Augmented Ulnar Collateral Ligament Repair With Structural Bioinductive Scaffold: A Biomechanical Study.

BACKGROUND: Elbow ulnar collateral ligament (UCL) repair with suture brace augmentation shows good time-zero biomechanical strength and a more rapid return to play compared with UCL reconstruction. However, there are concerns about overconstraint or stress shielding with nonabsorbable suture tape. Recently, a collagen-based bioinductive absorbable structural scaffold has been approved by the Food and Drug Administration for augmentation of soft tissue repair. PURPOSE/HYPOTHESIS: This study aimed to assess the initial biomechanical performance of UCL repair augmented with this scaffold. We hypothesized that adding the bioinductive absorbable structural scaffold to primary UCL repair would impart additional time-zero restraint to the valgus opening. STUDY DESIGN: Controlled laboratory study. METHODS: Eight cadaveric elbow specimens-from midforearm to midhumerus-were utilized. In the native state, elbows underwent valgus stress testing at 30o, 60o, and 90o of flexion, with a cyclical valgus rotational torque. Changes in valgus rotation from 2- to 5-N·m torque were recorded as valgus gapping. Testing was then performed in 4 states: (1) native intact UCL-with dissection through skin, fascia, and muscle down to an intact UCL complex; (2) UCL-transected-distal transection of the ligament off the sublime tubercle; (3) augmented repair with bioinductive absorbable scaffold; and (4) repair alone without scaffold. The order of testing of repair states was alternated to account for possible plastic deformation during testing. RESULTS: The UCL-transected state showed the greatest increase in valgus gapping of all states at all flexion angles. Repair alone showed similar valgus gapping to that of the UCL-transected state at 30° (P = .62) and 60° of flexion (P = .11). Bioinductive absorbable scaffold-augmented repair showed less valgus gapping compared with repair alone at all flexion angles (P = .021, P = .024, and P = .024 at 30°, 60°, and 90°, respectively). Scaffold-augmented repair showed greater gapping compared with the native state at 30° (P = .021) and 90° (P = .039) but not at 60° of flexion (P = .059). There was no difference when testing augmented repair or repair alone first. CONCLUSION: UCL repair augmented with a bioinductive, biocomposite absorbable structural scaffold imparts additional biomechanical strength to UCL repair alone, without overconstraint beyond the native state. Further comparative studies are warranted. CLINICAL RELEVANCE: As augmented primary UCL repair becomes more commonly performed, use of an absorbable bioinductive scaffold may allow for improved time-zero mechanical strength, and thus more rapid rehabilitation, while avoiding long-term overconstraint or stress shielding.

Clinical outcomes after primary repair for thumb ulnar collateral ligament ruptures: a systematic review and meta-analysis.

There is no consensus on the best surgical technique for treating thumb ulnar collateral ligament (UCL) ruptures. This systematic review and meta-analysis investigates which primary repair technique and postoperative immobilization protocol result in the best clinical outcomes. A literature search was conducted in Embase, Medline ALL Ovid, Web of Science Core Selection and Cochrane Central Register of Controlled Trials. Pain, stability, tip pinch strength, key pinch strength, grip strength, return to work and metacarpophalangeal joint range of motion were collected as postoperative outcomes. In total, 29 studies were included. All surgical techniques resulted in satisfactory clinical outcomes, with no significant differences between bone anchor reinsertion, suture fixation, K-wire fixation and a combination of techniques. K-wire immobilization resulted in worse postoperative pain, but similar stability compared to immobilization without a K-wire. Clinical outcomes after thumb UCL repair are excellent, with no differences in clinical outcomes noted among surgical techniques.

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.

Biomechanical Characteristics of Ulnar Collateral Ligament Injuries Treated With and Without Augmentation: A Network Meta-analysis of Controlled Laboratory Studies.

