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.
Upper Extremity and Hip Range of Motion Changes Throughout a Season in Professional Baseball Players
Background: Loss of upper and lower extremity range of motion (ROM) is a significant risk factor for injuries in professional baseball players. Purpose/Hypothesis: The purpose was to determine changes in ROM in professional baseball players over the course of a single season and their careers. We hypothesized that pitchers and position players would lose ROM, specifically total shoulder motion (total ROM [TROM]) and hip internal rotation (IR), over the course of a season and their careers. Study Design: Case series; Level of evidence, 4. Methods: Upper and lower extremity ROM measurements were recorded during pre-, mid-, and postseason on all professional baseball players for a single organization between 2011 and 2018. ROM measurements were compared for pitchers and position players over the course of the season and their careers. Also, ROM measurements over the pre-, mid-, and postseason were compared between pitchers and position players. Results: A total of 166 professional baseball players (98 pitchers, 68 position players) were included. Pitcher hip external rotation (ER; P < .001), IR ( P = .010), and TROM ( P < .001) for lead and trail legs decreased over the course of the season. Pitcher shoulder ER ( P = .005), TROM ( P = .042), and horizontal adduction ( P < .001) significantly increased over the course of the season. Position player shoulder flexion ( P = .046), hip ER ( P < .001, lead leg; P < .001, trail leg), and hip TROM ( P = .001; P = .002) decreased over the course of the season. Position player shoulder ER ( P = .031) and humeral adduction ( P < .001) significantly increased over the course of the season. Over the course of pitchers’ careers, there was decreased shoulder IR ( P = .014), increased shoulder horizontal adduction ( P < .001), and hip IR ( P = .042) and hip TROM ( P = .027) for the lead leg. Position players experienced loss of hip TROM ( P = .010, lead leg; P = .018, trail leg) over the course of their careers. Pitchers started with and maintained more shoulder ER and gained more shoulder TROM over a season as compared with position players. Conclusion: Pitchers and position players saw overall decreases in hip ROM but increases in shoulder ROM over the course of the season and career.
Do Professional Baseball Players With a Higher Valgus Carrying Angle Have an Increased Risk of Shoulder and Elbow Injuries?
Background: There are many risk factors for shoulder and elbow injuries in professional baseball pitchers. The elbow carrying angle has not been studied as a potential risk factor. Purpose/Hypothesis: The aim of this study was to determine whether elbow carrying angle is a risk factor for shoulder or elbow injuries in professional baseball pitchers. We hypothesized that pitchers with a higher elbow carrying angle would be less likely to sustain an injury during the season than pitchers with a lower elbow carrying angle. Study Design: Cohort study; Level of evidence, 2. Methods: All professional pitchers for a single baseball club during the 2018 season had the carrying angle of both elbows measured at spring training by a single examiner. The pitchers were followed prospectively throughout the season. Shoulder and elbow injuries were recorded prospectively. Results: A total of 52 pitchers (21 [40%] Major League Baseball and 31 [60%] Minor League Baseball) were included. During the season, 23 (44%) pitchers became injured. The mean carrying angle in the throwing arm was 12.5° ± 4.2° versus 9.9° ± 2.8° in the nonthrowing arm ( P < .001). Comparing the injured and noninjured groups, there were no differences in level of play ( P = .870), throwing hand dominance ( P = .683), batting hand dominance ( P = .554), throwing-side carrying angle ( P = .373), nonthrowing-side carrying angle ( P = .773), or side-to-side difference in carrying angle ( P = .481). Conclusion: The elbow carrying angle was not associated with an injury risk during a single season in professional baseball pitchers.
