Biological Versus Nonbiological Reconstruction of the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint: A Retrospective Study.

PURPOSE: The purpose of this study was to compare clinical and radiologic outcomes of biological ligament reconstruction (BLR) versus nonbiological ligament reconstruction (NBLR) for chronic injuries involving the ulnar collateral ligament of the thumb's metacarpophalangeal joint. METHODS: Forty-two patients who underwent static BLR (n = 24) or NBLR (n = 18) were included in this retrospective analysis. Preoperative, postoperative, and contralateral thumb measurements (clinical evaluation, radiographs, and subjective outcome questionnaires) were compared over a mean of 38 months of follow-up. RESULTS: Average postoperative thumb metacarpophalangeal and interphalangeal joint ranges of motion were 2° to 54° and 0 to 71°, respectively, for BLR and 0° to 58° and 0° to 71°, respectively, for NBLR. Average grip and pinch strengths, relative to the unaffected hand, were 102% and 84% versus 103% and 89%, respectively. All patients demonstrated stability with a firm end point, compared with the unaffected thumb. The average Quick Disabilities of the Arm, Shoulder, and Hand score among all patients was 12 for the disability/symptom module, 0 for the sports module, and 17 for the work module. Stiffness was reported among four patients, and no patient sustained wound-related issues or other complications. CONCLUSIONS: Nonbiological ligament reconstruction of the thumb ulnar collateral ligament generates short-term outcomes comparable with those of BLR, potentially allowing for expedited recovery and rehabilitation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Isometry of anteromedial reconstructions mimicking the deep medial collateral ligament depends on the femoral insertion.

PURPOSE: This study aimed to investigate the length change patterns of the native deep medial collateral ligament (dMCL) and potential anteromedial reconstructions (AMs) that might be added to a reconstruction of the superficial MCL (sMCL) to better understand the control of anteromedial rotatory instability (AMRI). METHODS: Insertion points of the dMCL and potential AM reconstructions were marked with pins (tibial) and eyelets (femoral) in 11 cadaveric knee specimens. Length changes between the pins and eyelets were then tested using threads in a validated kinematics rig with muscle loading of the quadriceps and iliotibial tract. Between 0° and 100° knee flexion, length change pattern of the anterior, middle and posterior part of the dMCL and simulated AM reconstructions were analysed using a rotary encoder. Isometry was tested using the total strain range (TSR). RESULTS: The tibiofemoral distance of the anterior dMCL part lengthened with flexion (+12.7% at 100°), whereas the posterior part slackened with flexion (-12.9% at 100°). The middle part behaved almost isometrically (maximum length: +2.8% at 100°). Depending on the femoral position within the sMCL footprint, AM reconstructions resulted in an increase in length as the knee flexed when a more centred position was used, irrespective of the tibial attachment position. Femoral positioning in the posterior aspect of the sMCL footprint exhibited <4% length change and was slightly less tight in flexion (min TSR = 3.6 ± 1.5%), irrespective of the tibial attachment position. CONCLUSION: The length change behaviour of potential AM reconstructions in a functionally intact knee is mainly influenced by the position of the femoral attachment, with different tibial attachments having a minimal effect on length change. Surgeons performing AM reconstructions to control AMRI would be advised to choose a femoral graft position in the posterior part of the native sMCL attachment to optimise graft length change behaviour. Given the high frequency of MCL injuries, sufficient restoration of AMRI is essential in isolated and combined ligamentous knee injuries. LEVEL OF EVIDENCE: There is no level of evidence as this study was an experimental laboratory study.

Valgus malalignment causes increased forces on a medial collateral ligament reconstruction under dynamic valgus loading: A biomechanical study.

PURPOSE: To investigate the forces on a medial collateral ligament (MCL) reconstruction (MCLR) relative to the valgus alignment of the knee. METHODS: Eight fresh-frozen human cadaveric knees were subjected to dynamic valgus loading at 400 N using a custom-made kinematics rig. After resection of the superficial medial collateral ligament, a single-bundle MCLR with a hamstring tendon autograft was performed. A medial opening wedge distal femoral osteotomy was performed and fixed with an external fixator to gradually adjust the alignment in 5° increments from 0° to 10° valgus. For each degree of valgus deformity, the resulting forces acting on the MCLR were measured through a force sensor and captured in 15° increments from 0° to 60° of knee flexion. RESULTS: Irrespective of the degree of knee flexion, increasing valgus malalignment resulted in significantly increased forces acting on the MCLR compared to neutral alignment (p < 0.05). Dynamic loading at 5° valgus resulted in increased forces on the MCLR at all flexion angles ranging between 16.2 N and 18.5 N (p < 0.05 from 0° to 30°; p < 0.01 from 45° to 60°). A 10° valgus malalignment further increased the forces on the MCLR at all flexion angles ranging between 29.4 N and 40.0 N (p < 0.01 from 0° to 45°, p < 0.05 at 60°). CONCLUSION: Valgus malalignment of the knee caused increased forces acting on the reconstructed MCL. In cases of chronic medial instabilities accompanied by a valgus deformity ≥ 5°, a realigning osteotomy should be considered concomitantly to the MCLR to protect the graft and potentially reduce graft failures. LEVEL OF EVIDENCE: Level III.

