as the control group (8 vs 10; P = .775) including 2 partial reruptures in both groups. The approach was feasible, although 1 case was encountered where the osteoconductive scaffold was malpositioned without adversely affecting the patient's recovery. There was no difference between the intervention and control groups in femoral bone tunnel enlargement, as expressed by the relative change in tunnel volume from surgery to 4.5 months (mean ± SD, 36% ± 25% vs 40% ± 25%; P = .644) and 1 year (19% ± 20% vs 17% ± 25%; P =.698). Conclusion: Press-fit graft fixation with an osteoconductive scaffold positioned at the femoral tunnel aperture is safe but does not decrease femoral bone tunnel enlargement at postoperative 1 year. Registration: NCT03462823 (ClinicalTrials.gov identifier).

Does medial patellofemoral ligament reconstruction result in femoral tunnel enlargement? A systematic review.

BACKGROUND: Medial patellofemoral ligament (MPFL) reconstruction is a common surgical procedure for treating patellar instability. The primary aim of this systematic review was to determine whether MPFL reconstruction (MPFLR) leads to femoral tunnel enlargement (FTE). The secondary aims were to explore the clinical effects and risk factors of FTE. Electronic databases (MEDLINE, Global Health, Embase), currently registered studies, conference proceedings and the reference lists of included studies were searched independently by three reviewers. There were no constraints based on language or publication status. Study quality assessment was conducted. 3824 records were screened in the initial search. Seven studies satisfied the inclusion criteria, evaluating 380 knees in 365 patients. Rates of FTE following MPFLR ranged from 38.7 to 77.1%. Five low quality studies reported FTE did not lead to detrimental clinical outcomes as assessed with the Tegner, Kujala, IKDC, and Lysholm scores. There is conflicting evidence regarding change in femoral tunnel width over time. Three studies (of which two had a high risk of bias) reported age, BMI, presence of trochlear dysplasia and tibial tubercle-tibial groove distance did not differ between patients with and without FTE, suggesting these are not risk factors for FTE. CONCLUSION: FTE is a common postoperative event following MPFLR. It does not predispose poor clinical outcomes. Current evidence lacks the ability to identify its risk factors. The reliability of any conclusions drawn is hindered by the low level of evidence of the studies included in this review. Larger prospective studies with long-term follow up are required to reliably ascertain the clinical effects of FTE.

Combined press-fit and extracortical fixation in patellar tendon anterior cruciate ligament reconstruction results in reliable graft fixation and early bone block incorporation.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction with bone-patellar-tendon-bone (BPTB) autograft has the potential biological advantage of direct bone-to-bone healing over soft tissue grafts. The primary aim of this study was to investigate possible graft slippage and therefore fixation strength in a modified BPTB autograft technique with suspensory fixation on both sides for primary ACL reconstruction until bony integration takes place. METHODS: Twenty-one patients undergoing primary ACL reconstruction with a modified BPTB autograft (bone-on-bone (BOB) technique) between August 2017 and August 2019 were included in this prospective study. A computed tomography (CT) scan of the affected knee was performed directly postoperatively, as well as 3 months postoperatively. Examiner-blinded parameters for graft slippage, early tunnel widening, bony incorporation, as well as remodeling of the autologous refilled patellar harvest site were investigated. RESULTS: A series of 21 patients treated with a BPTB autograft with this technique underwent two CT investigations. Comparison of CT scans showed no bone block displacement and therefore no graft slippage in the patient cohort. Only one patient showed signs of early tunnel enlargement. Radiological bone block incorporation took place showing bony bridging of the graft to the tunnel wall in 90% of all patients. Furthermore, 90% showed less than 1 mm bone resorption of the refilled harvest site at the patella. CONCLUSIONS: Our findings suggest graft fixation stability and reliability of anatomic BPTB ACL reconstruction with a combined press-fit and suspensory fixation technique by absence of graft slippage within the first 3 months postoperatively.

Human Trials on the Prevention of Tunnel Widening by the Emdogain in Anterior Cruciate Ligament Reconstruction.