Revision Ulnar Collateral Ligament Reconstruction in Professional Baseball: Current Trends, Surgical Techniques, and Outcomes
Background: Ulnar collateral ligament (UCL) reconstruction of the elbow is commonly performed on professional baseball pitchers. Recent reports have suggested that revision rates are on the rise and may be higher than previously thought. Purpose: To provide a comprehensive report on current trends, surgical techniques, and outcomes of revision UCL reconstructions performed on professional baseball pitchers between 2010 and 2016. Study Design: Case series; Level of evidence, 4. Methods: The Major League Baseball Health and Injury Tracking System (HITS) was used to compile records of all revision UCL reconstructions performed on professional baseball pitchers between 2010 and 2016. Player data and outcomes were obtained from HITS, and surgical details were obtained from operative reports. Descriptive statistical analysis was performed on epidemiologic data. Outcomes (return to play [RTP] rates, RTP times, subsequent injuries, and subsequent surgeries) were compared across the most common surgical techniques (docking vs modified Jobe) and graft sources (palmaris longus autograft vs hamstring autograft). Results: A total of 69 professional baseball pitchers underwent revision UCL reconstruction from 2010 to 2016 at an average of 1424 days (47 months) after their primary surgery. A trend was seen toward increasing numbers of revision surgeries over time ( R 2 = 0.441; P = .104). The most commonly used tunnel configuration was the modified Jobe technique (n = 41; 59.4%), and the most commonly used graft was hamstring autograft (n = 34; 49.3%). A majority (76.6%) of pitchers achieved RTP, and 55.3% were able to return to the same level of play. Mean time to RTP was 436 days (14.5 months) for players with a palmaris longus autograft versus 540 days (18 months) for those with a hamstring autograft ( P = .108). Further, the mean time to RTP was 423 days (14 months) for the docking technique versus 519 days (17 months) for the modified Jobe technique ( P = .296). Similar rates of subsequent injuries and surgeries were noted between the 2 revision techniques and 2 most commonly used graft constructs. Conclusion: Revision UCL reconstruction showed relatively high RTP rates (77%), but only 55% of players returned to their same level of play. Mean time to RTP was shorter than that found in other, smaller investigations. Although general trends were seen toward decreased time to RTP for the docking technique and palmaris longus autograft, these differences did not reach statistical significance.
Reconstruction of the Medial Ulnar Collateral Ligament of the Elbow: Biomechanical Comparison of a Novel Anatomic Technique to the Docking Technique
Background: In recent years, understanding of the anatomy of the ulnar collateral ligament (UCL) has evolved, demonstrating that the insertional footprint of the UCL on the ulna is more elongated and distally tapered than previously described. Current UCL reconstruction configurations do not typically re-create this native anatomy, which may represent a potential area for improvement. Purpose/Hypothesis: The purposes of this study were (1) to describe a novel anatomic UCL reconstruction technique designed to better replicate the native UCL anatomy and (2) to biomechanically compare this with the docking technique. The hypothesis was that the ultimate load to failure for the anatomic technique would not be inferior to the docking technique. Study Design: Controlled laboratory study. Methods: A total of 16 fresh-frozen cadaveric upper extremities (8 matched pairs) were utilized. One elbow in each pair was randomized to receive UCL reconstruction via the docking technique or the novel anatomic UCL reconstruction technique with palmaris tendon autograft. Following reconstruction, biomechanical testing was performed by applying valgus rotational torque at a constant rate of 5 deg/s until ultimate mechanical failure of the construct occurred. Maximal torque (N·m), rotation stiffness (N·m/deg), and mode/location of failure were recorded for each specimen. Results: The mean ultimate load to failure for elbows in the docking technique group was 23.8 ± 6.1 N·m, as compared with 31.9 ± 8.4 N·m in the anatomic technique group ( P = .045). Mean rotational stiffness was 1.9 ± 0.7 versus 2.3 ± 0.9 N·m/deg for the docking and anatomic groups, respectively ( P = .338). The most common mode of failure was suture pullout from the graft, which occurred in all 8 (100%) docking technique specimens and 7 of 8 (88%) specimens that underwent the anatomic UCL reconstruction technique. Conclusion: Ultimately, the anatomic UCL reconstruction technique demonstrated superior strength and resistance to valgus torque when compared with the docking technique, and this was comparable with that of the native UCL from prior studies. Increased initial strength may allow for earlier initiation of throwing postoperatively and potentially shorten return-to-play times. Clinical Relevance: Current UCL reconstruction techniques do not accurately reproduce the UCL insertional anatomy on the ulna. The novel anatomic technique described may result in more natural joint kinematics. This study demonstrated load-to-failure rates that are significantly higher than with the docking technique and consistent with the native ligament, as reported from previous studies. These findings may serve as a foundation for future clinical study and optimization of this technique.