BACKGROUND: Treatment of ulnar collateral ligament (UCL) tears with suture tape augmentation has gained interest given preliminary reports of favorable biomechanical characteristics. No study to date has quantitatively assessed the biomechanical effects of multiple augmentation techniques relative to the native UCL. PURPOSE: To perform a systematic review and meta-analysis of controlled laboratory studies to assess and comparatively rank biomechanical effects of UCL repair or reconstruction with or without augmentation. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: PubMed, OVID/Medline, and Cochrane databases were queried in January 2023. A frequentist network meta-analytic approach was used to perform mixed-treatment comparisons of UCL repair and reconstruction techniques with and without augmentation, with the native UCL as the reference condition. Pooled treatment estimates were quantified under the random-effects assumption. Competing treatments were ranked in the network meta-analysis by using point estimates and standard errors to calculate P scores (greater P score indicates superiority of treatment for given outcome). RESULTS: Ten studies involving 206 elbow specimens in which a distal UCL tear was simulated were included. UCL reconstruction with suture tape augmentation (AugRecon) restored load to failure to a statistically noninferior magnitude (mean difference [MD], -1.99 N·m; 95% CI, -10.2 to 6.2 N·m; P = .63) compared with the native UCL. UCL reconstruction (Recon) (MD, -12.7 N·m; P < .001) and UCL repair with suture tape augmentation (AugRepair) (MD, -14.8 N·m; P < .001) were both statistically inferior to the native UCL. The AugRecon condition conferred greater load to failure compared with Recon (P < .001) and AugRepair (P = .002) conditions. AugRecon conferred greater torsional stiffness relative to all other conditions and was not statistically different from the native UCL (MD, 0.32 N·m/deg; 95% CI, -0.30 to 0.95 N·m/deg; P = .31). Medial ulnohumeral gapping was not statistically different for the AugRepair (MD, 0.30 mm; 95% CI, -1.22 to 1.82 mm; P = .70), AugRecon (MD, 0.57 mm; 95% CI, -0.70 to 1.84 mm; P = .38), or Recon (MD, 1.02 mm; 95% CI, -0.02 to 2.05 mm; P = .055) conditions compared with the native UCL. P-score analysis indicated that AugRecon was the most effective treatment for increasing ultimate load to failure and torsional stiffness, whereas AugRepair was the most effective for minimizing medial gapping. CONCLUSION: AugRecon restored load to failure and torsional stiffness most similar to the parameters of the native UCL, whereas Recon and AugRepair did not restore the same advantageous properties at time zero. Medial ulnohumeral gapping during a valgus load was minimized by all 3 treatments. Based on network interactions, AugRecon was the superior treatment approach for restoring important biomechanical features of the UCL at time zero that are jeopardized during a complete distal tear.

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.

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.

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.

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.

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.

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.

Similar return to sport between double cortical button and docking techniques for ulnar collateral ligament reconstruction in baseball players.

BACKGROUND AND HYPOTHESIS: A double cortical button technique for ulnar collateral ligament reconstruction (UCLR) has advantages including significant control over graft tensioning, less concern about graft length, and minimized risk of bone tunnel fracture compared with traditional UCLR techniques. This double cortical button technique was recently found to be noninferior in mechanical performance to the traditional docking technique regarding joint strength, joint stiffness, and graft strain. However, clinical outcomes have not been compared between these UCLR techniques. Therefore, the purpose of this study was to determine whether baseball players who underwent UCLR with a double cortical button (double button) technique have similar return-to-sport (RTS) outcomes to baseball players who underwent UCLR with the traditional docking (docking) technique. MATERIALS AND METHODS: Baseball players who underwent primary UCLR from 2011 to 2020 across 2 institutions were identified. Included patients were contacted to complete a follow-up survey evaluating reoperations, RTS, and functional outcome scores. Functional outcome surveys include the Kerlan-Jobe Orthopaedic Clinic score, the Conway-Jobe score, the Andrews-Timmerman elbow score, and the Single Assessment Numeric Evaluation score. RESULTS: Overall, 78 male baseball players (age: 18.9 ± 2.4 years) with an average follow-up of 3.1 ± 2.4 years were evaluated, with 73 of the players being baseball pitchers. Players in the double button group more frequently received palmaris longus autografts (78% vs. 30%) and less frequently received gracilis autografts (22% vs. 58%) compared with players in the docking group (P = .001); however, all other demographic factors were similar between the groups. All players in the double button group were able to RTS in 11.1 ± 2.6 months, whereas 96% of players in the docking group were able to RTS in 13.5 ± 3.4 months (P > .05). All postoperative outcomes and patient-reported outcomes were statistically similar between the groups and remained similar after isolating pitchers only and after separating partial-thickness from full-thickness UCL tears (all P > .05). CONCLUSION: RTS and other postoperative outcomes may be similar between baseball players who underwent UCLR with the double button technique and the docking technique. Although future research may be necessary to strengthen clinical recommendations, these findings provide the first clinical outcomes in light of a recent cadaveric study finding similar elbow strength, joint stiffness, and graft strain compared with the docking technique.