Background Although anterior cruciate ligament reconstruction (ACLR) is an established procedure, some problems remain, such as bone tunnel widening after ACLR. In animal studies, Emdogain (EMD) prevented tunnel widening by promoting tendon-bone healing. This study aimed to evaluate the effects of EMD on the prevention of tunnel widening after anterior cruciate ligament (ACL) injury in humans. Methods Nineteen patients who underwent ACLR were included. Seven patients in the EMD group were administered EMDs into the femoral tunnel during ACLR, while 12 patients in the control group were not administered EMDs. After surgery, at two and four weeks and three, six, and 12 months, femoral and tibial tunnel widening were evaluated on computed tomography images. Anteroposterior laxity and clinical scores such as the Lysholm score, the International Knee Documentation Committee (IKDC) subjective form, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were assessed before surgery and 12 months postoperatively. Results Tunnel widening on the femoral side was significantly smaller in the EMD group than in the control group at two weeks. However, there was no significant difference between the two groups at 12 months. There were no significant differences in anteroposterior laxity and clinical scores between the groups before and 12 months after surgery. Conclusion EMD administration into the bone tunnel did not prevent tunnel widening at 12 months after ACLR, although tunnel widening of the femoral tunnel was reduced by EMD administration in the early phase.

Low Femoral Tunnel Widening Incidence Rate After ACL Reconstruction Using Patellar Tendon Graft with Press-Fit Fixation.

Background: Femoral tunnel widening after ACL reconstruction is a common phenomenon. We hypothesized that using a patellar tendon graft with a press-fit fixation technique without any fixation device reduces the incidence of femoral tunnel widening. Methods: This study was conducted on 467 patients with ACL surgery between 2003 and 2015. Two hundred and nineteen of them had an ACL surgery with patellar tendon (PT) graft, and two hundred and forty-eight of them with hamstring tendon (HS). Exclusion criteria were history of previous ACL reconstruction of either knee, multiple ligament injury, or evidence of osteoarthritis on radiographs. The femoral tunnels were measured on the anteroposterior (ap) and lateral radiographs 6 months after the operation. Two independent orthopedic surgeons measured all radiographs twice and recorded the tunnel widenings. We hypothesized that using an implant-free press-fit technique with PT graft can reduce the femoral tunnel widening incidence rate. Results: The mean incidence rate of the tunnel widening in the HS group was, on the AP and the lateral femoral views, 88% (n = 217) and 83% (n = 205), while in the PT group, 17% (n = 37) and 2% (n = 4), respectively. There was a significant difference both on AP and lateral radiographs (HS vs. PT: fem. AP: 89% vs. 17% p < 0.001; HS vs. PT: fem. lat: 84% vs. 2% p < 0.001). Conclusion: The femoral tunnel widening incidence rate during an ACL reconstruction is significantly less when using PT tendon with femoral press-fit fixation than when using HT tendon with suspensory fixation method.

Femoral Tunnel Position Affects Postoperative Femoral Tunnel Widening after Anterior Cruciate Ligament Reconstruction with Tibialis Anterior Allograft.

This study aims to identify potential factors for both femoral and tibial tunnel widening (TW) and to investigate the effect of TW on postoperative outcomes after anterior cruciate ligament (ACL) reconstruction with a tibialis anterior allograft. A total 75 patients (75 knees) who underwent ACL reconstruction with tibialis anterior allografts were investigated between February 2015 and October 2017. TW was calculated as the difference in tunnel widths between the immediate and 2-year postoperative measurements. The risk factors for TW, including demographic data, concomitant meniscal injury, hip-knee-ankle angle, tibial slope, femoral and tibial tunnel position (quadrant method), and length of both tunnels, were investigated. The patients were divided twice into two groups depending on whether the femoral or tibial TW was over or less than 3 mm. Pre- and 2-year follow-up outcomes, including the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, and side-to-side difference (STSD) of anterior translation on stress radiographs, were compared between TW ≥ 3 mm and TW < 3 mm. The femoral tunnel position depth (shallow femoral tunnel position) was significantly correlated with femoral TW (adjusted R2 = 0.134). The femoral TW ≥ 3 mm group showed greater STSD of anterior translation than the femoral TW < 3 mm group. The shallow position of the femoral tunnel was correlated with the femoral TW after ACL reconstruction using a tibialis anterior allograft. A femoral TW ≥ 3 mm showed inferior postoperative knee anterior stability.

No correlation exists between coracoid tunnel widening and loss of reduction after arthroscopic acromioclavicular fixation using tightrope system.