The Utility of Stress Ultrasound in Identifying Risk Factors for Elbow Ulnar Collateral Ligament Tear: A Longitudinal Study of 203 Professional Baseball Players.

BACKGROUND: Injuries to the medial ulnar collateral ligament (UCL) are common among baseball pitchers due to repetitive stress on the soft tissue stabilizers of the elbow during pitching. Dynamic stress ultrasound (SUS) can be used to evaluate the UCL and ulnohumeral joint to identify anatomic risk factors of those who will require UCL reconstruction (UCLR). PURPOSE: To determine whether any adaptive or morphological changes detectable on SUS can predict injury to the UCL in professional baseball pitchers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 203 professional baseball pitchers who underwent SUS at preseason training sessions over the course of 18 years were categorized into 1 of 2 groups: those without a history of shoulder, arm, elbow, or forearm surgery or injuries (healthy cohort; n = 184) and those who underwent UCLR the same season as SUS (UCLR cohort; n = 19). Ligament thickness, joint spacing, and laxity were compared. An additional matched cohort analysis was conducted using 10 players from each group to detect differences in the progression of UCL and ulnohumeral joint measures in the year before injury. RESULTS: The UCLR cohort, when compared with the healthy cohort, had higher relative (ie, nondominant-side measurements subtracted from dominant-side measurements) resting ulnohumeral joint space (median, 0.50 vs 0.20 mm, respectively; P = .006) and higher rates of hypoechoic foci (57.9% vs 30.4%, respectively; P = .030). Players of both groups had similar dominant UCL thickness (P = .161), ulnohumeral joint space at rest (P = .321), space under stress (P = .498), and laxity (P = .796). Groups did not differ in terms of relative UCL thickness, ulnohumeral joint space under stress, or relative laxity. In the year before UCL injury, the UCLR cohort, compared with the matched healthy cohort, had a greater increase in mean dominant UCL thickness (0.94 vs -0.60 mm, respectively; P = .038) and a greater increase in relative median UCL thickness (1.35 vs -0.35 mm, respectively; P = .045). Players in the healthy cohort were statistically older than those in the UCLR cohort (23 vs 22 years, respectively; P = .004). No differences in ulnohumeral stress spacing or laxity were detected. CONCLUSION: SUS of players who underwent UCLR demonstrated a progressive increase in UCL thickness over 1 year, higher rates of hypoechoic foci, and increased ulnohumeral rest space compared with SUS of uninjured players.

[Injuries of the ankle ligaments]. / Bandverletzungen des oberen Sprunggelenks.

Lateral ligament injuries are the most common injuries of the ankle joint and are usually treated with early weight bearing after a short period of immobilization. If the clinical presentation is suspicious, additional injuries to the deltoid ligament complex and the syndesmosis should be considered. The indications for additional diagnostics should be generously applied. Injuries to the deltoid ligament usually occur as part of a complex ankle injury and should also be addressed in the surgical treatment of accompanying injuries. Chronic instability in this area necessitates complex bony and soft tissue procedures. Syndesmotic injuries with insufficiency of the capsule-ligament apparatus are frequent in ankle fractures and are stabilized during fracture treatment. Isolated syndesmotic instability should also be surgically treated as chronic injuries are usually associated with poor clinical results and early osteoarthritis.

Single-Strand "Short Isometric Construct" Medial Collateral Ligament Reconstruction Restores Valgus and Rotational Stability While Isolated Deep MCL and Superficial MCL Reconstruction Do Not.