Characterizing focal muscle signal on MRI in flexor-pronator muscles' status post ulnar collateral ligament reconstruction.

OBJECTIVE: Focal high signal is commonly seen about the flexor pronator mass on MRI in some patients after ulnar collateral ligament (UCL) reconstruction of the elbow. The etiology of this high signal is unclear and not described in literature. The hypothesis is that the edema we see on post-operative MRI is related to palmaris longus graft harvest rather than secondary to other causes of muscle edema such as denervation or muscle strain. METHODS AND MATERIALS: An IRB waiver-approved, retrospective search of our radiology database was conducted using the keywords "ucl," "elbow," and "reconstruction" between 1/01/2012 and 1/01/2022, with search parameters set as MRI for exam type. The images were reviewed to evaluate for high signal at the flexor pronator mass by a junior and a senior musculoskeletal radiologist. The surgical notes were then reviewed in electronic medical record system to see which graft was used for the UCL reconstruction. RESULTS: The cohort comprised of 33 patients (1 female/32males, 14-51 years old) who had undergone UCL reconstructions. Four patients were excluded from the study secondary to the surgical note not specifying which graft was used. The surgical and imaging dates were also recorded with the largest time gap of 7 years between the surgery and imaging. Seventeen of the 29 patients had palmaris longus harvested from the ipsilateral arm, 1 patient had palmaris longus harvested from the contralateral arm, 2 patients had an internal brace, and 9 patients had a hamstring graft. Seventeen out of 17 (100%) patients with ipsilateral palmaris longus graft demonstrated focal edema at the flexor pronator mass while 0/12 of the patients without the palmaris longus graft showed the focal edema seen by its counterparts. CONCLUSION: High signal which is commonly seen at the flexor pronator mass in patient status most UCL reconstruction of the elbow is secondary to the palmaris longus harvest rather than other etiologies such as muscle strain, retear, or trauma.

Rehabilitation of the painful elbow.

Although lateral elbow pain and medial ulnar collateral ligament injury are common musculoskeletal pathologies in overhead athletes, the evidence supporting specific interventions for managing these conditions is scarce. Management of these conditions has been guided mostly by expert opinion rather than empirical evidence, yet the lack of comparative data in the literature has not negatively affected return-to-play rates following surgery. However, an understanding of what is known regarding unimodal and multimodal treatments for lateral elbow pain and medial ulnar collateral ligament injury is needed for clinicians to select evidence-based treatment pathways and highlight what is not known to develop future high-quality investigations.

Elbow Ulnar Collateral Ligament Repair With Suture Augmentation Is Biomechanically Equivalent to Reconstruction and Clinically Demonstrates Excellent Outcomes: A Systematic Review.

PURPOSE: To systematically review (1) biomechanical properties of augmented elbow ulnar collateral ligament (UCL) repair compared with reconstruction and (2) clinical efficacy and complication rates of UCL repair with and without augmentation. METHODS: A systematic review was completed August 15, 2023, identifying articles that (1) biomechanically compared suture augmented UCL repair and reconstruction and (2) clinically evaluated medial elbow UCL repairs. Search terms included: "UCL repair" OR "internal brace" OR "suture augmentation" AND "UCL reconstruction." For inclusion, biomechanical studies compared augmented repair with reconstruction; clinical studies required clinical outcomes with minimum 6-month follow-up. Biomechanical data included torsional stiffness, gap formation, peak torque, and failure torque. Clinical data included return to previous level of play, time to return, functional outcomes, and complications. RESULTS: In total, 8 biomechanical and 9 clinical studies were included (5 with and 4 without augmentation). In most biomechanical studies, augmented repairs demonstrated less gap formation, with equivalent torsional stiffness, failure load, and peak torque compared with reconstruction. Clinical outcomes in 104 patients without augmentation demonstrated return to previous level of 50% to 94% for nonprofessional athletes and 29% for professional baseball pitchers. Suture augmented repairs in 554 patients demonstrated return to previous level from 92% to 96%, at 3.8 to 7.4 months, with Kerlan Jobe Orthopaedic Clinic scores of 86 to 95. The overall complication rate for augmented UCL repair was 8.7%; most commonly ulnar neuropraxia (6%). CONCLUSIONS: Biomechanically, UCL repair with augmentation provided less gapping with equivalent torsional stiffness and failure compared with reconstruction. Clinically, augmented UCL repair demonstrated excellent return to previous level of play and Kerlan Jobe Orthopaedic Clinic scores with modest complications and time to return. Augmented UCL repair is biomechanically equivalent to reconstruction and may be a viable alternative to reconstruction in indicated athletes. CLINICAL RELEVANCE: UCL repair with suture augmentation is biomechanically equivalent to reconstruction and clinically demonstrates excellent outcomes.