PURPOSE: To detect the widening of the tunnel of the coracoid process after arthroscopic fixation of acute acromioclavicular joint (ACJ) dislocation using the TightRope system and its correlation with loss of reduction and functional scores. METHODS: From 2016 to 2018, a prospective study was performed on twenty-three patients with acute grade III-V ACJ dislocation. Arthroscopic TightRope repair of the ACJ was performed. Coracoid tunnel widening was measured by CT, and the coracoclavicular distance was measured on the radiographs immediately postoperatively and at 12 months. The Constant Shoulder Score, Oxford Shoulder Score, Nottingham Clavicle Score and Visual analog scale were used as outcome measures at 12 months. RESULTS: The coracoid tunnel diameter to horizontal coracoid diameter ratio increased from 22.8 ± 3.7% immediately postoperatively to 38.5 ± 5.5% at 12 months (p < 0.001). The coracoclavicular (CC) distance showed an increase from a mean of 10.8 ± 1.7 mm to a mean of 11.8 ± 2.5 at 12 months (p < 0.001). There was no correlation between the increase in the coracoclavicular distance and the patients' functional clinical scores or coracoid tunnel widening. CONCLUSION: Coracoid tunnel widening and radiological loss of reduction occur after arthroscopic fixation of acute ACJ dislocation with the TightRope system. However, they do not correlate with each other or with the functional scores of the patient. LEVEL OF EVIDENCE: Level IV.

Implant-dependent behavior of tunnel widening and clavicular button migration after arthroscopic-assisted treatment of acromioclavicular joint instabilities.

INTRODUCTION: Despite ongoing discussions for the previous few decades, there is still no consensus regarding the optimal surgical technique for acromioclavicular joint instabilities. The purpose of this study was to determine the impact of various implant materials following arthroscopically assisted stabilization of acromioclavicular joint instabilities on tunnel widening and implant migration. We hypothesized an implant-dependent behavior for tunnel widening and implant migration with differences when comparing acute and chronic acromioclavicular joint instabilities. METHODS: This study compared 105 patients with acromioclavicular joint instabilities that were managed operatively with coracoclavicular double button constructs. Two of the groups containing acute cases were treated with either a double button construct with a wire (TR) or a tape (D) as a central pillar. The two groups with chronic cases were either treated with a wire (T+) or tape D+ as a central pillar and additional hamstring tendon augmentation (+). One central transclavicular-transcoracoidal drill channel was made in the acute cases, while additional medial and lateral drill channels to augment the central pillar with the hamstring tendon were made. The central drill channel in all cases and the medial/lateral drill channels in chronic cases were subsequently radiologically analyzed immediately postoperatively and at follow-up. Following this, additional radiological analysis of the implant migration of the clavicular button took place. RESULTS: All groups showed significant tunnel widening of the central drill channel at follow-up (p ≤ 0.001). The TR+ technique demonstrated significant widening in both the medial (p ≤ 0.001) and lateral (p ≤ 0.001) drill channels. The D and D+ group displayed significant higher rates of clavicular button migration to a cortical and intraosseous level (p ≤ 0.002). CONCLUSION: Tunnel widening and implant migration following arthroscopically assisted management of acromioclavicular joint instabilities are dependent on the chosen implant. The stable tape showed a significantly increased degree of tunnel widening with respect to the central drill channel in comparison with the wire. In contrast, a higher degree of load capacity of the tape ultimately favors a protected intraosseous graft healing for chronic cases, which leads to less tunnel widening of the medial and lateral drill channel. Finally, the D/D+ implant groups showed higher rates of implant migration due to lower contact surface area of the implant at the upper clavicular cortex.

Acromioclavicular joint suture button repair leads to coracoclavicular tunnel widening.

PURPOSE: Biomechanical evaluation of three different suture button devices used in acromioclavicular joint repair and analysis of their effect on post-testing tunnel widening. METHODS: Eighteen human shoulder girdles were assigned into three groups with a similar mean bone mineral density. Three different single-tunnel acromioclavicular repair devices were tested: (1) AC TightRope® with FiberWire; (2) AC Dog Bone™ Button with FiberTape; (3) Low Profile AC Repair System. Biomechanical testing was performed simulating the complex movement of the distal clavicle as follows. A vertical load of 80 N was applied continuously. The rotation of the clavicle about its long axis was set at 10° anterior and 30° posterior for 2500 cycles at 0.25 Hz. The horizontal translation of the clavicle was set at 6 mm medial and 6 mm lateral for 10,000 cycles at 1 Hz. The coracoclavicular distance was measured before and after testing. After testing, each sample underwent micro-CT analysis. Following 3D reconstruction, the area of the bone tunnels was measured at five defined cross sections. RESULTS: In TightRope® and Dog Bone™ groups, all samples completed testing, whereas in the Low Profile group, three out of six samples showed system failure. The mean absolute difference of coracoclavicular distance after testing was significantly greater in the Low Profile group compared to TightRope® and Dog Bone™ groups (4.3 ± 1.3 mm vs 1.9 ± 0.7 mm vs 1.9 ± 0.8 mm; p = 0.001). Micro-CT analysis of the specimens demonstrated significant tunnel widening in the inferior clavicular and superior coracoid regions in all three groups (p < 0.05). CONCLUSION: Significant tunnel widening can be observed for all devices and is primarily found in the inferior parts of the clavicle and superior parts of the coracoid. The Low Profile AC Repair System showed inferior biomechanical properties compared to the AC TightRope® and AC Dog Bone™ devices. Therefore, clinicians should carefully select the type of acromioclavicular repair device used and need to consider tunnel widening as a complication.