Comparison of Outcomes Based on Graft Type and Tunnel Configuration for Primary Ulnar Collateral Ligament Reconstruction in Professional Baseball Pitchers
Background: Professional baseball pitchers are at high risk for tears of the ulnar collateral ligament (UCL) of the elbow, often requiring surgical reconstruction. Despite acceptable published return-to-play outcomes, multiple techniques and graft types have been described. Purpose: This study compares UCL reconstruction (UCLR) outcomes based on tunnel configuration and graft type. Study Design: Cohort study; Level of evidence, 3. Methods: After approval from our institutional review board and Major League Baseball (MLB), 566 professional baseball pitchers who underwent UCLR between 2010 and 2014 were identified and included. The following patient characteristics were analyzed: age, pitching role (starter vs reliever), level of play (MLB vs Minor League Baseball [MiLB]), and throwing side dominance. Surgical factors analyzed included reconstruction technique, graft type, and concomitant procedures. Primary outcome measures consisted of the ability to return to play at any level (RTP), ability to return to the same level of play (RSL), time to return, subsequent elbow injuries, and need for subsequent or revision elbow surgery. The effects of patient and surgical factors on outcomes were analyzed using multivariate linear and logistic regression modeling. Results: The RTP rate was 79.9%, and the RSL rate was 71.2%. Grafts used to reconstruct the UCL included the palmaris longus autograft (n = 361, 63.7%), the gracilis autograft (n = 135, 23.8%), and other grafts (n = 70, 12.5%). Surgical techniques utilized were the docking technique (n = 171, 30.2%), the modified Jobe technique (n = 290, 51.2%), and other techniques (n = 105, 18.6%). There were no significant differences in the time to RTP or RSL based on reconstruction technique or graft type. RTP rates were similar for the docking versus modified Jobe technique (80.1% vs 82.4%, respectively; P = .537) and for the 2 primary graft types (83.1% for palmaris longus vs 80.7% for gracilis; P = .596). The rate of subsequent elbow surgery was 10.5% for the docking technique versus 14.8% for the modified Jobe technique ( P = .203), and the rate of revision UCLR was 2.9% versus 6.2% for the docking versus modified Jobe technique, respectively ( P = .128). Significant trends toward an increasing use of the palmaris longus autograft ( P = .023) and the docking technique ( P = .006) were observed. MLB pitchers were more likely than MiLB pitchers to RTP ( P < .001) and RSL ( P < .001), but they required a longer time to return (mean difference, 35 days; P = .039) and had a higher likelihood of subsequent elbow (odds ratio [OR], 3.58 [95% CI, 2.06-6.23]; P < .001) and forearm injuries (OR, 5.70 [95% CI, 1.99-16.30]; P = .004) but not subsequent elbow surgery. No specific variables correlated with the rates of subsequent elbow surgery or revision UCLR in the multivariate analysis. The use of concomitant ulnar nerve transposition did not affect outcomes. Conclusion: Surgical outcomes in professional baseball players are not significantly influenced by UCLR technique or graft type. There was a high rate (46.3%) of subsequent throwing elbow injuries. MLB pitchers were more likely to RTP and RSL, but they had a higher frequency of subsequent elbow and forearm injuries than MiLB pitchers. Both the docking technique and the palmaris longus autograft are increasing in popularity among surgeons treating professional baseball players.