In Vivo Effect of Partial Ulnar Collateral Ligament Tear Location on Ulnohumeral Joint Gapping With Stress Ultrasound in Baseball Pitchers.

BACKGROUND: Stress ultrasonography (SUS) has provided clinicians with an alternative means of evaluating ulnar collateral ligament (UCL) injury by dynamically assessing ulnohumeral joint space gapping under applied valgus stress. However, 3 previous cadaveric studies have evaluated the biomechanical effect of partial UCL tears at different anatomic locations with conflicting results. PURPOSE/HYPOTHESIS: The purpose of this study was to use in vivo data from patients with magnetic resonance (MR)-confirmed partial UCL tears to determine if anatomic partial tear location influenced the resultant stability of the elbow in terms of ulnohumeral joint gapping on SUS. It was hypothesized that no difference would be seen in the amount of ulnohumeral joint gapping based on MR-identified anatomic partial UCL tear location. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients diagnosed with elbow injury from 2015 to 2020 were screened to identify competitive baseball pitchers with a partial UCL tear who received an SUS. Partial UCL tear was diagnosed via surgeon and radiologist interpretation of elbow MR imaging (MRI) as well as confirmation at the time of surgery as documented in the operative report. Demographic, injury, and treatment data were collected from the clinic notes, MRI reports, and stress ultrasound reports. Ulnohumeral joint gapping on SUS was calculated as the difference between ulnohumeral joint gapping without valgus stress versus ulnohumeral joint gapping with valgus stress (delta) as performed by a musculoskeletal radiologist. RESULTS: Overall, 60 male baseball pitchers (age, 19.2 ± 2.1 years), including 22 (37%) high school, 26 (43%) collegiate, and 12 (20%) professional pitchers, were evaluated. Regarding the location of partial UCL tears, 32 (53%) pitchers had proximal tears and 28 (47%) had distal tears. The mean delta value cohort was 2.1 ± 1.1 mm, and 34 pitchers (57%) had delta values >2.0 mm. Ulnohumeral joint gapping (high school [1.9 mm] vs collegiate [2.6 mm] vs professional [1.6 mm]; P = .004) and the percentage of pitchers with delta values >2.0 mm (45% vs 77% vs 33%; P = .017) differed based on level of competition. After controlling for age, body mass index, and level of competition in a multivariate linear regression, tear location was not related to ulnohumeral joint gapping (P = .499). CONCLUSION: No difference was observed in the amount of ulnohumeral joint gapping on SUS in symptomatic baseball pitchers with MR-identified partial UCL tears at differing anatomic locations. The findings of this study are contrary to previous cadaveric studies that have evaluated the effects of UCL tear characteristics on delta laxity.

Biomechanical Properties of Knee Medial Collateral Ligament Compared to Palmaris Longus for Ulnar Collateral Ligament Reconstruction.

Ulnar collateral ligament reconstruction (UCLR) is frequently performed among injured overhead-throwing athletes. One of the most common graft choices when performing a UCLR is the ipsilateral palmaris longus tendon (PL). The purpose of this study was to investigate the material properties of aseptically processed cadaveric knee collateral ligaments (kMCL) as a potential graft source for UCLR and compare them to the gold standard PL autograft. Each PL and kMCL cadaveric sample was subjected to cyclic preconditioning, stress relaxation, and load-to-failure testing, and the mechanical properties were recorded. PL samples exhibited a greater average decrease in stress compared to the kMCL samples during the stress-relaxation test (p < 0.0001). PL samples also demonstrated a greater average Young's modulus in the linear region of the stress-strain curve compared to the kMCL samples (p < 0.01). The average yield strain and maximum strain of kMCL samples were significantly greater than the PL, p = 0.03 and 0.02, respectively. Both graft materials had comparable maximum toughness and demonstrated a similar ability to deform plastically without rupture. The clinical significance of our result is that prepared knee medial collateral ligament allografts may provide a viable graft material for use in the reconstruction of elbow ligaments.