BACKGROUND: Historical MCL (medial collateral ligament) reconstruction (MCLR) techniques have focused on the superficial MCL (sMCL) to restore valgus stability while frequently ignoring the importance of the deep MCL (dMCL) in controlling tibial external rotation. The recent recognition of the medial ligament complex importance has multiple studies revisiting medial anatomy and questioning contemporary MCLR techniques. PURPOSE: To assess whether (1) an isolated sMCL reconstruction (sMCLR), (2) an isolated dMCL reconstruction (dMCLR), or (3) a novel single-strand short isometric construct (SIC) would restore translational and rotational stability to a knee with a dMCL and sMCL injury. STUDY DESIGN: Controlled laboratory study. METHODS: Biomechanical testing was performed on 14 fresh-frozen cadaveric knee specimens using a custom multiaxial knee activity simulator. The specimens were divided into 2 groups. The first group was tested in 4 states: intact, after sectioning the sMCL and dMCL, isolated sMCLR, and isolated dMCLR. The second group was tested in 3 states: intact, after sectioning the sMCL and dMCL, and after single-strand SIC reconstruction (SICR). In each state, 4 loading conditions were applied at 0°, 20°, 40°, 60°, and 90° of knee flexion: 8-N·m valgus torque, 5-N·m external rotation torque, 90-N anterior drawer, and combined 90-N anterior drawer plus 5-N·m tibial external rotation torque. Anterior translation, valgus rotation, and external rotation of the knee were measured for each state and loading condition using an optical motion capture system. RESULTS: sMCL and dMCL transection resulted in increased laxity for all loading conditions at all flexion angles. Isolated dMCLR restored external rotation stability to intact levels throughout all degrees of flexion, yet valgus stability was restored only at 0° of flexion. Isolated sMCLR restored valgus and external rotation stability at 0°, 20°, and 40° of flexion but not at 60° or 90° of flexion. Single-strand SICR restored valgus and external rotation stability at all flexion angles. In the combined anterior drawer plus external rotation test, isolated dMCL and single-strand SICR restored stability to the intact level at all flexion angles, while the isolated sMCL restored stability at 20° and 40° of flexion but not at 60° or 90° of flexion. CONCLUSION: In the cadaveric model, single-strand SICR restored valgus and rotational stability throughout the range of motion. dMCLR restored rotational stability to the knee throughout the range of motion but did not restore valgus stability. Isolated sMCLR restored external rotation and valgus stability in early flexion. CLINICAL RELEVANCE: In patients with anteromedial rotatory instability in the knee, neither an sMCLR nor a dMCLR is sufficient to restore stability.

Dynamic Stress Ultrasound Assessment of Professional Baseball Players' Elbows After Ulnar Collateral Ligament Reconstruction.

BACKGROUND: There is a paucity of data analyzing dynamic stress ultrasound (SUS) findings in elite pitchers who have undergone ulnar collateral ligament (UCL) reconstruction (UCLR) and returned to sport. PURPOSE: To identify longitudinal, perioperative changes in the elbows of professional baseball pitchers who have undergone UCLR and to compare these findings with a matched cohort of healthy pitchers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study used prospectively collected data from dynamic elbow SUS analyses of professional baseball pitchers within a single Major League Baseball organization. Pitchers were divided into 2 cohorts: a UCLR cohort and healthy cohort. The UCLR cohort eligibility included availability of (1) SUS from preseason of injury/UCLR and (2) SUS from ≥2 years after surgery. These players were 1:1 matched to players with no history of upper extremity injury to form the healthy cohort. Ligament thickness and ulnohumeral joint space at rest and under stress were directly measured. Joint laxity was calculated by subtracting joint space at rest from joint space under stress. The term "relative" was used to describe calculated differences where nondominant measurements were subtracted from dominant-side measurements. RESULTS: Eight pitchers were included in the UCLR group and matched to 8 healthy pitchers (mean age at initial SUS examination, 19.6 years). At a minimum follow-up of 2 years, there were no significant differences between groups in terms of relative or dominant arm rest space, stress space, or laxity. Longitudinally (final measurements - baseline measurements), the mean relative ulnohumeral rest space decreased in the UCLR group and increased in the healthy group (-0.36 mm vs +0.50 mm; P = .032). The finding of increased UCL thickness in the UCLR group was expected, as UCL grafts are typically thicker than native ligaments. CONCLUSION: Ulnhohumeral joint stability was achieved after UCLR as indicated by similar rest space, stress space, and joint laxity in dominant arms compared with a matched healthy cohort. A significant decrease in relative rest space after UCLR may represent the achievement of stability in surgery patients. Alternatively, the increase in ulnohumeral rest space seen in the healthy cohort may represent adaptive changes from pitching at a professional level.

Anconeus-sparing minimally invasive approach for lateral ulnar collateral ligament reconstruction using a triceps tendon autograft is an effective and safe treatment for chronic posterolateral instability of the elbow.