The Middle and Distal Aspects of the Ulnar Footprint of the Medial Ulnar Collateral Ligament of the Elbow Do Not Provide Significant Resistance to Valgus Stress: A Biomechanical Study
Background: The medial ulnar collateral ligament (UCL) insertion of the elbow has been shown to extend distally beyond the sublime tubercle. The contribution to valgus stability of the distal aspect of the footprint is unknown. Purpose/Hypothesis: The purpose of this study was to determine the contribution of each part of the UCL footprint to the elbow valgus stability provided by the UCL. It was hypothesized that the distal two-thirds of the ulnar UCL footprint would not contribute significantly to valgus stability provided by the UCL. Study Design: Descriptive laboratory study. Methods: Fifteen cadaveric arms were dissected to the capsuloligamentous elbow structures and potted. A servohydraulic load frame was used to place 5 N·m of valgus stress on the intact elbow at 30°, 60°, 90°, and 120° of flexion. The UCL insertional footprint was measured and divided into thirds (proximal, middle, and distal). One-third of the UCL footprint was elevated off the bone (leaving the ligament in continuity), and the elbow was retested at the same degrees of flexion. This was repeated until the entire UCL footprint on the ulna was sectioned. Each elbow was randomized for how the UCL would be sectioned (sectioning the proximal, then middle, and then distal third or sectioning the distal, then middle, and then proximal third). Ulnohumeral joint gapping (millimeters) was recorded with a 3-dimensional motion capture system using physical and virtual markers. Two-group comparisons were made between each sectioned status versus the intact condition for each flexion angle. Results: When the UCL was sectioned from distal to proximal, none of the ligaments failed prior to complete sectioning. When the UCL was sectioned from proximal to distal, 3 of the 6 ligaments failed after sectioning of the proximal third, while 2 more failed after the proximal and middle thirds were sectioned. Of the specimens with the distal third of the ligament sectioned first, no significant differences were found between intact, distal third cut, and distal plus middle thirds cut at all flexion angles. Conclusion: The middle and distal thirds of the insertional footprint of the UCL on the ulna did not significantly contribute to gap resistance at 5 N·m of valgus load. The proximal third of the footprint is the primary resistor of valgus load. Clinical Relevance: This cadaveric biomechanical study demonstrated that the middle and distal thirds of the native UCL insertion onto the ulna did not significantly contribute to valgus resistance at the elbow. When a UCL reconstruction is performed, the proximal third of the UCL insertion may be the most clinically important portion of the ligament to reconstruct.
Comparison of Outcomes Based on Graft Type and Tunnel Configuration for Primary Ulnar Collateral Ligament Reconstruction in Professional Baseball Pitchers
Objectives: Professional baseball pitchers are at high risk for tears of the ulnar collateral ligament (UCL) of the elbow, often requiring subsequent surgical reconstruction. Despite acceptable published return to play outcomes, multiple techniques and graft types have been described. There is a paucity of clinical data in the current literature comparing UCL reconstruction surgical technique and graft type. Even less is known about the risks for subsequent injury, surgery, or revision UCL reconstruction. Accordingly, this study compares UCL reconstruction outcomes based on tunnel configuration and graft type. Methods: Following approval from our institutional review board and Major League Baseball (MLB), 566 professional baseball pitchers who underwent UCL reconstruction between 2010 and 2014 were identified and included. The following patient demographics were analyzed: age, pitching role (starter vs. reliever), level of play (MLB vs. Minor League Baseball [MiLB]), and throwing side dominance. Surgical factors analyzed included reconstruction technique (Docking vs. Modified Jobe), graft type (palmaris longus autograft vs. gracilis autograft), and concomitant procedures. Primary outcome measures consisted of: the ability to return to play at any level (RTP), to return to the same level of play (RSL), the time to return, subsequent elbow injuries, and the need for subsequent or revision elbow surgery. The impact of the patient and surgical factors on outcomes were analyzed using multivariate linear and logistic regression modeling. Results: The overall RTP was 79.9% and RSL was 71.2%. There were no significant differences in the time to RTP or RSL based on reconstruction technique or graft type. RTP rates were similar for the Docking vs. Modified Jobe techniques (80.1% vs. 82.4%; p=0.537) and for the two primary graft types (83.1% for palmaris vs. 80.7% for gracilis; p=0.596). The risk of subsequent elbow surgery was 10.5% for the Docking Technique vs. 14.8% for the Modified Jobe (p=0.203); and the risk for subsequent UCL revision reconstruction surgery was 2.9% vs. 6.2% for the Docking vs. Modified Jobe Techniques, respectively (p=0.128). Significant trends towards an increasing use of palmaris autograft (p=0.023) and the docking technique (p=0.006) were observed. MLB pitchers were more likely than MiLB pitchers to RTP (p<0.001) and to RSL (p<0.001), but they required a longer time to return (mean difference 35 days; p=0.039), had a higher likelihood of subsequent elbow (OR 3.58; 95% CI 2.055 to 6.231; p<0.001) and forearm injuries (OR 5.695; 95% CI 1.99 to 16.302; p=0.004), but not subsequent elbow surgery. No specific variables were noted to be predictive of subsequent elbow or revision surgery in the multivariate analysis. Conclusion: Surgical outcomes in professional baseball players are not significantly influenced by ulnar collateral ligament reconstruction technique or graft type usage. Major League players are more likely to RTP and RSL, but they have a higher frequency of subsequent elbow and forearm injuries. Both the Docking Technique and palmaris autograft are increasing in popularity amongst surgeons treating professional baseball players.