Tibial tunnel expansion does not correlate with four-strand graft maturation after ACL reconstruction using adjustable cortical suspensory fixation.

PURPOSE: Anterior cruciate ligament reconstruction (ACLR) using a short, quadrupled semitendinosus (ST-4) autograft, fixed  with an adjustable suspensory fixation (ASF), has several potential advantages. However, the construct is suspected to generate micromotion, tunnel widening and poor graft maturation. The aim of this study was to evaluate post-operative tibial tunnel expansion, graft maturation and clinical outcomes for this type of ACLR. METHODS: One-hundred and forty-nine patients were reviewed at a minimum of 2 years following 4-ST ACLR, mean 25.6 ± 3.5 months [24-55], with clinical follow-up and MRI scans. Graft maturity of the intra-articular part of the graft and the tibial tunnel portion was assessed using Signal-to-Noise Quotient (SNQ) and Howell score. Tibial tunnel expansion, bone-graft contact and graft volume in the tibial tunnel were calculated from the MRI scans. RESULTS: Mean tibial tunnel expansion was 13 ± 16.5% [12-122]. Mean SNQ for graft within the tibial tunnel was 3.8 ± 7.1 [ - 7.7 to 39] and 2.0 ± 3.5 [ - 14 to 17] for the intra-articular portion of the graft. The Howell score for graft within the tibial tunnel was 41% Grade I, 37% Grade 2, 20% Grade 3, 2% grade 4, and for the intra-articular part 61% Grade 1, 26% Grade 2, 13% Grade 3 and 1% Grade 4. The mean tibial tunnel bone-graft contact was 81 ± 23% [0-100] and mean graft volume was 80 ± 22% [0-100]. No correlation was found between tibial tunnel expansion and graft maturity assessed at both locations. Graft maturity was correlated with higher graft-bone contact and graft volume in the tibial tunnel (p < 0.05). CONCLUSIONS: ST-4 ACLR with ASF had low levels of tunnel enlargement at 2 years. No correlation was found between graft maturation and tibial tunnel expansion. Graft maturity was correlated with graft-bone contact and graft volume in the tibial tunnel. LEVEL OF EVIDENCE: Level III.

Arthroscopic Latarjet procedure and suture-button fixation: can we predict nonunion early?

BACKGROUND: The arthroscopic Latarjet procedure is a technically challenging technique that provides well-known results. The first series reported fixation with screws. An alternative fixation technique has been proposed, using a button, to improve the reproducibility and to decrease the complications due to screws. The first reports using this fixation technique have yielded comparable rates of fusion. The objective of this study was to assess the fusion rate and bone modifications with this type of fixation. METHODS: Two hundred sixteen patients were included in this prospective study. An arthroscopic Latarjet procedure, fixed with 1 button according to the Smith & Nephew technique, was performed by a single surgeon for the treatment of anterior instability. The radiographic protocol consisted of computed tomography scans at 3, 12, and 24 weeks postoperatively. We measured the coronal and sagittal positions of the bone block, distance between the bone block and the glenoid, diameter of the glenoid tunnel, fusion rate, and time to fusion. RESULTS: The position was deemed flush in 92.6% of cases in the coronal plane and under the equator in 87.5% of cases in the sagittal plane. At last follow-up, we observed 9 cases of nonunion (4%), as well as 18 cases of delayed fusion. The fusion rate was 92% at 3 months and 96% at 6 months. For bone blocks that ultimately healed, the diameter of the glenoid tunnel was <2 mm in 62% of cases at 3 weeks and <1 mm in 90% of cases at 3 months. Conversely, the diameter of this tunnel significantly increased and was >3 mm in all cases of delayed union or nonunion. CONCLUSION: The described technique achieved a reliable position of the bone block and a very good fusion rate with a new type of fixation. The time to obtain fusion can be lengthy, occurring between the third and sixth months. The diameter of the glenoid tunnel was the best predictive factor for fusion. Widening of the glenoid tunnel diameter >3 mm during the first 3 weeks was the most predictive factor for delayed union or nonunion of the bone block. This finding is probably explained by a sliding effect of the sutures through this tunnel, comparable to the bungee effect in anterior cruciate ligament repair in the knee.

Eccentrically widened bone tunnels after all-inside anterior cruciate ligament reconstruction: a computed tomography and three-dimensional model-based analysis.