BACKGROUND: Surgical treatment helps to restore stability of the elbow in patients with posterolateral rotatory instability (PLRI). The anconeus muscle is one of the most important active stabilizers against PLRI. A minimally invasive anconeus-sparing approach for lateral ulnar collateral ligament (LUCL) reconstruction using a triceps tendon autograft has been previously described. The purpose of this study was to evaluate the outcome of this intervention and identify risk factors that influenced the clinical and patient-reported outcomes. METHODS: Sixty-one patients with chronic PLRI and no previous elbow surgery who underwent surgical reconstruction of the LUCL using a triceps tendon autograft in a minimally invasive anconeus-sparing approach during 2012 and 2018 were evaluated. Outcome measures included a clinical examination and the Oxford Elbow Score (OES) and the Mayo Elbow Performance Score (MEPS) questionnaires. Subjective patient outcomes were evaluated with the visual analog scale (VAS) for pain and the Subjective Elbow Value (SEV). Integrity of the common extensor tendons and centering of the radial head were assessed preoperatively on standardized magnetic resonance images (MRIs). RESULTS: Fifty-two patients were available at final follow-up. The mean age of patients was 51 ± 12 years with a mean follow-up of 53 ± 14 months (range 20-76). Clinical examination after surgery (n = 41) showed no clinical signs of instability in 98% of the patients (P < .001) and a nonsignificant improvement in range of motion. OES, MEPS, and VAS scores averaged 40 ± 10 of 48 points, 92 ± 12 of 100 points, and 1 ± 2 points, respectively, all corresponding with good or excellent outcomes. The SEV was 88%, indicating very high satisfaction with the surgery. Only 1 patient had revision surgery due to pain, and there were no reported postoperative complications in this cohort. A radial head subluxation in the MRI correlated significantly with worse postoperative outcomes. CONCLUSIONS: The anconeus-sparing minimally invasive technique for posterolateral stabilization of the elbow using a triceps tendon autograft is an effective and safe treatment for chronic posterolateral instability of the elbow with substantial improvements in elbow function and pain relief with a very low rate of persistent clinical instability.

Editorial Commentary: Ulnar Collateral Ligament Repair With Suture Augmentation May Be Superior to Reconstruction for Proximal or Distal Tears With Good- Quality Tissue.

Ulnar collateral ligament (UCL) tears in the elbow have been rising in recent years, most specifically in baseball players. Although many of these tears occur in professional (minor and major league) baseball pitchers, there has been a dramatic rise in UCL injuries in adolescents, at a rate of 9% per year. Although some UCL tears can be treated conservatively, those that fail conservative treatment often require surgical intervention to allow players to return to sport. Although UCL reconstruction has been the gold standard in surgical treatment for many years, UCL repair with suture augmentation has grown in popularity. Initial results of UCL repair with suture augmentation have been promising, and a recent review comparing UCL repair with suture augmentation from both a biomechanical and clinical outcome perspective confirms that UCL repair may be superior to reconstruction for patients with proximal or distal tears and good quality UCL tissue for repair.

Association Between Draft Order and Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers: An 18-Year Study.

BACKGROUND: The Major League Baseball (MLB) draft is a common route for players to enter professional baseball in the United States. Players taken in earlier rounds are typically higher-performing players. When looking at pitchers specifically, higher performance at the amateur level may be associated with an increased frequency of adaptive change in the throwing elbow. PURPOSE: To determine whether pitchers taken in earlier rounds of the MLB draft have a greater frequency or extent of pathological change in the elbow, as measured by dynamic stress ultrasound. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Dynamic stress ultrasounds (SUSs) were performed over 18 years on the dominant and nondominant arms of 651 professional pitchers. The 383 drafted players were grouped according to the round in which they were drafted (rounds 1-5, 6-10, 11-20, 21+). Groups were compared with respect to "relative" ulnar collateral ligament (UCL) thickness (dominant-nondominant), relative ulnohumeral joint laxity (joint space distance under stress minus joint space at rest), and the presence of pathology (calcifications, tears, hypoechoic foci, osteophytes). In addition, a subgroup analysis was done to compare the progression of SUS findings over 3 years in players for which data were available. RESULTS: Draft round groups did not differ by age, number of previous spring training, or handedness. Comparing baseline measurements, there was no significant relationship between draft round and relative UCL thickness (P = .932), relative laxity (P = .996), or presence of pathology detectable on SUS (P = .642). However, increased relative UCL thickness was significantly associated with the presence of pathology on SUS (odds ratio, 1.45; 95% CI, 1.26-1.69; P < .001). Longitudinally, there was no significant relationship between draft round and 3-year progression of relative laxity, relative UCL thickness, or clinical progression of pathology. CONCLUSION: Higher-performing pitchers are drafted earlier in the MLB draft. This may be attributable to peak pitch velocity, in-game performance, visibility gained during player showcases, or any number of other sport-specific variables. However, despite this, there was no significant relationship between draft round and adaptive changes to the elbow or specific properties of the UCL on stress ultrasound.