Disease Burden of Medial Epicondylitis in the USA is Increasing: An Analysis of 19, 856 Patients from 2007 to 2014
Background Medial epicondylitis (ME), or “golfer's elbow,” is often treated initially by conservative means. Up to 15% of recalcitrant cases require surgical intervention, according to small sample populations, but no national study has determined the incidence of the diagnosis or corroborated the rate of surgical intervention. Purpose/Question We sought to review the annual incidence of ME, surgical rates, and health care costs in a population setting. Methods A national database was queried for ME from 2007 to 2014. Annual rates and the percentage of diagnosed cases subjected to surgical intervention were recorded. Epidemiologic data was reported with descriptive statistics, and the significant trends over time were analyzed using linear regression. Results We identified 19, 856 cases of ME in the study period. There was a significant increase in the annual incidence and overall incidence per 10, 000 patients. The proportion of diagnoses in patients under 65 years of age decreased significantly, while the proportion in those 65 years of age or older significantly increased. The annual number of surgical interventions significantly increased over the study period, although the annual proportion of diagnosed cases proceeding to surgery remained constant. The proportion of patients 65 years of age or older undergoing surgery significantly increased. Total reimbursement for the management of ME during the study period was $1, 877,189. While there was a significant increase in the total annual reimbursement, annual per-patient reimbursement did not change significantly. Conclusions While the annual incidence of ME and surgical treatment of ME increased significantly from 2007 to 2014, the proportion of cases treated surgically did not. Notably, the proportion of patients 65 years of age or older diagnosed with and being surgically treated for ME has increased in recent years. Total reimbursement for ME has steadily risen, although per-patient reimbursement rates have not significantly changed.
Patient-Related Risk Factors for Infection Following Ulnar Nerve Release at the Cubital Tunnel: An Analysis of 15,188 Cases
Background: Although cubital tunnel release is a commonly performed orthopaedic procedure, the overall incidence of and independent risk factors for infection largely remain undefined in the current literature. Purpose: To establish the rate of postoperative infection after isolated cubital tunnel release and define relevant patient-related risk factors. Study Design: Case-control study; Level 3. Methods: All Medicare-insured patients undergoing ulnar nerve decompression at the cubital tunnel from 2010 through 2012 were identified. A multivariate binomial logistic regression analysis was utilized to evaluate the impact of patient-related risk factors for postoperative infection. Results: A total of 330 (2.17%) postoperative infections were identified in 15,188 cases. The majority (87%) were managed nonoperatively, while 13% required surgical debridement. The most significant risk factors for infection included hemodialysis use (odds ratio [OR], 2.47), chronic anemia (OR, 2.24), age <65 years (OR, 2.08), tobacco use (OR, 1.65), morbid obesity (OR, 1.53), inflammatory arthritis (OR, 1.43), depression (OR, 1.36), hyperlipidemia (OR, 1.33), male sex (OR, 1.32), and chronic lung disease (OR, 1.29). Conclusion: The present study was adequately powered to determine numerous patient-related risk factors for infection following cubital tunnel release.