Editorial Commentary: Diagnosis, Treatment, Rehabilitation and Return to Sport After Ulnar Collateral Ligament Injury: Agreement Does not Equal Consensus.

Tommy John surgical reconstruction for ulnar collateral ligament injuries was first described by Frank Jobe in 1974. Although he estimated the chance for successful return very low, John, famous baseball pitcher, was able to return to play for another 14 years. Modern techniques and better understanding of anatomy and biomechanics have now resulted in a return-to-play rate of more than 80%. Ulnar collateral ligament injuries occur mainly in overhead athletes. Generally, partial tears can be treated nonoperatively, but in baseball pitchers, success rates are less than 50%. Complete tears often require surgery. Primary repair or reconstruction are feasible options, and the choice will depend not only on the clinical scenario, but also the surgeon. Unfortunately, the current evidence is not convincing, and a recent expert consensus study exploring diagnosis, treatment options, rehabilitation, and return to sports showed agreement among the experts, but not necessarily a consensus.

Inconsistencies in reporting risk factors for ulnar collateral ligament reconstruction failure: a systematic review.

BACKGROUND: When return to sport (RTS) at a competitive level is desired, treatment of injury to the ulnar collateral ligament (UCL) frequently involves surgical reconstruction. Although RTS rates between 66% and 98% have been reported, there remains a paucity of comparative clinical studies, with far fewer reporting statistically significant risk factors for reconstruction failure. The goal of this study was to perform a systematic review of the literature to demonstrate the variety and inconsistency with which risk factors associated with reconstruction failure are reported. MATERIALS AND METHODS: A systematic review of the PubMed Central and MEDLINE databases was performed to identify clinical outcome studies reporting ≥1 statistically significant risk factor associated with failure of UCL reconstruction. Failure was defined as (1) reinjury, recurrent instability, or need for revision surgery; (2) failure show improvement in postoperative patient-reported outcomes (PROs); or (3) failure to RTS at the preinjury level (RSL). RESULTS: A total of 349 unique studies were initially identified, of which 12 were deemed eligible for inclusion in our study. Of these 12 studies, 4 defined outcomes based on recurrent instability, reinjury, or revision surgery; 2 defined outcomes based on PROs; and 6 defined outcomes based on RSL. In the group with instability, reinjury, or revision failure, 11 significant risk factors were identified across all studies: age, height, body mass index, professional experience, injury to the nondominant arm, history of competitive throwing, mechanism of injury, history of a psychiatric diagnosis, presence of preoperative instability or stiffness, postoperative workload, and time to RTS. In the PRO failure group, 12 risk factors were identified across all studies: age, status as a military cadet, injury to the nondominant arm, graft type, baseball position, current injury to the ipsilateral arm, current level of competition attributed to reconstruction surgery, shoulder surgery after reconstruction, no competitive throwing history, non-throwing mechanism of injury, history of a psychiatric diagnosis, and preoperative instability or stiffness. In the RSL failure group, 4 risk factors were identified across all studies: age, ulnar neuritis, level of professional play, and amount of time spent at the professional level. CONCLUSIONS: Age, level of professional play prior to surgery, postoperative workload, and time at the professional level are the most commonly reported risk factors associated with UCL reconstruction failure. There remains a paucity of data associating risk factors with patient-specific outcomes and marked levels of inconsistency and conflict among the studies that report such data.

Biomechanical Stability of Lateral Ulnar Collateral Ligament Reconstruction and Repair of the Elbow: The Role of Ligament Bracing on Gap Formation and Stabilization.