Ulnar Collateral Ligament Repair With Suture Tape Augmentation: Can You Overtighten?

BACKGROUND: There has been a renewed interest and, recently, wider implementation of ulnar collateral ligament (UCL) repair in throwing athletes because of improvement in ligament repair technology and corresponding outcome data. PURPOSE: To compare the biomechanical parameters and failure mode between 2 brace-tightening techniques for UCL repair. STUDY DESIGN: Controlled laboratory study. METHODS: Eleven matched pairs of cadaveric arms were procured. One limb from each pair underwent UCL repair with suture tape augmentation with either (1) attempted restoration of physiologic ligament tension or (2) maximal tension. Each specimen was subjected to 10 cycles of subfailure valgus torque at 90º of flexion in the intact state after UCL avulsion and then after UCL repair. Specimens were then torqued to failure. Articular contact mechanics, linear gap distance, angular displacement, failure torque, failure stiffness, and suture tape pull-through length were recorded. Two-way analysis of variance and paired t tests were used to test for statistical differences. RESULTS: There was a significant effect (P = .01) of tightening on joint contact area. There was a significant decrease in gap distance (P = .03) and angular displacement (P = .004) from the torn condition to the repaired condition for the maximum tension group, without a significant difference in gap distance from the intact condition. Failure torque and stiffness were not significantly different between groups, although there was a significant difference (P = .001) in the overall suture tape pull-through length. CONCLUSION: Although there are potential physiologic changes at time zero-including significant decreases in contact area, normalized gap distance, and normalized angular displacement with maximal tension repair-examination of failure biomechanics suggests that these effects may be mitigated over time within the construct by suture tape pull-through at the tape-anchor interface. Neither method of UCL repair with suture tape augmentation resulted in overconstraint of the elbow joint compared with the native ligament biomechanics. CLINICAL RELEVANCE: As more long-term outcome data from UCL repair with suture tape augmentation emerge, there will be wider implementation with various techniques to tension the suture tape. Examining the potential biomechanical sequelae of the UCL repair construct applied under maximal tension will help further refine recommendations for surgeons who utilize this technique for UCL repair.

Material Properties of Fiber Bundles of the Superficial Medial Collateral Ligament of the Knee Joint.

The superficial medial collateral ligament (sMCL) of the human knee joint has functionally separate anterior and posterior fiber bundles. The two bundles are alternatively loaded as the knee flexion angle changes during walking. To date, the two bundles are usually not distinguished in knee ligament simulations because there has been little information about their material properties. In this study, we conducted quasi-static tensile tests on the sMCL of matured porcine stifle joints and obtained the material properties of the anterior bundle (AB), posterior bundle (PB), and whole ligament (WL). AB and PB have similar failure stress but different threshold strain, modulus, and failure strain. As a result, we recommend assigning different material properties (i.e., modulus and failure strain) to the two fiber bundles to realize biofidelic ligament responses in human body models. However, it is often inconvenient to perform tensile tests on AB and PB. Hence, we proposed a microstructural model-based approach to predict the material properties of AB and PB from the test results of WL. Such obtained modulus values of AB and PB had an error of 2% and 0.3%, respectively, compared with those measured from the tests. This approach can reduce the experimental cost for acquiring the needed mechanical property data for simulations.

Release or transection of superficial medial collateral ligament during open-wedge high tibial osteotomy demonstrated similar clinical outcomes and valgus laxity.

PURPOSE: To analyse whether valgus laxity and clinical outcomes differ depending on whether the superficial medial collateral ligament (sMCL) is released or transected during medial open-wedge high tibial osteotomy (MOWHTO). METHODS: Consecutive patients who underwent MOWHTO and subsequent radiological follow-up for at least 2 years were retrospectively evaluated. The patients were divided into release and transection groups, according to the sMCL manipulation technique. Each patient was assessed for the following variables on valgus stress radiographs taken before surgery and at the 12- and 24-month follow-ups: the absolute value of valgus (ABV) and side-to-side difference (SSD) between the affected and normal sides. The differences between preoperative SSD and those at 12 and 24 months were respectively calculated and defined as delta SSD (ΔSSD). The Visual Analogue Scale, Lysholm knee, International Knee Documentation Committee subjective, and Knee Injury and Osteoarthritis Outcome scores were used to evaluate patient-reported outcomes. RESULTS: Eighty-five patients were included in the study. Forty-two patients (49.6%) underwent sMCL release, and the remaining 43 patients (50.4%) underwent sMCL transection. No significant differences were observed in the ABV and SSD of valgus laxity at the different time points between the two groups (n.s.). Furthermore, no significant differences were observed in the ΔSSD at the 12- and 24-month follow-ups between the two groups (n.s.). Significant improvement from preoperative values was observed in all patient-reported outcomes (p < 0.001), with no significant differences between the two groups at any time point (n.s.). CONCLUSION: Significant improvements in clinical outcomes were observed, regardless of the technique used. Postoperative valgus laxity did not occur with either technique. The transection technique, which can be performed more simply and quickly, demonstrated similar clinical outcomes and valgus laxity to the release technique. LEVEL OF EVIDENCE: Level III.