PURPOSE: To evaluate the extent of tunnel widening after anterior cruciate ligament reconstruction (ACLR) using the all-inside technique and to establish its correlation with patient-reported clinical outcomes and femoral graft bending angle (GBA). METHODS: Tunnel widening was evaluated using computed tomography (CT)-based three-dimensional (3D) models, and the femoral GBA was directly measured on CT images using the Picture Archiving and Communication System (PACS) software. Clinical follow-up was routine procedure, and patient-reported clinical outcomes mainly included International Knee Documentation Committee (IKDC), Lysholm, and Knee Injury and Osteoarthritis Outcome Scores (KOOS) scores, and subjective knee stability assessment. RESULTS: Fifty-two patients received standard all-inside ACLR, with a median follow-up of 6 months. Reconstructed anterior cruciate ligaments (ACLs) were scanned during the first 3 days and 6 months after surgery. On both the femoral and tibial sides, bone tunnels were most significantly enlarged at the articular aperture segment; the femoral tunnel was 9.2 ± 1.3 mm postoperatively and was significantly enlarged by 32% to a mean tunnel diameter of 12.1 ± 2.0 mm at 6 months after surgery. Moreover, the extent of tunnel enlargement gradually decreased as the measured levels approached those of the bone cortex. The femoral tunnel center was shifted into the anterior and distal direction, and the tibial tunnel center was shifted into the posterior and lateral direction. Additionally, the mean femoral GBA was 105.9° ± 8.1° at the 6-month follow-up. Tunnel enlargement and GBA were not significantly correlated with patient-reported outcomes. CONCLUSIONS: Femoral and tibial tunnels were significantly greater and eccentrically shifted at the 6-month follow-up after all-side ACLR. However, the extent of tunnel widening does not markedly affect the short-term clinical outcomes. Meanwhile, the femoral GBA was not significantly correlated with femoral tunnel widening or patient-reported outcomes. Although the tunnel widening following all-inside ACLR was not associated with clinical outcomes, it potentially caused difficulties in revision ACLR. LEVEL OF EVIDENCE: Level IV.

Comparison of two different types of hybrid Tibial fixations for anterior cruciate ligament reconstruction: a prospective comparative cohort study.

BACKGROUND: Previous studies have compared different kinds of fixations for anterior cruciate ligament reconstruction. Nevertheless, there is no optimal method to date. To the best of authors' knowledge, there is no article discussing the combination of adjustable suspensory device and interference screw for hybrid tibial fixation. METHODS: In total, 66 patients (n = 34, adjustable suspensory device and interference screw; n = 32, cortical screw and interference screw) were analyzed. Their International Knee Documentation Committee score and Tegner activity level scale were evaluated before and after a 2-year follow-up. The Single Assessment Numeric Evaluation score was evaluated after a 2-year follow-up. Physical exams such as range of motion, anterior knee pain (VAS > = 3) and Lachman test were assessed before and at least 12 months after surgery. To evaluate tunnel widening, anteroposterior and lateral view radiography was conducted 1 day and at least 12 months after surgery. A more than 10% change was considered tibial tunnel widening. Mann-Whitney U test, independent t test, paired t test, Fisher's exact test and chi-squared test were used to compare the variables. Linear and logistic regression models were applied to adjust for potential confounders. RESULTS: No variable except gender (P = 0.006) showed significant difference with regard to demographic data. After adjustment, there was no statistically significant difference between the groups regarding post-operative physical exams. Patients who used adjustable suspensory device and interference screw had lower post-operative Single Assessment Numeric Evaluation score (adjusted ß - 8.194; P = 0.017), Tegner activity level scale (adjusted ß - 1.295; P = 0.001) and pre-operative degrees of knee flexion (adjusted ß - 2.825; P = 0.026). Less percentage of tunnel widening in the lateral view of radiographs was seen in patients in group of adjustable suspensory device and interference screw (adjusted ß - 1.733; P = 0.038). No significant difference was observed in the anteroposterior view of radiographs (adjusted ß - 0.667; P = 0.26). CONCLUSION: In these 66 patients, we observed less tibial tunnel widening and lower post-operative functional scores in the group of adjustable suspensory device and interference screw. Both groups displayed similar outcomes of physical exams as well as improvement after operation. The proposed method may become an alternative option. Nonetheless, the quality of our study is still limited, and thus further studies are warranted to determine the efficacy and further application. TRIAL REGISTRATION: Joint Institutional Review Board of Taipei Medical University, Taipei, Taiwan (No: N201805094 ). STUDY DESIGN: Prospective comparative cohort study; Level of evidence, II.