BACKGROUND: Augmented (internal braced) lateral ulnar collateral ligament (LUCL) repair has been biomechanically compared with reconstruction techniques in the elbow. However, LUCL repair alone has not yet been compared with augmented repair and reconstruction techniques. HYPOTHESIS: Internal bracing of LUCL repair would improve time-zero stabilization regarding gap formation, stiffness, and residual torque as compared with repair alone and reconstruction techniques to restore native elbow stability. STUDY DESIGN: Controlled laboratory study. METHODS: Overall, 24 cadaveric elbows were used for either internal braced LUCL repair (Repair-IB) or single- and double-strand ligament reconstruction with triceps (Recon-TR) and palmaris longus tendon graft (Recon-PL), respectively. Laxity testing in external rotation was consecutively performed at 90° of elbow flexion on the intact, dissected, and repaired conditions and with the previously assigned techniques. First, intact elbows were loaded to 7.0-N·m external torque to evaluate time-zero ligament rotations at 2.5, 4.0, 5.5, and 7.0 N·m. Rotation-controlled cycling was performed (total of 1000 cycles) for each surgical condition. Gapping, stiffness, and residual torque were analyzed. Finally, these and 8 additional intact elbows underwent torque-to-failure testing (30 deg/min). RESULTS: The dissected state showed the highest gap formation and lowest peak torques (P < .001). While gap formation of Repair-IB (P < .021) was significantly lower than that of repair without internal bracing at all rotation levels, gaps of Recon-PL were similar to and Recon-TR were significantly higher than those of Repair-IB except for the highest torsion level. Residual peak torques at specific rotation angles between native state and Recon-TR (α2.5), Recon-PL (α4.0), and Repair-IB (α5.5) were similar; all other comparisons were significantly different (P < .027). Torsional stiffness of Repair-IB was significantly higher at all rotation angles measured. Analysis of covariance showed significantly less gap formation over residual peak torques for Repair-IB (P < .001) as compared with all other groups. The native state failure load was significantly higher than Recon-PL and Recon-TR failure loads, with similar stiffness to all other groups. CONCLUSION: Repair-IB and Recon-PL of the LUCL showed increased rotational stiffness relative to the intact elbow for restoring posterolateral stability to the native state in a cadaveric model. Recon-TR demonstrated lower residual peak torques but provided near-native rotational stiffness. CLINICAL RELEVANCE: Internal bracing of LUCL repair may reduce suture-tearing effects through tissue and provide sufficient stabilization for healing throughout accelerated and reliable recovery without the need for a tendon graft.

Return to Sport After Nonoperative Management of Elbow Ulnar Collateral Ligament Injuries: A Systematic Review and Meta-analysis.

BACKGROUND: Elbow ulnar collateral ligament (UCL) injuries can result in significant functional impairment in throwing and overhead athletes. UCL reconstruction and repair are proven treatments to restore stability, but the efficacy of nonoperative management is unclear. PURPOSE: To determine the rate of return to sports (RTS) and return to previous level of play (RTLP) in athletes sustaining medial elbow ulnar collateral ligament (UCL) injuries treated nonoperatively. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A literature search was performed using Scopus, PubMed, Medline, the Cochrane Database for Systematic Review, and the Cochrane Central Register for Controlled Trials according to the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Inclusion criteria were limited to level 1 to 4 human studies reporting on RTS outcomes after nonoperative management of UCL injuries. RESULTS: A total of 15 studies, consisting of 365 patients with a mean age of 20.45 ± 3.26 years, were identified. Treatment primarily consisted of platelet-rich plasma (PRP) injections with physical therapy (n = 189 patients; n = 7 studies) versus physical therapy alone (n = 176 patients; n = 8 studies). The overall RTS rate was 79.7% and the overall RTLP rate was 77.9%. Increasing UCL injury severity grade was associated with lower RTS rates. The RTS rate for proximal tears (89.7%; n = 61/68) was significantly greater than that for distal tears (41.2%; n = 14/34) (P < .0001). No significant difference in RTS rate was seen in patients treated with PRP versus those who did not receive PRP (P = .757). CONCLUSION: For athletes undergoing nonoperative management of UCL injuries, the overall RTS and RTLP rates were 79.7% and 77.9%, respectively, with excellent outcomes in grade 1 and grade 2 UCL injuries, specifically. The RTS rate for proximal tears was significantly higher than that for distal tears. Athletes were most commonly treated with PRP injection and physical therapy.