Simple acute postero-lateral elbow dislocation: A historical perspective.

PURPOSE: The aims of this study were to summarize (1) the historical knowledge of the posterolateral elbow dislocation (PLED) pattern and the biomechanical, radiographic, and clinical data that engendered its evolution; and (2) to help clinicians better understand the management of PLED. METHODS: A literature search was performed using Ovid, Scopus and Cochrane Library, and the Medical Subject Headings vocabulary. Results are discussed as a chronologic review of the relevant literature between 1920-2022. RESULTS: In 1966 Osborn and Cotterill were the first to describe posterolateral rotatory instability (PLRI) causing the PLED. Several theories on PLED were then published by others surgeons as our understanding of elbow biomechanics continued to improve. Multiple treatment protocols have been designed based on the aforementioned theories. Conservative and surgical treatment for PLED provides excellent functional outcomes. However, high rates of persistent pain stiffness and instability have been reported long-term, and no single approach to treatment has been widely accepted. CONCLUSION: Despite a growing body of biomechanical evidence, there is no consensus surgical indication for the treatment of PLED. Both conservative and surgical management result in satisfactory functional outcomes after PLED. However, elevated rates of residual pain, and instability have also been described and may limit heavy labor and sports participation. The next challenge for elbow surgeons will be to identify those patients who would benefit from surgical stabilization following PLED.

Shear wave elastography demonstrates different material properties between the medial collateral ligament and anterolateral ligament.

BACKGROUND: Anterolateral ligament and medial collateral ligament injuries could happen concomitantly with anterior cruciate ligament ruptures. The anterolateral ligament is injured more often than the medial collateral ligament during concomitant anterior cruciate ligament ruptures although it offers less restraint to knee movement. Comparing the material properties of the medial collateral ligament and anterolateral ligament helps improve our understanding of their structure-function relationship and injury risk before the onset of injury. METHODS: Eight cadaveric lower extremity specimens were prepared and mechanically tested to failure in a laboratory setting using a hydraulic platform. Measurements of surface strains of superficial surface of each medial collateral ligament and anterolateral ligament specimen were found using three-dimensional digital image correlation. Ligament stiffness was found using ultrasound shear-wave elastography. t-tests were used to assess for significant differences in strain, stress, Young's modulus, and stiffness in the two ligaments. FINDINGS: The medial collateral ligament exhibited greater ultimate failure strain along its longitudinal axis (p = 0.03) and Young's modulus (p < 0.0018) than the anterolateral ligament. Conversely, the anterolateral ligament exhibited greater ultimate failure stress than the medial collateral ligament (p < 0.0001). Medial collateral ligament failure occurred mostly in the proximal aspect of the ligament, while most anterolateral ligament failure occurred in the distal or midsubstance aspect (P = 0.04). INTERPRETATION: Despite both being ligamentous structures, the medial collateral ligament and anterolateral ligament exhibited separate material properties during ultimate failure testing. The weaker material properties of the anterolateral ligament likely contribute to higher rates of concomitant injury with anterior cruciate ligament ruptures.

Arthroscopic assessment for lateral collateral ligament complex deficiency of the elbow: a cadaveric study.

PURPOSE: To evaluate whether elbow instability due to lateral collateral ligament complex injury can be assessed reliably through arthroscopy. METHODS: Eight fresh human cadaveric elbows were placed in a simulated lateral decubitus position. The radiocapitellar joint (RCJ) gap and ulnohumeral joint (UHJ) gap (mm) were measured with different sizes of probes from the posterolateral viewing portal. The elbow was 90 degrees flexed with neutral forearm rotation for RCJ gap measurement and 30 degrees flexed with full supination for UHJ gap measurement. Sequential testing was performed from Stage 0 to Stage 3 (Stage 0: intact; Stage 1: the release of the anterior 1/3 LCL complex; Stage 2: the release of the anterior two thirds of the LCL complex; and Stage 3: the release of the entire LCL complex) on each specimen. The mean gap of RCJ and lateral UHJ was used for the comparison between stages with the intact elbow. RESULTS: The mean RCJ gap distance in Stage 2 and Stage 3 was significantly increased compared to that in Stage 0 (Stage 0 vs. Stage 2: P = .008; Stage 0 vs. Stage 3: P = .010). The mean UHJ gap distance of Stage 1, Stage 2, and Stage 3 was significantly increased compared to that in Stage 0 (Stage 0 vs. Stage 1: P = 0.025; Stage 0 vs. Stage 2: P = .010; Stage 0 vs. Stage 3: P = .011). In contrast, the release of the anterior 1/3 of the LCL complex (Stage 1) was not significantly increased compared to the mean joint gap distance of RCJ (P = .157). CONCLUSION: Arthroscopic measurement of joint gap widening in RCJ and UHJ is a reliable assessment method to detect LCL complex deficiency that involves the anterior two thirds or more.

Graft choice and techniques used in elbow ulnar collateral ligament reconstruction over the last 20 years: a systematic review and meta-analysis.

BACKGROUND: Elbow medial ulnar collateral ligament (mUCL) injuries have become increasingly common, leading to a higher number of mUCL reconstructions (UCLR). Various techniques and graft choices have been reported. The purpose of this study was to evaluate the prevalence of each available graft choice, the surgical techniques most utilized, and the reported complications associated with each surgical method. METHODS: A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysesguidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify all articles that included UCLR between January 2002 and October 2022. We included all studies that referenced UCLR graft choice, surgical technique, and/or ulnar nerve transposition. Studies were evaluated in a narrative fashion to assess demographics and report current trends in utilization and complications of UCLR as they pertain to graft choice and surgical techniques over the past 20 years. Where possible, we stratified based on graft and technique. RESULTS: Forty-seven articles were included, reporting on 6671 elbows. The cohort was 98% male, had a weighted mean age of 21 years and follow-up of 53 months. There were 6146 UCLRs (92%) performed with an autograft and 152 (2.3%) that utilized an allograft, while 373 (5.6%) were from mixed cohorts of autograft and allograft. Palmaris longus autograft was the most utilized mUCL graft choice (64%). The most utilized surgical configuration was the figure-of-8 (68%). Specifically, the most common techniques were the modified Jobe technique (37%), followed by American Sports Medicine Institute (ASMI) (22%), and the docking (22%) technique. A concomitant ulnar nerve transposition was performed in 44% of all patients, with 1.9% of these patients experiencing persistent ulnar nerve symptoms after ulnar nerve transposition. Of the total cohort, 14% experienced postoperative ulnar neuritis with no prior preoperative ulnar nerve symptoms. Further, meta-analysis revealed a significantly greater revision rate with the use of allografts compared to autograft and mixed cohorts (2.6% vs. 1.8% and 1.9%, P = .003). CONCLUSIONS: Most surgeons performed UCLR with palmaris autograft utilizing a figure-of-8 graft configuration, specifically with the modified Jobe technique. The overall rate of allograft use was 2.3%, much lower than expected. The revision rate for UCLR with allograft appears to be greater compared to UCLR with autograft, although this may be secondary to limited allograft literature.

The posterolateral ligament of the elbow: anatomy and clinical relevance.

BACKGROUND: The posterolateral capsule was recognized in the past as an important structure for elbow stability but was later disregarded. Two recent biomechanical studies demonstrated its role in preventing posterolateral instability, and thus it should be identified as a distinct ligament: the posterolateral ligament (PLL). This study includes 2 parts: an anatomic study of the PLL's footprint and a collection of 5 cases of pathologic lesions of the PLL. METHODS: Six cadaveric upper limbs were assessed. The attachments of the PLL were dissected, the footprints were marked and photographed, and the 2-dimensional area and length were measured. RESULTS: The mean proximal attachment dimensions were a length of 13 mm and an area of 101 mm2, and the mean distal attachment dimensions were 19 mm and 111 mm2, respectively. There were 2 cases of posterolateral elbow pain in professional cricket bowlers, diagnosed radiographically as enthesopathy of the PLL's proximal attachment on the posterior capitellum, probably due to repeated forced hyperextension of the elbow. Both patients were treated by débridement of the posterior capitellum and reattachment of the PLL, with complete resolution of symptoms. In addition, there were 3 cases of clinical posterolateral rotatory instability in young patients. Two athletes had an isolated acute tear of the PLL, and on physical examination, both had positive posterior draw test results but negative pivot-shift test results. Both underwent elbow arthroscopy and repair of the PLL with resolution of symptoms. The third patient had long-standing recurrent elbow instability, following a failed lateral ulnar collateral ligament reconstruction, in the presence of an Osborne-Cotterill lesion. He underwent revision lateral ulnar collateral ligament reconstruction, bone grafting of the bony lesion, and reattachment of the PLL, with complete resolution of symptomatic posterolateral rotatory instability. CONCLUSIONS: The PLL of the elbow has a significant role in the elbow's posterolateral stability. Its footprints were described, and its clinical significance was demonstrated in cases of elbow instability caused by acute ligament tears and elbow pain due to ligament enthesopathy. Surgeons should be aware of this structure and potential pathology related to its injury.

High Prevalence of Superficial and Deep Medial Collateral Ligament Injuries on Magnetic Resonance Imaging in Patients With Anterior Cruciate Ligament Tears.

PURPOSE: To assess the prevalence of and factors associated with medial collateral ligament (MCL) complex injuries on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears. METHODS: Data were extracted from the Natural Corollaries and Recovery After ACL Injury (NACOX) multicenter longitudinal cohort study. Between May 2016 and October 2018, patients who presented to 1 of 7 health care clinics across Sweden with an ACL tear sustained no more than 6 weeks earlier and who were aged between 15 and 40 years at the time of injury were invited to participate. All the patients included in this study underwent MRI. The mean time from injury to MRI was 19.6 ± 15.2 days. An orthopaedic surgeon specializing in knee surgery and a musculoskeletal radiologist reviewed all MRI scans. Injuries to the superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament were identified. Stepwise forward multiple binary logistic regression analyses were used to evaluate patient characteristics (age, sex, body mass index, preinjury Tegner activity level, and activity at injury) and injuries on MRI (lateral meniscus [LM] injury, medial meniscus [MM] injury, pivot shift-type bone bruising, medial femoral condyle [MFC] bone bruising, and lateral femoral condyle [LFC] impaction) associated with the presence of MCL complex tears. RESULTS: In total, 254 patients (48.4% male patients) with a mean age of 25.4 ± 7.1 years were included. The overall prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries was 16.5% (42 of 254) and 24.8% (63 of 254), respectively. No isolated sMCL injuries were found. Posterior oblique ligament injuries were found in 12 patients (4.7%) with MCL (sMCL and dMCL) injuries. An LM injury (odds ratio [OR], 3.94; 95% confidence interval [CI], 1.73-8.94; P = .001) and LFC impaction (OR, 2.37; 95% CI, 1.11-5.07; P = .02) increased the odds of having an MCL injury, whereas an MM injury (OR, 0.26; 95% CI, 0.12-0.59; P = .001) reduced the odds. Isolated dMCL injuries were significantly associated with MFC bone bruising (OR, 4.21; 95% CI, 1.92-9.25; P < .001) and LFC impaction (OR, 3.86; 95% CI, 1.99-7.49; P < .001). CONCLUSIONS: The overall combined prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries in patients with ACL tears was high (16.5% + 24.8% = 41.3%). The presence of an LM injury and LFC impaction increased the odds of having an MCL injury, whereas the presence of an MM injury reduced the odds. MFC bone bruising and LFC impaction were associated with the presence of isolated dMCL injuries. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

The distance between the fibular collateral ligament tunnel and the common peroneal nerve allows a posterolateral corner reconstruction without neurolysis.

PURPOSE: The most popular knee posterolateral corner (PLC) reconstruction techniques describe that a common peroneal nerve (CPN) neurolysis must be done to safely address the posterolateral aspect of the knee. The purpose of this study was to measure the distance between the CPN and the fibular insertion of the FCL in different degrees of knee flexion in cadaveric specimens, to identify if tunnel drilling could be done anatomically and safely without a CPN neurolysis. METHODS: Ex vivo experimental analytical study. Ten fresh frozen human knees were dissected leaving FCL and CPN in situ. Shortest distance from the centre of the FCL distal tunnel and CPN was measured (antero-posterior and proximal-distal wire-nerve distances) at 90°, 60°, 30°, and 0° of knee flexion. Measurements between different flexion angles were compared and correlation between knee flexion angle and distance was identified. RESULTS: The mean distance between the FCL tunnel and the CPN at 90° were 21.15 ± 6.74 mm posteriorly (95% CI: 16.33-25.97) and 13.01 ± 3.55 mm distally (95% CI: 10.47-15.55). The minimum values were 9.8 mm posteriorly and 8.9 mm, respectively. These distances were smaller at 0° (p ≤ 0.017). At 90° of knee flexion, the mean distance from the fibular tip to the CPN distally was 23.46 ± 4.13 mm (20.51-26.41). CONCLUSION: Anatomic localization and orientation of fibular tunnels can be done safely while avoiding nerve neurolysis. Further studies should aim to in vivo measurements and results.